CO-ADMINISTRATION OF INTERLEUKIN-3 MUTANTS WITH COLONY STIMULATING FACTORS

Abstract: The present invention relates to human interleukin-3 (hIL-3) variant or mutant proteins (muteins) functionally co-administered with other colony stimulating factors (CSF), cytokines, lymphokines, interleukins, hematopoietic growth factors or IL-3 variants.

Description: CO-ADMINISTRATION OF INTERLEUKIN-3 MUTANTS WITH COLONY STIMULATING FACTORS i \ 5 Field of the Invention The present invention relates to the coadministration or sequential treatment using mutants or variants of human interleukin-3 (hIL-3 ) and other colony stimulating factors (CSFs) , cytokines, 10 lymphokines, interleukins, hematopoietic growth factors or IL-3 variants. Background of the Invention Colony stimulating factors (CSFs) which stimulate 15 the differentiation and/or proliferation of bone marrow cells have generated much interest because of their therapeutic potential for restoring depressed levels of hematopoietic stem cell-derived cells. CSFs in both human and murine systems have been identified and 20 distinguished according to their activities. For example, granulocyte-CSF (G-CSF) and macrophage-CSF (M- CSF) stimulate the in vitro formation of neutrophilic granulocyte and macrophage colonies, respectively while GM-CSF and interleukin-3 (IL-3) have broader activities 25 and stimulate the formation of both macrophage, neutrophilic and eosinophilic granulocyte colonies. IL- 3 also stimulates the formation of mast, megakaryocyte and pure and mixed erythroid colonies (when erythropoietin is also added) . 30 Because of its ability to stimulate the proliferation of a number of different cell types and to support the growth and proliferation of progenitor 1 cells, IL-3 has potential for therapeutic use in restoring hematopoietic cells to normal amounts in those 35 cases where the number of cells has been reduced due to diseases or to therapeutic treatments such as radiation and chemotherapy. Interleukin-3 (IL-3) is a hematopoietic growth factor which has the property of being able to promote the survival, growth and differentiation of hematopoietic cells. Among the biological properties of IL-3 are the ability (a) to support the growth and differentiation of progenitor cells committed to all, or virtually all, blood cell lineages; (b) to interact with early multipotential stem cells; (c) to sustain the growth of pluripotent precursor cells; (d) to stimulate proliferation of chronic myelogenous leukemia (CML) cells; (e) to stimulate proliferation of mast cells, eosinophils and basophils; (f) to stimulate DNA synthesis by human acute myelogenous leukemia (AML) cells; (g) to prime cells for production of leukotrienes and histamines; (h) to induce leukocyte chemotaxis; and (i) to induce cell surface molecules needed for leυkocyte adhesion. Mature human interleukin-3 (hIL-3) consists of 133 amino acids. It has one disulfide bridge and two potential glycosylation sites (Yang, et al. , CELL 47:3 (1986) ) . Murine IL-3 (mIL-3) was first identified by Ihle, et al., J. IMMUNOL. 126:2184 (1981) as a factor which induced expression of a T cell associated enzyme, 20 - hydroxysteroid dehydrogenase. The factor was purified to homogeneity and shown to regulate the growth and differentiation of numerous subclasses of early hematopoietic and lymphoid progenitor cells. In 1984, cDNA clones coding for murine IL-3 were isolated (Fung, et al., NATURE __07.:233 (1984) and Yokota, et al., PROC. NATL. ACAD. SCI. USA 1.1:1070 (1984)) . The murine DNA sequence coded for a polypeptide of 1 6 amino acids including a putative signal peptide. The gibbon IL-3 sequence was obtained using a gibbon cDNA expression library. The gibbon IL-3 sequence was then used as a probe against a human genomic library to obtain a human IL-3 sequence. Gibbon and human genomic DNA homologues of the murine IL-3 sequence were disclosed by Yang, et al. , CELL _T7:3 (1986) . The human sequence reported by Yang, i et al. included a serine residue at position 8 of the \ 5 mature protein sequence. Following this finding, others ' reported isolation of Pro8 hIL-3 cDNAs having proline at position 8 of the protein sequence. Thus it appears that there may be two allelic forms of hIL-3. Dorssers, et al. , GENE 55.115 (1987), found a clone 10 from a human cDNA library which hybridized with mIL-3. This hybridization was the result of the high degree of homology between the 3 ' noncoding regions of mIL-3 and hIL-3. This cDNA coded for an hIL-3 (Pro8) sequence. U.S. 4,877,729 and U.S. 4,959,454 disclose human 15 IL-3 and gibbon IL-3 cDNAs and the protein sequences for which they code. The hIL-3 disclosed has serine rather than proline at position 8 in the protein sequence. Clark-Lewis, et al. , SCIENCE ____1:134 (1986) performed a functional analysis of murine IL-3 analogues 20 synthesized with an automated peptide synthesizer. The authors concluded that the stable tertiary structure of the complete molecule was required for full activity. A study on the role of the disulfide bridges showed that replacement of all four cysteines by alanine gave a 25 molecule with l/500th the activity as the native molecule. Replacement of two of the four Cys residues by Ala(Cys79, Cysl40 -> Ala79, Alal40) resulted in an increased activity. The authors concluded that in murine IL-3 a single disulfide bridge is required 30 between cysteines 17 and 80 to get biological activity that approximates physiological levels and that this structure probably stabilizes the tertiary structure of the protein to give a conformation that is optimal for function. (Clark-Lewis, et al., PROC. NATL. ACAD. SCI. 35 USA _3__:7897 (1988) ) . International Patent Application (PCT) WO 88/00598 discloses gibbon- and human-like IL-3. The hIL-3 contains a Ser8 -> Pro8 replacement. Suggestions are made to replace Cys by Ser, thereby breaking the disulfide bridge, and to replace one or more amino acids at the glycosylation sites. EP-A-0275598 (WO 88/04691) illustrates that Alal can be deleted while retaining biological activity. Some mutant hIL-3 sequences are provided, e.g., two double mutants, Alal -> Aspl, Trpl3 -> Argl3 (pGB/IL- 302) and Alal -> Aspl, Met3 -> τhr3 (pGB/IL-304) and one triple mutant Alal -> Aspl, Leu9 -> Pro9, τ_ 13 -> Argl3 (pGB/IL-303) . WO 88/05469 describes how deglycosylation mutants can be obtained and suggests mutants of Arg54Arg55 and Argl08Argl09LysH0 might avoid proteolysis upon expression in Saccharomyces cerevisiae by KEX2 protease. No mutated proteins are disclosed. Glycosylation and the KEX2 protease activity are only important, in this context, upon expression in yeast. WO 88/06161 mentions various mutants which theoretically may be conformationally and antigenically neutral. The only actually performed mutations are Met 2 -> He2 and Ilel31 -> Leul31. it is not disclosed whether the contemplated neutralities were obtained for these two mutations. WO 91/00350 discloses nonglycosylated hIL-3 analog proteins, for example, hIL-3 (Pro8Aspl5Asp70) . Met rhul-3 (Pro8Aspl5Asp70) ; τhr4 rhuL-3 (Pro8Aspl5Asp70)and Thr β rhulL-3 (Pro8Aspl5Asp70) . i is said that these protein compositions do not exhibit certain adverse side effects associated with native hIL-3 such as urticaria resulting from infiltration of mast cells and lymphocytes into the dermis. The disclosed analog hIL-3 proteins may have N termini at Met3, Thr4, or Thr6. WO 91/12874 discloses cysteine added variants (CAVs) of IL-3 which have at least one Cys residue substituted for a naturally occurring amino acid residue. U.S. 4,810,643 discloses the DNA sequence encoding human G-CSF. WO 91/07988 discloses a method to increase megakaryocyte production comprised of administration of G-CSF with IL-3 or GM-CSF. Also disclosed is a method for increasing platelet production comprised of administration of IL-6 with IL-3, G-CSF or GM-CSF. Summary of the Invention The present invention encompasses recombinant human interleukin-3 (hIL-3) variant or mutant proteins (muteins) These hIL-3 muteins contain one to three amino acid substitutions and may also have amino acid deletions at either/or both the N- and C- termini. This invention encompasses coadministration or sequential treatment using IL-3 variants of the present invention with other colony stimulating factors (CSFs) , cytokines, lymphokines, interleukins, hematopoietic growth factors (herein after collectively referred to as "colony stimulating factors") which may have the potential for therapeutic use in restoring hematopoietic cells to normal amounts in those cases where the number of cells has been reduced due to diseases or to therapeutic treatments such as radiation and/or chemotherapy. Coadministration or sequential treatment using IL-3 variants of the present invention with other colony stimulating factors may enhance therapeutic value due to the synergistic effects of the proteins that make up the treatment. The use of multiple factors may also have the potential advantage by lowering the demands placed on factor-producing cells and their induction systems. If there are limitations in the ability of a cell to produce a factor then by lowering the required concentrations of each of the factors by using them in combination may usefully reduce demands on the factor- producing cells. The use of multiple factors may lower the amount of the factors that would be needed, probably reducing the likelihood of adverse responses. Coadministration or sequential treatment may have the usual activity of the peptides forming the mixture or it may be further characterized by having a biological or physiological activity greater than simply the additive function of the presence of IL-3 or the other growth factors alone. Coadministration or sequential treatment may also unexpectedly provide an enhanced effect on the activity or an activity different from that expected by the presence of IL-3 or the other colony stimulating factors. The IL-3 variants of the present invention may also have an improved activity profile which may include reduction of undesirable biological activities associated with native hIL-3. The present invention includes mutants of hIL-3 in which from 1 to 14 amino acids have been deleted from the N-terminus and/or from 1 to 15 amino acids have been deleted from the C-terminus, containing one to three amino acid substitutions, which are used with other colony stimulating factors or IL-3 variant. Preferred IL-3 variants of the present invention include variants in which amino acids 1 to 14 have been deleted from the N-terminus, amino acids 126 to 133 have been deleted from the C-terminus and contain from one to three amino acid substitutions in the polypeptide sequence. The present invention also provides IL-3 variants which may function as IL-3 antagonists or as discrete antigenic fragments for the production of antibodies useful in immunoassay and immunotherapy protocols. Antagonists of hIL-3 would be particularly useful in blocking the growth of certain cancer cells like AML, CML and certain types of B lymphoid cancers. Other conditions where antagonists would be useful include those in which certain blood cells are produced at abnormally high numbers or are being activated by endogenous ligands. Antagonists would effectively compete for ligands, presumably naturally occurring hemopoietins including and not limited to IL-3, GM-CSF and IL-5, which might trigger or augment the growth of cancer cells by virtue of their ability to bind to the IL-3 receptor complex while intrinsic activation properties of the ligand are diminished. IL-3, GM-CSF and/or IL-5 also play a role in certain asthmatic responses. An antagonist of the IL-3 receptor may have the utility in this disease by blocking receptor- mediated activation and recruitment of inflammatory cells. In addition to the use of the IL-3 variants of the present invention with other colony stimulating factors in vivo, it is envisioned that in vitro uses would include the ability to stimulate bone marrow and blood cell activation and growth before infusion into patients. Brief Description of the Drawings Figure 1 is the human IL-3 gene for E. coli expression (pMON5873), encoding the polypeptide sequence of natural (wild type) human IL-3 [SEQ ID N0.128], plus an initiator methionine, as expressed in E . coli. with the amino acids numbered from the N-terminus of the natural hIL-3. Detailed Description of the Invention The present invention encompasses the coadministration or sequential treatment with recombinant human interleukin-3 (hIL-3) variant or mutant proteins (muteins) with other colony stimulating factors (CSFs) , cytokines, lymphokines, interleukins, hematopoietic growth factors and variants thereof (herein after collectively referred to as "colony stimulating factors)". This invention encompasses the coadministration or sequential treatment using IL-3 variants and other colony stimulating factors colony stimulating factors, each of which may act through a different and specific cell receptor to initiate complementary biological activities. Hematopoiesis requires a complex series of cellular events in which stem cells generate continuously into large populations of maturing cells in all major lineages. There are currently at least 20 known regulators with hematopoietic proliferative activity. Most of these proliferative regulators can stimulate one or another type of colony formation in vitro, the precise pattern of colony formation stimulated by each regulator is quite distinctive. No two regulators stimulate exactly the same pattern of colony formation, as evaluated by colony numbers or, more importantly, by the lineage and maturation pattern of the cells making up the developing colonies. Proliferative responses can most readily be analyzed in simplified in vitro culture systems. Three quite different parameters can be distinguished: alteration in colony size, alteration in colony numbers and cell lineage. Two or more factors may act on the progenitor cell, inducing the formation of larger number of progeny thereby increasing the colony size. Two or more factors may allow increased number of progenitor cells to proliferate either because distinct subsets of progenitors cells exist that respond exclusively to one factor or because some progenitors require stimulation by two or more factors before being able to respond. Activation of additional receptors on a cell by the use of two or more factors is likely to enhance the mitotic signal because of coalescence of initially differing signal pathways into a common final pathway reaching the nucleus (Metcalf, 1989). Other mechanism could explain synergy. For example, if one signalling pathway is limited by an intermediate activation of an additional signalling pathway by a second factor may result in a superadditive response. In some cases, activation of one receptor type can induce an enhanced expression of other receptors (Metcalf, 1993). Two or more factors may result in a different pattern of cell lineages then from a single factor. The use of the IL-3 variants of the present invention with other colony stimulating factors may have the potential .clinical advantage resulting from a proliferative response that is not possible by any single factor. Hematopoietic and other growth factors can be grouped in to two distinct families of related receptors: (1) tyrosine kinase receptors, including those for epidermal growth factor, M-CSF (Sherr, 1990) and SCF (Yarden et al., 1987): and (2) hematopoietic receptors, not containing a tyrosine kinase domain, but exhibiting obvious homology in their extracellular domain (Bazan, 1990). Included in the later group are erythropoietin (D'Andrea et al. , 1989), GM-CSF (Gearing et al. , 1989), IL-3 (Kitamura et al., 1991), G-CSF (Fukunaga et al., 1990), IL-4 (Harada et al. , 1990), IL-5 (Takaki et al. , 1990), IL-6 (Yamasaki et al., 1988), IL-7 (Goodwin et al., 1990), LIF (Gearing et al. , 1991) and IL-2 (Cosman et al. , 1987). Most of the later group of receptors exists in high-affinity form as a heterodimers. After ligand binding, the specific α-chains become associated with at least one other receptor chain (β-chain, γ- chain) . Many of these factors share a common receptor subunit. The α-chains for GM-CSF, IL-3 and IL-5 share the same β-chain (Miyajima et al. , 1992) and receptor complexes for IL-6, LIF and IL-11 share a common β-chain (gpl30) (Taga et al. , 1989; Taga et al. , 1992; Gearing et al., 1992) . The receptor complexs of IL-2, IL-4 and IL-7 share a common γ-chain (Motonari et al. , 1993; Russell et al., 1993; Masayuki et al. , 1993) . GM-CSF accelerates recovery of neutrophils and maintains functional capacity, yet has little demonstrable effect on platelet recovery. In contrast IL-3 promotes a slower increase recovery in neutrophils and monocytes while accelerating the recovery of platelets. Recent studies in normal primates indicate that when IL-3 was administered before GM-CSF that the combination of IL-3 and GM-CSF promoted a synergistic rise in peripheral white blood cells and platelets (Donahue R. E. et al., 1988; Krumwieh D. et al. , 1988; and Stahl C.P. et al. , 1992) . The synergistic effect observed in the sequential combination of IL-3 before GM-CSF may result from the expansion of GM-CSF sensitive cells by IL-3 resulting in a more efficient production of neutrophils. The coadministration of GM-CSF and IL-3 resulted in diminished neutrophils production relative to GM-CSF alone (Farese et al. , 1993). The coadministration of IL-3 and GM-CSF, may result in down regulation of GM-CSF receptors by IL-3 thereby dampening the GM-CSF induced increase in neutrophils. However the coadministration of IL-3 and GM-CSF in a marrow-ablated rhesus monkeys promoted accelerated platelets and neutrophil recovery relative to sequential cytokine treatment or with either IL-3 or GM-CSF alone (Farese et al., 1993). The in vitro activity of both IL-3 and GM-CSF has been shown to be additive with respect to stimulating larger colonies than either cytokine alone (Robinson et al., 1987; Bruno et al. , 1989; Metcalf et al., 1992; Bruno et al., 1991; Bridell et al. , 1990) . Recently IL- 12 has been shown to synergize with IL-3 and c-kit (stem cell factor) to enhance the recovery of hemopoietic stem cells in liquid culture (Ploemacher et al. , 1993). Recent in vitro (Emerson et al. , 1988: Sonodo et' al., 1988) and in vivo (Ganser et al. , 1992; Donahue R. E. et al., 1988; Krumwieh D. et al., 1988; and Stahl C.P. et al., 1992) results of combined IL-3 and GM-CSF treatment suggests an increased clinical efficacy in cytokine combination treatment. As mentioned earlier some of the factors that are involved in hematopoiesis are limited to a specific cell lineage and others have much broader effects and may result in the proliferation and support of multi- lineages and there may be considerable overlap between these factors but that the proliferative profiles are distinct. This suggests that the coadministration or sequential treatment with multiple factors may have a clinical advantage. IL-3 variants of the present invention that have an increased therapeutic index, compared to native IL-3, may have a distinct clinical advantage when coadministered or used sequentially in treatment. The use of multiple factors may also have potential advantage by lowering the demands placed on factor- producing cells and their induction systems. If there are limitations in the ability of a cell to produce a factor then by lowering the required concentrations of each of the factors by using them in combination may usefully reduce demands on the factor-producing cells. The use of multiple factors may lower the amount of the factors that would be needed, probably reducing the likelihood of adverse responses. A non-exclusive list of growth factors, colony stimulating factors (CSFs) include, cytokines, lymphokines, interleukins, and hematopoietic growth factors, which can be used in coadministration or sequential treatment with the hIL-3 variants of the present invention include GM-CSF, CSF-1, G-CSF, Meg-CSF, M-CSF, erythropoietin (EPO), IL-1, IL-4, IL-2, IL-5, IL- 6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13 , LIF, flt3/flk2, human growth hormone, B-cell growth factor, B-cell differentiation factor, eosinophil differentiation factor and stem cell factor (SCF) also known as steel factor or c-kit ligand. The present invention relates to novel variants of human interleukin-3 (hIL-3) in which amino acid substitutions have been made at one to three positions in amino acid sequence of the polypeptide used in sequential treatment or coadministration with other colony stimulating factors. Preferred IL-3 variants of the present invention which have deletions of amino acids 1 to 14 at the N-terminus and 126 to 133 at the C- terminus and which also have one to three amino acid substitutions in the polypeptide used in coadministered or sequential treatment with other colony stimulating factors or IL-3 variants. The present invention includes mutant polypeptides comprising minimally amino acids 15 to 118 of hIL-3 with or without additional amino acid extensions to the N-terminus and/or C- terminus which further contain one to three amino acid substitutions in the amino acid sequence of the polypeptide. As used herein human interleukin-3 corresponds to the amino acid sequence (1-133) as depicted in Figure 1 and (15-125) hIL-3 corresponds to the 15 to 125 amino acid sequence of the hIL-3 polypeptide. Naturally occurring variants of hIL-3 polypeptide amino acids are also included in the present invention (for example, the allele in which proline rather than serine is at position 8 in the hIL-3 polypeptide sequence) as are variant hIL-3 molecules which are modified post- translationally (e.g. glycosylation) . "Mutant amino acid sequence, " "mutant protein" or "mutant polypeptide" refers to a polypeptide having an amino acid sequence which varies from a native sequence or is encoded by a nucleotide sequence intentionally made variant from a native sequence. "Mutant protein," "variant protein" or "mutein" means a protein comprising a mutant amino acid sequence and includes polypeptides which differ from the amino acid sequence of native hlL- 3 due to amino acid deletions, substitutions, or both. "Native sequence" refers to an amino acid or nucleic acid sequence which is identical to a wild-type or native form of a gene or protein. Human IL-3 can be characterized by its ability to stimulate colony formation by human hematopoietic progenitor cells. The colonies formed include erythroid, granulocyte, megakaryocyte, granulocytic macrophages and mixtures thereof. Human IL-3 has demonstrated an ability to restore bone marrow function and peripheral blood cell populations to therapeutically beneficial levels in studies performed initially in primates and subsequently in humans (Gillio, A. P., et al. (1990); Ganser, A, et al. (1990); Falk, S., et al. (1991) . Additional activities of hIL-3 include the ability to stimulate leukocyte migration and chemotaxis; the ability to prime human leukocytes to produce high levels of inflammatory mediators like leukotrienes and histamine; the ability to induce cell surface expression of molecules needed for leukocyte adhesion; and the ability to trigger dermal inflammatory responses and fever. Many or all of these biological activities of hIL-3 involve signal transduction and high affinity receptor binding. Coadministration or sequential treatment using the IL-3 variants of the present invention with other colony stimulating factors may exhibit useful properties such as having similar or greater biological activity when compared to native hlL- 3 or by having improved half-life or decreased adverse side effects, or a combination of these properties. The IL-3 variants of the present invention may also be useful as antagonists. IL-3 variants which have little or no activity when compared to native hIL-3 may still be useful as antagonists, as antigens for the production of antibodies for use in immunology or immunotherapy, as genetic probes or as intermediates used to construct other useful hIL-3 muteins. The use of IL-3 variants of the present invention when coadministered or as part of sequential treatment will preferably have at least one biological property of human IL-3. Coadministration or sequential treatment may also have more than one IL-3-like biological property, or an improved property, or a reduction in an undesirable biological property of human IL-3. Some mutant polypeptides of the present invention may also exhibit an improved side effect profile. For example, 5 they may exhibit a decrease in leukotriene release or histamine release when compared to native hIL-3 or (15- 125) hIL-3. Such hIL-3 or hIL-3-like biological properties may include one or more of the following biological characteristics and in vivo and in vitro 10 activities. One such property is the support of the growth and differentiation of progenitor cells committed to erythroid, lymphoid, and myeloid lineages. For example, in a standard human bone marrow assay, an IL-3-like 15 biological property is the stimulation of granulocytic type colonies, megakaryocytic type colonies, monocyte/macrophage type colonies, and erythroid bursts. Other IL-3-like properties are the interaction with early multipotential stem cells, the sustaining of the 2.0 growth of pluripotent precursor cells, the ability to stimulate chronic myelogenous leukemia (CML) cell proliferation, the stimulation of proliferation of mast cells, the ability to support the growth of various factor-dependent cell lines, and the ability to trigger 25 immature bone marrow cell progenitors. Other biological properties of IL-3 have been disclosed in the art. Human IL-3 also has some biological activities which may in some cases be undesirable, for example the ability to stimulate leukotriene release and the ability to 30 stimulate increased histamine synthesis in spleen and bone marrow cultures and in vivo. Biological activity of hIL-3 and hIL-3 variant proteins of the present invention is determined by DNA synthesis by human acute myelogenous leukemia cells 35 (AML) . The factor-dependent cell line AML 193 was adapted for use in testing biological activity. The biological activity of hIL-3 and hIL-3 variant proteins of the present invention is also determined by counting the colony forming units in a bone marrow assay. Other in vitro cell based assays may also be useful to determine the synergistic effect of multiple colony stimulating factors that comprise the mixture. The following are examples of other useful assays. TF-1 proliferation assay: The TF-1 cell line was derived from bone marrow of a patient with erythroleukemia (Kitamura et al. , 1989). TF-1 cells respond to IL-3, GM-CSF, EPO and IL-5. 32D proliferation assay: 32D is a murine IL-3 dependent cell line which does not respond to human IL-3 but does respond to human G-CSF which is not species restricted. T1165 proliferation assay: T1165 cells are a IL-6 dependent murine cell line (Nordan et al., 1986) which respond to IL-6 and IL-11. Human Plasma Clot meg-CSF Assay: Used to assay megakaryocyte colony formation activity (Mazur et al., 1981) . One object of the present invention is to provide hIL-3 variant with one to three amino acid substitutions in the polypeptide sequence used in coadministration or sequential treatment with other colony stimulating factors or IL-3 variants, which have similar or improved biological activity in relation to native hIL-3 or the other colony stimulating factors or IL-3 variant. The hIL-3 variants of the present invention may have hIL-3 or hIL-3-like activity. For example, they may possess one or more of the biological activities of native hIL-3 and may be useful in stimulating the production of hematopoietic cells by human or primate progenitor cells. The IL-3 variants of the present invention and pharmaceutical compositions containing them may be useful in the treatment of conditions in which hematopoietic cell populations have been reduced or destroyed due to disease or to treatments such as radiation or chemotherapy. Pharmaceutical compositions containing IL-3 variants of the present invention can be administered parenterally, intravenously, or subcutaneously. Native hIL-3 possesses considerable inflammatory activity and has been shown to stimulate synthesis of the arachidonic acid metabolites LTC4, LTD4, and LTE4; histamine synthesis and histamine release. Human clinical trials with native hIL-3 have documented inflammatory responses (Biesma, et al. , BLOOD, 80:1141- 1148 (1992) and Postmus, et al. , J. CLIN. ONCOL., 10.:1131-1140 (1992)). A recent study indicates that leukotrienes were involved in IL-3 actions in vivo and may contribute significantly to the biological effects of IL-3 treatment (Denzlinger, C, et al. , BLOOD, £1:2466-2470 (1993)) Some IL-3 variants of the present invention, when co-administered with other CSFs, cytokines, lymphokines, interleukins, hematopoietic growth factors or IL-3 variants, may have an improved therapeutic profile as compared to native hIL-3 or (15-125)hIL-3. For example, some IL-3 variants of the present invention may have a similar or more potent growth factor activity relative to native hIL-3 or (15-125)hIL-3 without having a similar or corresponding increase in the stimulation of leukotriene or histamine. These IL-3 variants would be expected to have a more favorable therapeutic profile since the amount of polypeptide which needs to be given to achieve the desired growth factor activity (e.g. cell proliferation) would have a diminished leukotriene or histamine stimulating effect. In studies with native hIL-3, the stimulation of inflammatory factors has been an undesirable side effect of the treatment. Reduction or elimination of the stimulation of mediators of inflammation would provide an advantage over the use of native hIL-3. Novel IL-3 variants of the present invention may also be useful as antagonists which block the hIL-3 receptor by binding specifically to it and preventing binding of the agonist. One potential advantage of the novel IL-3 variants of the present invention, particularly those which retain activity similar to or better than that of native hIL-3, is that it may be possible to use a smaller amount of the biologically active mutein to produce the desired therapeutic effect. This may make it possible to reduce the number of treatments necessary to produce the desired therapeutic effect. The use of smaller amounts may also reduce the possibility of any potential antigenic effects or other possible undesirable side effects. For example, if a desired therapeutic effect can be achieved with a smaller amount of polypeptide it may be possible to reduce or eliminate side effects associated with the administration of native IL-3 such as the stimulation of leukotriene and/or histamine release. The novel IL-3 variants of the present invention may also be useful in the activation of stem cells or progenitors which have low receptor numbers. Compounds of this invention are preferably made by genetic engineering techniques now standard in the art United States Patent 4,935,233 and Sambrook et al. , "Molecular Cloning. A Laboratory Manual", Cold Spring Harbor Laboratory (1989)]. One method of creating the preferred hIL-3 (15-125) mutant genes is cassette mutagenesis [Wells, et al. (1985)] in which a portion of the coding sequence of hIL-3 in a plasmid is replaced with synthetic oligonucleotides that encode the desired amino acid substitutions in a portion of the gene between two restriction sites. In a similar manner amino acid substitutions could be made in the full- length hIL-3 gene, or genes encoding variants of hIL-3 in which from 1 to 14 amino acids have been deleted from the N-terminus and/or from 1 to 15 amino acids have been deleted from the C-terminus. When properly assembled these oligonucleotides would encode hIL-3 variants with the desired amino acid substitutions and/or deletions from the N-terminus and/or C-terminus. These and other mutations could be created by those skilled in the art by other mutagenesis methods including; oligonucleotide- directed mutagenesis [Zoller and Smith (1982, 1983, 1984), Smith (1985), Kunkel (1985), Taylor, et al. (1985), Deng and Nickoloff (1992)] or polymerase chain reaction (PCR) techniques [Saiki, (1985)] . Plasmid DNA can be treated with the chosen restriction endonucleases then ligated to the annealed oligonucleotides. The ligated mixtures can be used to transform competent JM101 cells to resistance to an appropriate antibiotic. Single colonies can be picked and the plasmid DNA examined by restriction analysis and/or DNA sequencing to identify plasmids with mutant hIL-3 genes. Suitable cells or cell lines for the production of the proteins claimed in the present invention may be bacterial cells. For example, the various strains of E. coli are well-known as host cells in the field of biotechnology. Examples of such strains include E. coli strains JM101 [Yanish-Perron, et al. (1985)] and MON105 [Obukowicz, et al. (1992)]. Also included in the present invention is the expression of the IL-3 variant protein utilizing a chromosomal expression vector for E. coli based on the bacteriophage Mu (Weinberg et al., 1993). Various strains of B. subtilis may also be employed as host cells for expression of the polypeptides of the present invention. Many strains of yeast cells known to those skilled in the art are also available as host cells for expression of the polypeptides of the present invention. When expressed in the E. coli cytoplasm, the above-mentioned mutant hIL-3 variants of the present invention may also be constructed with Met-Ala- at the N-terminus so that upon expression the Met is cleaved off leaving Ala at the N- terminus. The IL-3 variant proteins of the present invention may include polypeptides having Met-, Ala- or Met-Ala- attached to the N-terminus. When the IL-3 variant polypeptides are expressed in the cytoplasm of E. coli, polypeptides with and without Met attached to the N-terminus are obtained. The N-termini of proteins made in the cytoplasm of E. coli are affected by posttranslational processing by methionine aminopeptidase (Ben-Bassat et al. , 1987) and possibly by other peptidases. These IL-3 variant proteins may also be expressed in E.coli by fusing a signal peptide to the N-terminus. This signal peptide is cleaved from the polypeptide as part of the secretion process. Secretion in E.coli can be used to obtain the correct amino acid at the N-terminus (e.g., Asnl5 in the (15-125) hIL-3 polypeptide) due to the precise nature of the signal peptidase. This is in contrast to the heterogeneity which may be observed at the N-terminus of proteins expressed in the cytoplasm in E.coli. Also suitable for use in the present invention are mammalian cells, such as Chinese hamster ovary cells (CHO) . General methods for expression of foreign genes in mammalian cells are reviewed in: Kaufman, R. J. (1987) High level production of proteins in mammalian cells, in Genetic Engineering, Principles and Methods. Vol. 9, J. K. Setlow, editor, Plenum Press, New York. An expression vector is constructed in which a strong promoter capable of functioning in mammalian cells drives transcription of a eukaryotic secretion signal peptide coding region, which is translationally fused to the coding region for the IL-3 variant. For example, plasmids such as pcDNA I/Neo, pRc/RSV, and pRc/CMV (obtained from Invitrogen Corp., San Diego, California) can be used. The eukaryotic secretion signal peptide coding region can be. from the hIL-3 gene itself or it can be from another secreted mammalian protein (Bayne, M. L. et al. (1987) Proc. Natl. Acad. Sci. USA 84. 2638- 2642) . After construction of the vector containing the hIL-3 variant gene, the vector DNA is transfected into mammalian cells. Such cells can be, for example, the COS7, HeLa, BHK, CHO, or mouse L lines. The cells can be cultured, for example, in DMEM media (JRH Scientific) . The hIL-3 variant secreted into the media can be recovered by standard biochemical approaches following transient expression 24 - 72 hours after transfection of the cells or after establishment of stable cell lines following selection for neomycin resistance. The selection of suitable mammalian host cells and methods for transformation, culture, amplification, screening and product production and purification are known in the art. See, e.g., Gething and Sambrook, Nature. 291:620-625 (1981), or alternatively, Kaufman et al, Mol . Cell. Biol. , 5.(7) :1750-1759 (1985) or Howley et al. , U.S. Pat. No. 4,419,446. Another suitable mammalian cell line is the monkey COS-1 cell line. A similarly useful mammalian cell line is the CV-1 cell line. Where desired, insect cells may be utilized as host cells in the method of the present invention. See, e.g. Miller et al, Genetic Engineering, ϋ:277-298 (Plenum Press 1986) and references cited therein. In addition, general methods for expression of foreign genes in insect cells using Baculovirus vectors are described in: Summers, M. D. and Smith, G. E. (1987) - A manual of methods for Baculovirus vectors and insect cell culture procedures, Texas Agricultural Experiment Station Bulletin No. 1555. An expression vector is constructed comprising a Baculovirus transfer vector, in which a strong Baculovirus promoter (such as the polyhedron promoter) drives transcription of a eukaryotic secretion signal peptide coding region, which is translationally fused to the coding region for the IL-3 variant polypeptide. For example, the plasmid pVLl392 (obtained from Invitrogen Corp., San Diego, California) can be used. After construction of the vector carrying the gene encoding the IL-3 variant polypeptide, two micrograms of this DNA is cotransfected with one microgram of Baculovirus DNA (see Summers & Smith, 1987) into insect cells, strain SF9. Pure recombinant Baculovirus carrying the IL-3 variant gene is used to infect cells cultured, for example, in Excell 401 serum- free medium (JRH Biosciences, Lenexa, Kansas) . The IL-3 variant protein secreted into the medium can be recovered by standard biochemical approaches. Supernatants from mammalian or insect cells expressing the IL-3 variant protein can be first concentrated using any of an number of commercial concentration units. Coadministration or sequential treatment using IL-3 variants of the present invention with other colony stimulating factors may be useful in the treatment of diseases characterized by a decreased levels of either myeloid, erythroid, lymphoid, or megakaryocyte cells of the hematopoietic system or combinations thereof. In addition, they may be used to activate mature myeloid and/or lymphoid cells. Among conditions susceptible to treatment with the polypeptides of the present invention is leukopenia, a reduction in the number of circulating leukocytes (white cells) in the peripheral blood. Leukopenia may be induced by exposure to certain viruses or to radiation. It is often a side effect of various forms of cancer therapy, e.g., exposure to chemotherapeutic drugs, radiation and of infection or hemorrhage. Therapeutic treatment of leukopenia with these IL-3 variants of the present invention with other colony stimulating factors may avoid undesirable side effects caused by treatment with presently available drugs. Coadministration or sequential treatment using IL-3 variants of the present invention with other colony stimulating factors may be useful in the treatment of neutropenia and, for example, in the treatment of such conditions as aplastic anemia, cyclic neutropenia, idiopathic neutropenia, Chediak-Higashi syndrome, systemic lupus erythematosus (SLE) , leukemia, myelodysplastic syndrome and myelofibrosis. The IL-3 variants of the present invention, when coadministered or used in sequential treatment, may be useful in the treatment or prevention of thrombocytopenia. Currently the only therapy for thrombocytopenia is platelet transfusions which are costly and carry the significant risks of infection (HIV, HBV) and alloimunization. The IL-3 variants, when coadministered or used in sequential treatment, may alleviate or diminish the need for platelet transfusions. Severe thrombocytopenia may result from genetic defects such as Fanconi' s Anemia, Wiscott-Aldrich, or May- Hegglin syndromes. Acquired thrombocytopenia may result from auto- or allo-antibodies as in Immune Thrombocytopenia Purpura, Systemic Lupus Erythromatosis, hemolytic anemia, or fetal maternal incompatibility. In addition, splenomegaly, disseminated intravascular coagulation, thrombotic thrombocytopenic purpura, infection or prosthetic heart valves may result in thrombocytopenia. Severe thrombocytopenia may also result from chemotherapy and/or radiation therapy or cancer. Thrombocytopenia may also result from marrow invasion by carcinoma, lymphoma, leukemia or fibrosis. The IL-3 variants of the present invention, when coadministered or used in sequential treatment, may be useful in the mobilization of hematopoietic progenitors and stem cells into peripheral blood. Peripheral blood derived progenitors have been shown to be effective in reconstituting patients in the setting of autologous marrow transplantation. Hematopoietic growth factors including G-CSF and GM-CSF have been shown to enhance the number of circulating progenitors and stem cells in the peripheral blood. This has simplified the procedure for peripheral stem cell collection and dramatically decreased the cost of the procedure by decreasing the number of pheresis required. The IL-3 variants, when coadministered or used in sequential treatment, may be useful in mobilization of stem cells and further enhance the efficacy of peripheral stem cell transplantation. Another projected clinical use of growth factors has been in the in vitro _tivation of hematopoietic progenitors and stem cel-j for gene therapy. In order to have the gene of interest incorporated into the genome of the hematopoietic progenitor or stem cell one needs to stimulate cell division and DNA replication. Hematopoietic stem cells cycle at a very low frequency which means that growth factors may be useful to promote gene transduction and thereby enhance the clinical prospects for gene therapy. Many drugs may cause bone marrow suppression or hematopoietic deficiencies. Examples of such drugs are AZT, DDI, alkylating agents and anti-metabolites used in chemotherapy, antibiotics such as chloramphenicol, penicillin, gancyclovir, daunomycin and sulfa drugs, phenothiazones, tranquilizers such as meprobamate, analgesics such as aminopyrine and dipyrone, anticonvulsants such as phenytoin or carbamazepine, antithyroids such as propylthiouracil and methimazole and diuretics. Coadministration or sequential treatment using IL-3 variants of the present invention with other colony stimulating factors may be useful in preventing or treating the bone marrow suppression or hematopoietic deficiencies which often occur in patients treated with these drugs. Hematopoietic deficiencies may also occur as a result of viral, microbial or parasitic infections and as a result of treatment for renal disease or renal failure, e.g., dialysis. Coadministration or sequential treatment using IL-3 variants of the present invention with other colony stimulating factors may be useful in treating such hematopoietic deficiency. The treatment of hematopoietic deficiency may include administration of a pharmaceutical composition containing the IL-3 variants with other colony stimulating factors to a patient. Coadministration or sequential treatment using IL-3 variants of the present invention with other colony stimulating factors may also be useful for the activation and amplification of hematopoietic precursor cells by treating these cells in vitro with the coadministration or sequential treatment using IL-3 variants of the present invention with other colony stimulating factors prior to injecting the cells into a patient. Various immunodeficiencies e.g., in T and/or B lymphocytes, or immune disorders, e.g., rheumatoid arthritis, may also be beneficially affected by treatment with the coadministration or sequential treatment using IL-3 variants of the present invention with other colony stimulating factors molecules of the present invention. Immunodeficiencies may be the result of viral infections e.g. HTLVI, HTLVII, HTLVIII, severe exposure to radiation, cancer therapy or the result of other medical treatment. IL-3 variants of the present invention may also be employed, alone or in combination with other hematopoietins, in the treatment of other blood cell deficiencies, including thrombocytopenia (platelet deficiency) , or anemia. Other uses for these novel polypeptides are in the treatment of patients recovering from bone marrow transplants in vivo and ex vivo, and in the development of monoclonal and polyclonal antibodies generated by standard methods for diagnostic or therapeutic use. Other aspects of the present invention are methods and therapeutic compositions for treating the conditions referred to above. Such compositions comprise a therapeutically effective amount of one or more of the IL-3 variants of the present invention with other colony stimulating factors in a mixture with a pharmaceutically acceptable carrier. This composition can be administered either parenterally, intravenously or subcutaneously. When administered, the therapeutic composition for use in this invention is preferably in the form of a pyrogen-free, parenterally acceptable aqueous solution. The preparation of such a parenterally acceptable protein solution, having due regard to pH, isotonicity, stability and the like, is within the skill of the art. The dosage regimen involved in a method for treating the above-described conditions will be determined by the attending physician considering various factors which modify the action of drugs, e.g. the condition, body weight, sex and diet of the patient, the severity of any infection, time of administration and other clinical factors. Generally, a daily regimen may be in the range of 0.2 - 150 μg/kg of IL-3 variant protein per kilogram of body weight. This dosage regimen is referenced to a standard level of biological activity which recognizes that native IL-3 generally possesses an EC50 at or about 10 picoMolar to 100 picoMolar in the AML proliferation assay described herein. Therefore, dosages would be adjusted relative to the activity of a given IL-3 variant protein vs. the activity of native (reference) IL-3 and it would not be unreasonable to note that dosage regimens may include doses as low as 0.1 microgram and as high as 1 milligram per kilogram of body weight per day. In addition, there may exist specific circumstances where dosages of IL-3 variant protein would be adjusted higher or lower than the range of 10 - 200 micrograms per kilogram of body weight. These include co-administration with other CSF, cytokine, lymphokine, interleukin, hematopoietic growth factor or IL-3 variant or growth factors; co- administration with chemotherapeutic drugs and/or radiation; the use of glycosylated IL-3 proteins; and various patient-related issues mentioned earlier in this section. As indicated above, the therapeutic method and compositions may also include co-administration with other human factors. A non-exclusive list of other appropriate hematopoietins, CSFs, cytokines, lymphokines, hematopoietic growth factors and interleukins for simultaneous or serial co- administration with the polypeptides of the present invention includes GM-CSF, CSF-1, G-CSF, Meg-CSF, M-CSF, erythropoietin (EPO), IL-1, IL-4, IL-2, IL-5, IL-6, IL- 7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13 , LIF, flt3/flk2, human growth hormone, B-cell growth factor, B-cell differentiation factor and eosinophil differentiation factor, stem cell factor (SCF) also known as steel factor or c-kit ligand, or combinations thereof. The dosage recited above would be adjusted to compensate for such additional components in the therapeutic composition. Progress of the treated patient can be monitored by periodic assessment of the hematological profile, e.g., differential cell count and the like. The present invention includes the following compositions : 1. A composition comprising : A human interleukin-3 mutant polypeptide of the Formula : Ala Pro Met Thr Gin Thr Thr Ser Leu Lys Thr Ser Trp Val Asn 1 5 10 15 Cys Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 20 25 30 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Asn Xaa Xaa Xaa Xaa Xaa Xaa 35 40 45 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 50 55 60 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 65 70 75 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 80 85 90 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 95 100 105 Xaa Phe Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 110 115 120 Xaa Xaa Xaa Gin Gin Thr Thr Leu Ser Leu Ala lie Phe 125 130 [SEQ IDN0.15] wherein Xaa at position 17 is Ser, Lys, Gly, Asp, Met, Gin, or Arg; Xaa at position 18 is Asn, His, Leu, lie, Phe, Arg, or Gin; Xaa at position 19 is Met, Phe, lie, Arg, Gly, Ala, or Cys; Xaa at position 20 is lie, Cys, Gin, Glu, Arg, Pro, or Ala; Xaa at position 21 is Asp, Phe, Lys, Arg, Ala, Gly, Glu, Gin, Asn, Thr, Ser or Val; Xaa at position 22 is Glu, Trp, Pro,' Ser, Ala, His, Asp, Asn, Gin, Leu, Val or Gly; Xaa at position 23 is lie, Val, Ala, Leu, Gly, Trp, Lys, Phe, Leu, Ser, or Arg; Xaa at position 24 is lie, Gly, Val, Arg, Ser, Phe, or Leu; Xaa at position 25 is Thr, His, Gly, Gin, Arg, Pro, or Ala; Xaa at position 26 is His, Thr, Phe, Gly, Arg, Ala, or Trp; Xaa at position 27 is Leu, Gly, Arg, Thr, Ser, or Ala; Xaa at position 28 is Lys, Arg, Leu, Gin, Gly, Pro, Val or Trp; Xaa at position 29 is Gin, Asn, Leu, Pro, Arg, or Val; Xaa at position 30 is Pro, His, Thr, Gly, Asp, Gin, Ser, Leu, or Lys; Xaa at position 31 is Pro, Asp, Gly, Ala, Arg, Leu, or Gin; Xaa at position 32 is Leu, Val, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 33 is Pro, Leu, Gin, Ala, Thr, or Glu; Xaa at position 34 is Leu, Val, Gly, Ser, Lys, Glu, Gin, Thr, Arg, Ala, Phe, lie or Met; Xaa at position 35 is Leu, Ala, Gly, Asn, Pro, Gin, or Val; Xaa at position 36 is Asp, Leu, or Val; Xaa at position 37 is Phe, Ser, Pro, Trp, or lie; Xaa at position 38 is Asn, or Ala; Xaa at position 40 is Leu, Trp, or Arg; Xaa at position 41 is Asn, Cys, Arg, Leu, His, Met, or Pro; Xaa at position 42 is Gly, Asp, Ser, Cys, Asn, Lys, Thr, Leu, Val, Glu, Phe, Tyr, He, Met or Ala; Xaa at position 43 is Glu, Asn, Tyr, Leu, Phe, Asp, Ala, Cys, Gin, Arg, Thr, Gly or Ser; Xaa at position 44 is Asp, Ser, Leu, Arg, Lys, Thr, Met, Trp, Glu, Asn, Gin, Ala or Pro; Xaa at position 45 is Gin, Pro, Phe, Val, Met, Leu, Thr, Lys, Trp, Asp, Asn, Arg, Ser, Ala, He, Glu or His; Xaa at position 46 is Asp, Phe, Ser, Thr, Cys, Glu, Asn, Gin, Lys, His, Ala, Tyr, He, Val or Gly; Xaa at position 47 is He, Gly, Val, Ser, Arg, Pro, or His; Xaa at position 48 is Leu, Ser, Cys, Arg, He, His, Phe, Glu, Lys, Thr, Ala, Met, Val or Asn; Xaa at position 49 is Met, Arg, Ala, Gly, Pro, Asn, His, or Asp; Xaa at position 50 is Glu, Leu, Thr, Asp, Tyr, Lys, Asn, Ser, Ala, He, Val, His, Phe, Met or Gin; Xaa at position 51 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 52 is Asn, His, Arg, Leu, Gly, Ser, or Thr; Xaa at position 53 is Leu, Thr, Ala, Gly, Glu, Pro, Lys, Ser, or Met; Xaa at position 54 is Arg, Asp, He, Ser, Val, Thr, Gin, Asn, Lys, His, Ala or Leu; Xaa at position 55 is Arg, Thr, Val, Ser, Leu, or Gly; Xaa at position 56 is Pro, Gly, Cys, Ser, Gin, Glu, Arg, His, Thr, Ala, Tyr, Phe, Leu, Val or Lys; Xaa at position 57 is Asn or Gly; Xaa at position 58 is Leu, Ser, Asp, Arg, Gin, Val, or Cys; Xaa at position 59 is Glu Tyr, His, Leu, Pro, or Arg; Xaa at position 60 is Ala, Ser, Pro, Tyr, Asn, or Thr; Xaa at position 61 is Phe, Asn, Glu, Pro, Lys, Arg, or Ser; Xaa at position 62 is Asn His, Val, Arg, Pro, Thr, Asp, or lie; Xaa at position 63 is Arg, Tyr, Trp, Lys, Ser, His, Pro, or Val; Xaa at position 64 is Ala, Asn, Pro, Ser, or Lys; Xaa at position 65 is Val, Thr, Pro, His, Leu, Phe, or Ser; Xaa at position 66 is Lys, He, Arg, Val, Asn, Glu, or Ser; Xaa at position 67 is Ser, Ala, Phe, Val, Gly, Asn, He, Pro, or His; Xaa at position 68 is Leu, Val, Trp, Ser, He, Phe, Thr, or His; Xaa at position 69 is Gin, Ala, Pro, Thr, Glu, Arg, Trp, Gly, or Leu; Xaa at position 70 is Asn, Leu, Val, Trp, Pro, or Ala; Xaa at position 71 is Ala, Met, Leu, Pro, Arg, Glu, Thr, Gin, Trp, or Asn; Xaa at position 72 is Ser, Glu, Met, Ala, His, Asn, Arg, or Asp; Xaa at position 73 is Ala, Glu, Asp, Leu, Ser, Gly, Thr, or Arg; Xaa at position 74 is He, Met, Thr, Pro, Arg, Gly, Ala; Xaa at position 75 is Glu, Lys, Gly, Asp, Pro, Trp, Arg, Ser, Gin, or Leu; Xaa at position 76 is Ser, Val, Ala, Asn, Trp, Glu, Pro, Gly, or Asp; Xaa at position 77 is He, Ser, Arg, Thr, or Leu; Xaa at position 78 is Leu, Ala, Ser, Glu, Phe, Gly, or Arg; Xaa at position 79 is Lys, Thr, Asn, Met, Arg, He, Gly, or Asp; Xaa at position 80 is Asn, Trp, Val, Gly, Thr, Leu, Glu, or Arg; Xaa at position 81 is Leu, Gin, Gly, Ala, Trp, Arg, Val, or Lys; Xaa at position 82 is Leu, Gin, Lys, Trp, Arg, Asp, Glu, Asn, His, Thr, Ser, Ala, Tyr, Phe, He, Met or Val; Xaa at position 83 is Pro, Ala, Thr, Trp, Arg, or Met; Xaa at position 84 is Cys, Glu, Gly, Arg, Met, or Val; Xaa at position 85 is Leu, Asn, Val, or Gin; Xaa at position 86 is Pro, Cys, Arg, Ala, or Lys; Xaa at position 87 is Leu, Ser, Trp, or Gly; Xaa at position 88 is Ala, Lys, Arg, Val, or Trp; Xaa at position 89 is Thr, Asp, Cys, Leu, Val, Glu, His, Asn, or Ser; Xaa at position 90 is Ala, Pro, Ser, Thr, Gly, Asp, He, or Met; Xaa at position 91 is Ala, Pro, Ser, Thr, Phe, Leu, Asp, or His; Xaa at position 92 is Pro, Phe, Arg, Ser, Lys, His, Ala, Gly, He or Leu; Xaa at position 93 is Thr, Asp, Ser, Asn, Pro, Ala, Leu, or Arg; Xaa at position 94 is Arg, He, Ser, Glu, Leu, Val, Gin, Lys, His, Ala, or Pro; Xaa at position 95 is His, Gin, Pro, Arg, Val, Leu, Gly, Thr, Asn, Lys, Ser, Ala, Trp, Phe, He, or Tyr; Xaa at position 96 is Pro, Lys, Tyr, Gly, He, or Thr; Xaa at position 97 is He, Val, Lys, Ala, or Asn; Xaa at position 98 is His, He, Asn, Leu, Asp, Ala, Thr, Glu, Gin, Ser, Phe, Met, Val, Lys, Arg, Tyr or Pro; Xaa at position 99 is He, Leu, Arg, Asp, Val, Pro, Gin, Gly, Ser, Phe, or His; Xaa at position 100 is Lys, Tyr, Leu, His, Arg, He, Ser, Gin, or Pro; Xaa at position 101 is Asp, Pro, Met, Lys, His, Thr, Val, Tyr, Glu, Asn, Ser, Ala, Gly, He, Leu, or Gin; Xaa at position 102 is Gly, Leu, Glu, Lys, Ser, Tyr, or Pro; Xaa at position 103 is Asp, or Ser; Xaa at position 104 is Trp, Val, Cys, Tyr, Thr, Met, Pro, Leu, Gin, Lys, Ala, Phe, or Gly; Xaa at position 105 is Asn, Pro, Ala, Phe, Ser, Trp, Gin, Tyr, Leu, Lys, He, Asp, or His; Xaa at position 106 is Glu, Ser, Ala, Lys, Thr, He, Gly, or Pro; Xaa at position 108 is Arg, Lys, Asp, Leu, Thr, He, Gin, His, Ser, Ala or Pro; Xaa at position 109 is Arg, Thr, Pro, Glu, Tyr, Leu, Ser, or Gly; Xaa at position 110 is Lys, Ala, Asn, Thr, Leu, Arg, Gin, His, Glu, Ser, Ala, or Trp; Xaa at position 111 is Leu, He, Arg, Asp, or Met; Xaa at position 112 is Thr, Val, Gin, Tyr, Glu, His, Ser, or Phe; Xaa at position 113 is Phe, Ser, Cys, His, Gly, Trp, Tyr, Asp, Lys, Leu, He, Val or Asn; Xaa at position 114 is Tyr, Cys, His, Ser, Trp, Arg, or Leu; Xaa at position 115 is Leu, Asn, Val, Pro, Arg, Ala, His, Thr, Trp, or Met; Xaa at position 116 is Lys, Leu, Pro, Thr, Met, Asp, Val, Glu, Arg, Trp, Ser, Asn, His, Ala, Tyr, Phe, Gin, or lie; Xaa at position 117 is Thr, Ser, Asn, He, Trp, Lys, or Pro; Xaa at position 118 is Leu, Ser, Pro, Ala, Glu, Cys, Asp, or Tyr; Xaa at position 119 is Glu, Ser, Lys, Pro, Leu, Thr, Tyr, or Arg; Xaa at position 120 is Asn, Ala, Pro, Leu, His, Val, or Gin; Xaa at position 121 is Ala, Ser, He, Asn, Pro, Lys, Asp, or Gly; Xaa at position 122 is Gin, Ser, Met, Trp, Arg, Phe, Pro, His, He, Tyr, or Cys; Xaa at position 123 is Ala, Met, Glu, His, Ser, Pro, Tyr, or Leu; and which can additionally have Met- preceding the amino acid in position 1; and wherein from 1 to 14 amino acids can be deleted from the N-terminus and/or from 1 to 15 amino acids can be deleted from the C-terminus; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native (1- 133) human interleukin-3; A colony stimulating factor selected from the group consisting of GM-CSF, CSF-1, G-CSF, Meg-CSF, M-CSF, erythropoietin (EPO), IL-1, IL-4, IL-2, IL- 5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13, LIF, flt3/flk2, human growth hormone, B- cell growth factor, B-cell differentiation factor and eosinophil differentiation factor, stem cell factor (SCF) ; and At least one non-toxic pharmaceutically acceptable carrier. Preferably the CSF is G-CSF or GM-GSF more preferably the CSF is G-CSF. 2. A composition, comprising: A human interleukin-3 mutant polypeptide of the Formula: Ala Pro Met Thr Gin Thr Thr Ser Leu Lys Thr Ser Trp Val Asn 1 5 10 15 Cys Xaa Xaa Xaa He Xaa Glu Xaa Xaa Xaa Xaa Leu Lys Xaa Xaa 20 25 30 Xaa Xaa Xaa Xaa Xaa Asp Xaa Xaa Asn Leu Asn Xaa Glu Xaa Xaa 35 40 45 Xaa He Leu Met Xaa Xaa Asn Leu Xaa Xaa Xaa Asn Leu Glu Xaa 50 55 60 Phe Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Asn Xaa Xaa Xaa He Glu 65 70 75 Xaa Xaa Leu Xaa Xaa Leu Xaa Xaa Cys Xaa Pro Xaa Xaa Thr Ala 80 85 90 Xaa Pro Xaa Arg Xaa Xaa Xaa Xaa Xaa Xaa Xaa Gly Asp Xaa Xaa 95 100 105 Xaa Phe Xaa Xaa Lys Leu Xaa Phe Xaa Xaa Xaa Xaa Leu Glu Xaa 110 115 120 Xaa Xaa Xaa Gin Gin Thr Thr Leu Ser Leu Ala He Phe 125 130 [SEQ ID NO:17] wherein Xaa at position 17 is Ser, Gly, Asp, Met, or Gin; Xaa at position 18 is Asn, His, or lie; Xaa at position 19 is Met or lie; Xaa at position 21 is Asp or Glu; Xaa at position 23 is He, Ala, Leu, or Gly; Xaa at position 24 is He, Val, or Leu; Xaa at position 25 is Thr, His, Gin, or Ala; Xaa at position 26 is His or Ala; Xaa at position 29 is Gin, Asn, or Val; Xaa at position 30 is Pro, Gly, or Gin; Xaa at position 31 is Pro, Asp, Gly, or Gin; Xaa at position 32 is Leu, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 33 is Pro or Glu; Xaa at position 34 is Leu, Val, Gly, Ser, Lys, Ala, Arg, Gin, Glu, He, Phe, Thr or Met; Xaa at position 35 is Leu, Ala, Asn, Pro, Gin, or Val; Xaa at position 37 is Phe, Ser, Pro, or Trp; Xaa at position 38 is Asn or Ala; Xaa at position 42 is Gly, Asp, Ser, Cys, Ala, Asn, He, Leu, Met, Tyr or Arg; Xaa at position 44 is Asp or Glu; Xaa at position 45 is Gin, Val, Met, Leu, Thr, Ala, Asn, Glu, Ser or Lys; Xaa at position 46 is Asp, Phe, Ser, Thr, Ala, Asn Gin, Glu, His, He, Lys, Tyr, Val or Cys; Xaa at position 50 is Glu, Ala, Asn, Ser or Asp; Xaa at position 51 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 54 is Arg or Ala; Xaa at position 55 is Arg, Thr, Val, Leu, or Gly; Xaa at position 56 is Pro, Gly, Ser, Gin, Ala, Arg, Asn, Glu, Leu, Thr, Val or Lys; Xaa at position 60 is Ala or Ser; Xaa at position 62 is Asn, Pro, Thr, or lie; Xaa at position 63 is Arg or Lys; Xaa at position 64 is Ala or Asn; Xaa at position 65 is Val or Thr; Xaa at position 66 is Lys or Arg; Xaa at position 67 is Ser, Phe, or His; Xaa at position 68 is Leu, He, Phe, or His; Xaa at position 69 is Gin, Ala, Pro, Thr, Glu, Arg, or Gly; Xaa at position 71 is Ala, Pro, or Arg; Xaa at position 72 is Ser, Glu, Arg, or Asp; Xaa at position 73 is Ala or Leu; Xaa at position 76 is Ser, Val, Ala, Asn, Glu, Pro, or Gly; Xaa at position 77 is He or Leu; Xaa at position 79 is Lys, Thr, Gly, Asn, Met, Arg, He, Gly, or Asp; Xaa at position 80 is Asn, Gly, Glu, or Arg; Xaa at position 82 is Leu, Gin, Trp, Arg, Asp, Ala, Asn, Glu, His, He, Met, Phe, Ser, Thr, Tyr or Val; Xaa at position 83 is Pro or Thr; Xaa at position 85 is Leu or Val; Xaa at position 87 is Leu or Ser; Xaa at position 88 is Ala or Trp; Xaa at position 91 is Ala or Pro; Xaa at position 93 is Thr, Asp, Ser, Pro, Ala, Leu, or Arg; Xaa at position 95 is His, Pro, Arg, Val, Leu, Gly, Asn, Phe, Ser or Thr; Xaa at position 96 is Pro or Tyr; Xaa at position 97 is He or Val; Xaa at position 98 is His, He, Asn, Leu, Ala, Thr, Leu, Arg, Gin, Leu, Lys, Met, Ser, Tyr, Val or Pro; Xaa at position 99 is He, Leu, or Val; Xaa at position 100 is Lys, Arg, He, Gin, Pro, or Ser; Xaa at position 101 is Asp, Pro, Met, Lys, His, Thr, Pro, Asn, He, Leu or Tyr; Xaa at position 104 is Trp or Leu; Xaa at position 105 is Asn, Pro, Ala, Ser, Trp, Gin, Tyr, Leu, Lys, He, Asp, or His; Xaa at position 106 is Glu or Gly; Xaa at position 108 is Arg, Ala, or Ser; Xaa at position 109 is Arg, Thr, Glu, Leu, or Ser; Xaa at position 112 is Thr, Val, or Gin; Xaa at position 114 is Tyr or Trp; Xaa at position 115 is Leu or Ala; Xaa at position 116 is Lys, Thr, Val, Trp, Ser, Ala, His, Met, Phe, Tyr or lie; Xaa at position 117 is Thr or Ser; Xaa at position 120 is Asn, Pro, Leu, His, Val, or Gin; Xaa at position 121 is Ala, Ser, He, Asn, Pro, Asp, or Gly; Xaa at position 122 is Gin, Ser, Met, Trp, Arg, Phe, Pro, His, He, Tyr, or Cys; Xaa at position 123 is Ala, Met, Glu, His, Ser, Pro, Tyr, or Leu. and which can additionally have Met- preceding the amino acid in position 1; and wherein from 1 to 14 amino acids can be deleted from the N-terminus and/or from 1 to 15 amino acids can be deleted from the C-terminus; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native (1- 133)human interleukin-3; A colony stimulating factor ; and At least one non-toxic pharmaceutically acceptable carrier. 3. The composition of 2, wherein said human interleukin-3 mutant polypeptide is of the Formula: Ala Pro Met Thr Gin Thr Thr Ser Leu Lys Thr Ser Trp Val Asn 1 5 10 15 Cys Xaa Xaa Met He Asp Glu Xaa He Xaa Xaa Leu Lys Xaa Xaa 20 25 30 Pro Xaa Pro Xaa Xaa Asp Phe Xaa Asn Leu Asn Xaa Glu Asp Xaa 35 40 45 Xaa He Leu Met Xaa Xaa Asn Leu Arg Xaa Xaa Asn Leu Glu Ala 50 55 60 Phe Xaa Arg Xaa Xaa Lys Xaa Xaa Xaa Asn Ala Ser Ala He Glu 65 70 75 Xaa Xaa Leu Xaa Xaa Leu Xaa Pro Cys Leu Pro Xaa Xaa Thr Ala 80 85 90 Xaa Pro Xaa Arg Xaa Pro He Xaa Xaa Xaa Xaa Gly Asp Trp Xaa 95 100 105 Glu Phe Xaa Xaa Lys Leu Xaa Phe Tyr Leu Xaa Xaa Leu Glu Xaa 110 115 120 Xaa Xaa Xaa Gin Gin Thr Thr Leu Ser Leu Ala He Phe 125 130 [SEQ ID NO:18] wherein Xaa at position 17 is Ser, Gly, Asp, or Gin; Xaa at position 18 is Asn, His, or lie; Xaa at position 23 is He, Ala, Leu, or Gly; Xaa at position 25 is Thr, His, or Gin; Xaa at position 26 is His or Ala; Xaa at position 29 is Gin or Asn; Xaa at position 30 is Pro or Gly; Xaa at position 32 is Leu, Arg, Asn, or Ala; Xaa at position 34 is Leu, Val, Ser, Ala, Arg, Gin, Glu, He, Phe, Thr, or Met; Xaa at position 35 is Leu, Ala, Asn, or Pro; Xaa at position 38 is Asn or Ala; Xaa at position 42 is Gly, Asp, Ser, Ala, Asn, He, Leu, Met, Tyr or Arg; Xaa at position 45 is Gin, Val, Met, Leu, Ala, Asn, Glu, or Lys; Xaa at position 46 is Asp, Phe, Ser, Gin, Glu, His, Val or Thr; Xaa at position 50 is Glu Asn, Ser or Asp; Xaa at position 51 is Asn, Arg, Pro, Thr, or His; Xaa at position 55 is Arg, Leu, or Gly; Xaa at position 56 is Pro, Gly, Ser, Ala, Asn, Val, Leu or Gin; Xaa at position 62 is Asn, Pro, or Thr; Xaa at position 64 is Ala or Asn; Xaa at position 65 is Val or Thr; Xaa at position 67 is Ser or Phe; Xaa at position 68 is Leu or Phe; Xaa at position 69 is Gin, Ala, Glu, or Arg; Xaa at position 76 is Ser, Val, Asn, Pro, or Gly; Xaa at position 77 is He or Leu; Xaa at position 79 is Lys, Gly, Asn, Met, Arg, He, or Gly; Xaa at position 80 is Asn, Gly, Glu, or Arg; Xaa at position 82 is Leu, Gin, Trp, Arg, Asp, Asn, Glu, His, Met, Phe, Ser, Thr, Tyr or Val; Xaa at position 87 is Leu or Ser; Xaa at position 88 is Ala or Trp; Xaa at position 91 is Ala or Pro; Xaa at position 93 is Thr, Asp, or Ala; Xaa at position 95 is His, Pro, Arg, Val, Gly, Asn, Ser or Thr; Xaa at position 98 is His, He, Asn, Ala, Thr, Gin, Glu, Lys, Met, Ser, Tyr, Val or Leu; Xaa at position 99 is He or Leu; Xaa at position 100 is Lys or Arg; Xaa at position 101 is Asp, Pro, Met, Lys, Thr, His, Pro, Asn, He, Leu or Tyr; Xaa at position 105 is Asn, Pro, Ser, He or Asp; Xaa at position 108 is Arg, Ala, or Ser; Xaa at position 109 is Arg, Thr, Glu, Leu, or Ser; Xaa at position 112 is Thr or Gin; Xaa at position 116 is Lys, Val, Trp, Ala, His, Phe, Tyr or lie; Xaa at position 117 is Thr or Ser; Xaa at position 120 is Asn, Pro, Leu, His, Val, or Gin; Xaa at position 121 is Ala, Ser, He, Pro, or Asp; Xaa at position 122 is Gin, Met, Trp, Phe, Pro, His, He, or Tyr; Xaa at position 123 is Ala, Met, Glu, Ser, or Leu; and which can additionally have Met- preceding the amino acid in position 1; and wherein from 1 to 14 amino acids can be deleted from the N-terminus and/or from 1 to 15 amino acids can be deleted from the C-terminus; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native (1- 133)human interleukin-3. 4. The composition of 3, wherein said human interleukin-3 mutant polypeptide is of the Formula : Xaa at position 42 is Gly, Asp, Ser, He, Leu, Met, Tyr, or Ala; Xaa at position 45 is Gin, Val, Met or Asn; Xaa at position 46 is Asp, Ser, Gin, His or Val; Xaa at position 50 is Glu or Asp; Xaa at position 51 is Asn, Pro or Thr; Xaa at position 62 is Asn or Pro; Xaa at position 76 is Ser, or Pro; Xaa at position 82 is Leu, Trp, Asp, Asn Glu, His, Phe, Ser or Tyr; Xaa at position 95 is His, Arg, Thr, Asn or Ser; Xaa at position 98 is His, He, Leu, Ala, Gin, Lys, Met, Ser, Tyr or Val; Xaa at position 100 is Lys or Arg; Xaa at position 101 is Asp, Pro, His, Asn, He or Leu; Xaa at position 105 is Asn, or Pro; Xaa at position 108 is Arg, Ala, or Ser; Xaa at position 116 is Lys, Val, Trp, Ala, His, Phe, or Tyr; Xaa at position 121 is Ala, or lie; Xaa at position 122 is Gin, or He; and Xaa at position 123 is Ala, Met or Glu. 5. The composition, comprising: A human interleukin-3 mutant polypeptide of the Formula: Asn Cys Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 1 5 10 15 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Asn Xaa Xaa Xaa Xaa Xaa 20 25 30 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 35 40 45 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 50 55 60 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 65 70 75 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 80 85 90 Xaa Xaa Phe Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 95 100 105 Xaa Xaa Xaa Xaa Gin Gin [SEQ ID NO:19] 110 wherein Xaa at position 3 is Ser, Lys, Gly, Asp, Met, Gin, or Arg Xaa at position 4 is Asn, His, Leu, He, Phe, Arg, or Gin Xaa at position 5 is Met, Phe, He, Arg, Gly, Ala, or Cys Xaa at position 6 is He, Cys, Gin, Glu, Arg, Pro, or Ala Xaa at position 7 is Asp, Phe, Lys, Arg, Ala, Gly, Glu, Gin, Asn, Thr, Ser or Val; Xaa at position 8 is Glu, Trp, Pro, Ser, Ala, His, Asp, Asn, Gin, Leu, Val, or Gly; Xaa at position 9 is He, Val, Ala, Leu, Gly, Trp, Lys, Phe, Leu, Ser, or Arg; Xaa at position 10 is He, Gly, Val, Arg, Ser, Phe, or Leu; Xaa at position 11 is Thr, His, Gly, Gin, Arg, Pro, or Ala; Xaa at position 12 is His, Thr, Phe, Gly, Arg, Ala, or Trp; Xaa at position 13 is Leu, Gly, Arg, Thr, Ser, or Ala; Xaa at position 14 is Lys, Arg, Leu, Gin, Gly, Pro, Val or Trp; Xaa at position 15 is Gin, Asn, Leu, Pro, Arg, or Val; Xaa at position 16 is Pro, His, Thr, Gly, Asp, Gin, Ser, Leu, or Lys; Xaa at position 17 is Pro, Asp, Gly, Ala, Arg, Leu, or Gin; Xaa at position 18 is Leu, Val, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 19 is Pro, Leu, Gin, Ala, Thr, or Glu; Xaa at position 20 is Leu, Val, Gly, Ser, Lys, Glu, Gin, Thr, Arg, Ala, Phe, He or Met; Xaa at position 21 is Leu, Ala, Gly, Asn, Pro, Gin, or Val; Xaa at position 22 is Asp, Leu, or Val; Xaa at position 23 is Phe, Ser, Pro, Trp, or lie; Xaa at position 24 is Asn, or Ala; Xaa at position 26 is Leu, Trp, or Arg; Xaa at position 27 is Asn, Cys, Arg, Leu, His, Met, Pro; Xaa at position 28 is Gly, Asp, Ser, Cys, Ala, Lys, Asn, Thr, Leu, Val, Glu, Phe, Tyr, He or Met; Xaa at position 29 is Glu, Asn, Tyr, Leu, Phe, Asp, Ala, Cys, Gin, Arg, Thr, Gly or Ser; Xaa at position 30 is Asp, Ser, Leu, Arg, Lys, Thr,Met, Trp, Glu, Asn, Gin, Ala or Pro; Xaa at position 31 is Gin, Pro, Phe, Val, Met, Leu, Thr, Lys, Asp, Asn, Arg, Ser, Ala, He, Glu, His or Trp; Xaa at position 32 is Asp, Phe, Ser, Thr, Cys, Glu, Asn, Gin, Lys, His, Ala, Tyr, He, Val or Gly; Xaa at position 33 is He, Gly, Val, Ser, Arg, Pro, or His; Xaa at position 34 is Leu, Ser, Cys, Arg, He, His, Phe, Glu, Lys, Thr, Ala, Met, Val or Asn; Xaa at position 35 is Met, Arg, Ala, Gly, Pro, Asn, His, or Asp; Xaa at position 36 is Glu, Leu, Thr, Asp, Tyr, Lys, Asn, Ser, Ala, He, Val, His, Phe, Met or Gin; Xaa at position 37 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 38 is Asn, His, Arg, Leu, Gly, Ser, or Thr; Xaa at position 39 is Leu, Thr, Ala, Gly, Glu, Pro, Lys, Ser, Met, or; Xaa at position 40 is Arg, Asp, He, Ser, Val, Thr, Gin, Asn, Lys, His, Ala or Leu; Xaa at position 41 is Arg, Thr, Val, Ser, Leu, or Gly; Xaa at position 42 is Pro, Gly, Cys, Ser, Gin, Glu, Arg, His, Thr, Ala, Tyr, Phe, Leu, Val or Lys; Xaa at position 43 is Asn or Gly; Xaa at position 44 is Leu, Ser, Asp, Arg, Gin, Val, or Cys; Xaa at position 45 is Glu Tyr, His, Leu, Pro, or Arg; Xaa at position 46 is Ala, Ser, Pro, Tyr, Asn, or Thr; Xaa at position 47 is Phe, Asn, Glu, Pro, Lys, Arg, or Ser; Xaa at position 48 is Asn, His, Val, Arg, Pro, Thr, Asp, or lie; Xaa at position 49 is Arg, Tyr, Trp, Lys, Ser, His, Pro, or Val; Xaa at position 50 is Ala, Asn, Pro, Ser, or Lys; Xaa at position 51 is Val, Thr, Pro, His, Leu, Phe, or Ser; Xaa at position 52 is Lys, He, Arg, Val, Asn, Glu, or Ser; Xaa at position 53 is Ser, Ala, Phe, Val, Gly, Asn, He, Pro, or His; Xaa at position 54 is Leu, Val, Trp, Ser, He, Phe, Thr, or His; Xaa at position 55 is Gin, Ala, Pro, Thr, Glu, Arg, Trp, Gly, or Leu; Xaa at position 56 is Asn, Leu, Val, Trp, Pro, or Ala; Xaa at position 57 is Ala, Met, Leu, Pro, Arg, Glu, Thr, Gin, Trp, or Asn; Xaa at position 58 is Ser, Glu, Met, Ala, His, Asn, Arg, or Asp; Xaa at position 59 is Ala, Glu, Asp, Leu, Ser, Gly, Thr, or Arg; Xaa at position 60 is He, Met, Thr, Pro, Arg, Gly, Ala; Xaa at position 61 is Glu, Lys, Gly, Asp, Pro, Trp, Arg, Ser, Gin, or Leu; Xaa at position 62 is Ser, Val, Ala, Asn, Trp, Glu, Pro, Gly, or Asp; Xaa at position 63 is He, Ser, Arg, Thr, or Leu; Xaa at position 64 is Leu, Ala, Ser, Glu, Phe, Gly, or Arg; Xaa at position 65 is Lys, Thr, Gly, Asn, Met, Arg, He, or Asp; Xaa at position 66 is Asn, Trp, Val, Gly, Thr, Leu, Glu, or Arg; Xaa at position 67 is Leu, Gin, Gly, Ala, Trp, Arg, Val, or Lys; Xaa at position 68 is Leu, Gin, Lys, Trp, Arg, Asp, Glu, Asn, His, Thr, Ser, Ala, Tyr, Phe, He, Met or Val; Xaa at position 69 is Pro, Ala, Thr, Trp, Arg, or Met; Xaa at position 70 is Cys, Glu, Gly, Arg, Met, or Val; Xaa at position 71 is Leu, Asn, Val, or Gin; Xaa at position 72 is Pro, Cys, Arg, Ala, or Lys; Xaa at position 73 is Leu, Ser, Trp, or Gly; Xaa at position 74 is Ala, Lys, Arg, Val, or Trp; Xaa at position 75 is Thr, Asp, Cys, Leu, Val, Glu, His, Asn, or Ser; Xaa at position 76 is Ala, Pro, Ser, Thr, Gly, Asp, He, or Met; Xaa at position 77 is Ala, Pro, Ser, Thr, Phe, Leu, Asp, or His; Xaa at position 78 is Pro, Phe, Arg, Ser, Lys, His, Ala, Gly, He or Leu; Xaa at position 79 is Thr, Asp, Ser, Asn, Pro, Ala, Leu, or Arg; Xaa at position 80 is Arg, He, Ser, Glu, Leu, Val, Gin, Lys, His, Ala or Pro; Xaa at position 81 is His, Gin, Pro, Arg, Val, Leu, Gly, Thr, Asn, Lys, Ser, Ala, Trp, Phe, He or Tyr; Xaa at position 82 is Pro, Lys, Tyr, Gly, He, or Thr; Xaa at position 83 is He, Val, Lys, Ala, or Asn; Xaa at position 84 is His, He, Asn, Leu, Asp, Ala, Thr, Glu, Gin, Ser, Phe, Met, Val, Lys, Arg, Tyr or Pro; Xaa at position 85 is He, Leu, Arg, Asp, Val, Pro, Gin, Gly, Ser, Phe, or His; Xaa at position 86 is Lys, Tyr, Leu, His, Arg, He, Ser, Gin, Pro; Xaa at position 87 is Asp, Pro, Met, Lys, His, Thr, Val, Tyr, Glu, Asn, Ser, Ala, Gly, He, Leu or Gin; Xaa at position 88 is Gly, Leu, Glu, Lys, Ser, Tyr, or Pro; Xaa at position 89 is Asp, or Ser; Xaa at position 90 is Trp, Val, Cys, Tyr, Thr, Met, Pro, Leu, Gin, Lys, Ala, Phe, or Gly; Xaa at position 91 is Asn, Pro, Ala, Phe, Ser, Trp, Gin, Tyr, Leu, Lys, He, Asp, or His; Xaa at position 92 is Glu, Ser, Ala, Lys, Thr, He, Gly, or Pro; Xaa at position 94 is Arg, Lys, Asp, Leu, Thr, He, Gin, His, Ser, Ala, or Pro; Xaa at position 95 is Arg, Thr, Pro, Glu, Tyr, Leu, Ser, or Gly; Xaa at position 96 is Lys, Asn, Thr, Leu, Gin, Arg, His, Glu, Ser, Ala or Trp; Xaa at position 97 is Leu, He, Arg, Asp, or Met; Xaa at position 98 is Thr, Val, Gin, Tyr, Glu, His, Ser, or Phe; Xaa at position 99 is Phe, Ser, Cys, His, Gly, Trp, Tyr, Asp, Lys, Leu, He, Val or Asn; Xaa at position 100 is Tyr, Cys, His, Ser, Trp, Arg, or Leu; Xaa at position 101 is Leu, Asn, Val, Pro, Arg, Ala, His, Thr, Trp, or Met; Xaa at position 102 is Lys, Leu, Pro, Thr, Met, Asp, Val, Glu, Arg, Trp, Ser, Asn, His, Ala, Tyr, Phe, Gin, or lie; Xaa at position 103 is Thr, Ser, Asn, He, Trp, Lys, or Pro; '' Xaa at position 104 is Leu, Ser, Pro, Ala, Glu, Cys, Asp, or Tyr; Xaa at position 105 is Glu, Ser, Lys, Pro, Leu, Thr, Tyr, or Arg; Xaa at position 106 is Asn, Ala, Pro, Leu, His, Val, or Gin; Xaa at position 107 is Ala, Ser, He, Asn, Pro, Lys, Asp, or Gly; Xaa at position 108 is Gin, Ser, Met, Trp, Arg, Phe, Pro, His, He, Tyr, or Cys; Xaa at position 109 is Ala, Met, Glu, His, Ser, Pro, Tyr, or Leu; and which can additionally have Met- or Met -Ala- preceding the amino acid in position 1 ; and wherein from 1 to 3 of the amino acids designated by Xaa are dif ferent from the corresponding native amino acids of ( 1-133 ) human interleukin-3 ; A colony stimulating factor ; and At least one non-toxic pharmaceutically acceptable carrier . 6. The composition of 5 , wherein said human interleukin-3 mutant polypeptide is of the Formula : Asn Cys Xaa Xaa Xaa He Xaa Glu Xaa Xaa Xaa Xaa Leu Lys Xaa 1 5 10 15 Xaa Xaa Xaa Xaa Xaa Xaa Asp Xaa Xaa Asn Leu Asn Xaa Glu Xaa 20 25 30 Xaa Xaa He Leu Met Xaa Xaa Asn Leu Xaa Xaa Xaa Asn Leu Glu 35 40 45 Xaa Phe Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Asn Xaa Xaa Xaa He 50 55 60 Glu Xaa Xaa Leu Xaa Xaa Leu Xaa Xaa Cys Xaa Pro Xaa Xaa Thr 65 70 75 Ala Xaa Pro Xaa Arg Xaa Xaa Xaa Xaa Xaa Xaa Xaa Gly Asp Xaa 80 85 90 Xaa Xaa Phe Xaa Xaa Lys Leu Xaa Phe Xaa Xaa Xaa Xaa Leu Glu 95 100 105 Xaa Xaa Xaa Xaa Gin Gin [SEQ ID NO:21] 110 wherein Xaa at position 3 is Ser, Gly, Asp, Met, or Gin; Xaa at position 4 is Asn, His, or lie; Xaa at position 5 is Met or lie; Xaa at position 7 is Asp or Glu; Xaa at position 9 is He, Ala, Leu, or Gly; Xaa at position 10 is He, Val, or Leu; Xaa at position 11 is Thr, His, Gin, or Ala; Xaa at position 12 is His or Ala; Xaa at position 15 is Gin, Asn, or Val; Xaa at position 16 is Pro, Gly, or Gin; Xaa at position 17 is Pro, Asp, Gly, or Gin; Xaa at position 18 is Leu, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 19 is Pro or Glu; Xaa at position 20 is Leu, Val, Gly, Ser, Lys, Ala, Arg, Gin, Glu, He, Phe, Thr or Met; Xaa at position 21 is Leu, Ala, Asn, Pro, Gin, or Val; Xaa at position 23 is Phe, Ser, Pro, or Trp; Xaa at position 24 is Asn or Ala; Xaa at position 28 is Gly, Asp, Ser, Cys, Ala, Asn, He, Leu, Met Tyr or Arg; Xaa at position 30 is Asp or Glu; Xaa at position 31 is Gin, Val, Met, Leu, Thr, Ala, Asn, Glu, Ser or Lys; Xaa at position 32 is Asp, Phe, Ser, Thr, Ala, Asn, Gin, Glu, His, He, Lys, Tyr, Val or Cys; Xaa at position 36 is Glu, Ala, Asn, Ser or Asp; Xaa at position 37 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 40 is Arg or Ala; Xaa at position 41 is Arg, Thr, Val, Leu, or Gly; Xaa at position 42 is Pro, Gly, Ser, Gin, Ala, Arg, Asn, Glu, Leu, Thr, Val Lys; Xaa at position 46 is Ala or Ser; Xaa at position 48 is Asn, Pro, Thr, or lie; Xaa at position 49 is Arg or Lys; Xaa at position 50 is Ala or Asn; Xaa at position 51 is Val or Thr; Xaa at position 52 is Lys or Arg; Xaa at position 53 is Ser, Phe, or His; Xaa at position 54 is Leu, He, Phe, or His; Xaa at position 55 is Gin, Ala, Pro, Thr, Glu, Arg, or Gly; Xaa at position 57 is Ala, Pro, or Arg; Xaa at position 58 is Ser, Glu, Arg, or Asp; Xaa at position 59 is Ala or Leu; Xaa at position 62 is Ser, Val, Ala, Asn, Glu, Pro, or Gly; Xaa at position 63 is He or Leu; Xaa at position 65 is Lys, Thr, Gly, Asn, Met, Arg, He, Gly, or Asp; Xaa at position 66 is Asn, Gly, Glu, or Arg; Xaa at position 68 is Leu, Gin, Trp, Arg, Asp, Ala, Asn, Glu, His, He, Met, Phe, Ser, Thr, Tyr or Val; Xaa at position 69 is Pro or Thr; Xaa at position 71 is Leu or Val; Xaa at position 73 is Leu or Ser; Xaa at position 74 is Ala or Trp; Xaa at position 77 is Ala or Pro; Xaa at position 79 is Thr, Asp, Ser, Pro, Ala, Leu, or Arg; Xaa at position 81 is His, Pro, Arg, Val, Leu, Gly, Asn, Phe, Ser or Thr; Xaa at position 82 is Pro or Tyr; Xaa at position 83 is He or Val; Xaa at position 84 is His, He, Asn, Leu, Ala, Thr, Leu, Arg, Gin, Leu, Lys, Met, Ser, Tyr, Val or Pro; Xaa at position 85 is He, Leu, or Val; Xaa at position 86 is Lys, Arg, He, Gin, Pro, or Ser; Xaa at position 87 is Asp, Pro, Met, Lys, His, Thr, Asn, He, Leu or Tyr; Xaa at position 90 is Trp or Leu; Xaa at position 91 is Asn, Pro, Ala, Ser, Trp, Gin, Tyr, Leu, Lys, He, Asp, or His; Xaa at position 92 is Glu, or Gly; Xaa at position 94 is Arg, Ala, or Ser; Xaa at position 95 is Arg, Thr, Glu, Leu, or Ser; Xaa at position 98 is Thr, Val, or Gin; Xaa at position 100 is Tyr or Trp; Xaa at position 101 is Leu or Ala; Xaa at position 102 is Lys, Thr, Val, Trp, Ser, Ala, His, Met, Phe, Tyr or lie; Xaa at position 103 is Thr or Ser; Xaa at position 106 is Asn, Pro, Leu, His, Val, or Gin; Xaa at position 107 is Ala, Ser, He, Asn, Pro, Asp, or Gly; Xaa at position 108 is Gin, Ser, Met, Trp, Arg, Phe, Pro, His, He, Tyr, or Cys; Xaa at position 109 is Ala, Met, Glu, His, Ser, Pro, Tyr, or Leu; which can additionally have Met- or Met-Ala- preceding the amino acid in position 1; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native human interleukin-3. 7. The composition of 6, wherein said human interleukin-3 mutant polypeptide is of the Formula: Asn Cys Xaa Xaa Met He Asp Glu Xaa He Xaa Xaa Leu Lys Xaa 1 5 10 15 Xaa Pro Xaa Pro Xaa Xaa Asp Phe Xaa Asn Leu Asn Xaa Glu Asp 20 25 30 Xaa Xaa He Leu Met Xaa Xaa Asn Leu Arg Xaa Xaa Asn Leu Glu 35 40 45 Ala Phe Xaa Arg Xaa Xaa Lys Xaa Xaa Xaa Asn Ala Ser Ala He 50 55 60 Glu Xaa Xaa Leu Xaa Xaa Leu Xaa Pro Cys Leu Pro Xaa Xaa Thr 65 70 75 Ala Xaa Pro Xaa Arg Xaa Pro He Xaa Xaa Xaa Xaa Gly Asp Trp 80 85 90 Xaa Glu Phe Xaa Xaa Lys Leu Xaa Phe Tyr Leu Xaa Xaa Leu Glu 95 100 105 Xaa Xaa Xaa Xaa Gin Gin [SEQ ID NO:22] 110 wherein Xaa at position 3 is Ser, Gly, Asp, or Gin; Xaa at position 4 is Asn, His, or lie; Xaa at position 9 is He, Ala, Leu, or Gly; Xaa at position 11 is Thr, His, or Gin; Xaa at position 12 is His or Ala; Xaa at position 15 is Gin or Asn; Xaa at position 16 is Pro or Gly; Xaa at position 18 is Leu, Arg, Asn, or Ala; Xaa at position 20 is Leu, Val, Ser, Ala, Arg, Gin, Glu, He, Phe, Thr or Met; Xaa at position 21 is Leu, Ala, Asn, or Pro; Xaa at position 24 is Asn or Ala; Xaa at position 28 is Gly, Asp, Ser, Ala, Asn, He, Leu, Met, Tyr or Arg; Xaa at position 31 is Gin, Val, Met, Leu, Ala, Asn, Glu or Lys; Xaa at position 32 is Asp, Phe, Ser, Ala, Gin, Glu, His, Val or Thr; Xaa at position 36 is Glu, Asn, Ser or Asp; Xaa at position 37 is Asn, Arg, Pro, Thr, or His; Xaa at position 41 is Arg, Leu, or Gly; Xaa at position 42 is Pro, Gly, Ser, Ala, Asn, Val, Leu or Gin; Xaa at position 48 is Asn, Pro, or Thr; Xaa at position 50 is Ala or Asn; Xaa at position 51 is Val or Thr; Xaa at position 53 is Ser or Phe; Xaa at position 54 is Leu or Phe; Xaa at position 55 is Gin, Ala, Glu, or Arg; Xaa at position 62 is Ser, Val, Asn, Pro, or Gly; Xaa at position 63 is He or Leu; Xaa at position 65 is Lys, Asn, Met, Arg, He, or Gly; Xaa at position 66 is Asn, Gly, Glu, or Arg; Xaa at position 68 is Leu, Gin, Trp, Arg, Asp, Asn, Glu, His, Met, Phe, Ser, Thr, Tyr or Val; Xaa at position 73 is Leu or Ser; Xaa at position 74 is Ala or Trp; Xaa at position 77 is Ala or Pro; Xaa at position 79 is Thr, Asp, or Ala; Xaa at position 81 is His, Pro, Arg, Val, Gly, Asn, Ser or Thr; Xaa at position 84 is His, He, Asn, Ala, Thr, Arg, Gin, Glu, Lys, Met, Ser, Tyr, Val or Leu; Xaa at position 85 is He or Leu; Xaa at position 86 is Lys or Arg; Xaa at position 87 is Asp, Pro, Met, Lys, His, Pro, Asn, He, Leu or Tyr; Xaa at position 91 is Asn, Pro, Ser, He or Asp; Xaa at position 94 is Arg, Ala, or Ser; Xaa at position 95 is Arg, Thr, Glu, Leu, or Ser ; Xaa at position 98 is Thr or Gin; Xaa at position 102 is Lys , Val , Trp, or lie ; Xaa at position 103 is Thr, Ala, His , Phe , Tyr or Ser ; Xaa at position 106 is Asn, Pro, Leu, His , Val , or Gin; Xaa at position 107 is Ala, Ser, He , Pro, or Asp; Xaa at position 108 is Gin, Met , Trp, Phe , Pro, His , He , or Tyr; Xaa at position 109 is Ala, Met , Glu, Ser, or Leu; and which can additionally have Met- or Met-Ala- preceding the amino acid in position 1 ; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native ( 1-133 ) human interleukin-3 . 8. The composition of 7 , wherein said human interleukin-3 mutant polypeptide is of the Formula: Xaa at position 17 is Ser, Lys, Asp, Met, Gin, or Arg; Xaa at position 18 is Asn, His, Leu, He, Phe, Arg, or Gin; Xaa at position 19 is Met, Arg, Gly, Ala, or Cys; Xaa at position 20 is He, Cys, Gin, Glu, Arg, Pro, or Ala; Xaa at position 21 is Asp, Phe, Lys, Arg, Ala, Gly, or Val; Xaa at position 22 is Glu, Trp, Pro, Ser, Ala, His, or Gly; Xaa at position 23 is He, Ala, Gly, Trp, Lys, Leu, Ser, or Arg; Xaa at position 24 is He, Gly, Arg, or Ser; Xaa at position 25 is Thr, His, Gly, Gin, Arg, Pro, or Al ; Xaa at position 26 is His, Thr, Phe, Gly, Ala, or Trp; Xaa at position 27 is Leu, Gly, Arg, Thr, Ser, or Ala; Xaa at position 28 is Lys, Leu, Gin, Gly, Pro, Val or Trp; Xaa at position 29 is Gin, Asn, Pro, Arg, or Val; Xaa at position 30 is Pro, His, Thr, Gly, Asp, Gin, Ser, Leu, or Lys; Xaa at position 31 is Pro, Asp, Gly, Arg, Leu, or Gin; Xaa at position 32 is Leu, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 33 is Pro, Leu, Gin, Thr, or Glu; Xaa at position 34 is Leu, Gly, Ser, or Lys; Xaa at position 35 is Leu, Ala, Gly, Asn, Pro, or Gin; Xaa at position 36 is Asp, Leu, or Val; Xaa at position 37 is Phe, Ser, or Pro; Xaa at position 38 is Asn, or Ala; Xaa at position 40 is Leu, Trp, or Arg; Xaa at position 41 is Asn, Cys, Arg, Leu, His, Met, Pro; Xaa at position 42 is Gly, Asp, Ser, Cys, or Ala; Xaa at position 42 is Glu, Asn, Tyr, Leu, Phe, Asp, Ala, Cys, or Ser; Xaa at position 44 is Asp, Ser, Leu, Arg, Lys, Thr, Met, Trp, or Pro; Xaa at position 45 is Gin, Pro, Phe, Val, Met, Leu, Thr, Lys, or Trp; Xaa at position 46 is Asp, Phe, Ser, Thr, Cys, or Gly; Xaa at position 47 is He, Gly, Ser, Arg, Pro, or His; Xaa at position 48 is Leu, Ser, Cys, Arg, His, Phe, or Asn; Xaa at position 49 is Met, Arg, Ala, Gly, Pro, Asn, His, or Asp; Xaa at position 50 is Glu, Leu, Thr, Asp, or Tyr; Xaa at position 51 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 52 is Asn, His, Arg, Leu, Gly, Ser, or Thr; Xaa at position 53 is Leu, Thr, Ala, Gly, Glu, Pro, Lys, Ser, or; Xaa at position 54 is Arg, Asp, He, Ser, Val, Thr, Gin, or Leu; Xaa at position 55 is Arg, Thr, Val, Ser, Leu, or Gly; Xaa at position 56 is Pro, Gly, Cys, Ser, Gin, or Lys; Xaa at position 57 is Asn or Gly; Xaa at position 58 is Leu, Ser, Asp, Arg, Gin, Val, or Cys; Xaa at position 59 is Glu Tyr, His, Leu, Pro, or Arg; Xaa at position 60 is Ala, Ser, Tyr, Asn, or Thr; Xaa at position 61 is Phe, Asn, Glu, Pro, Lys, Arg, or Ser; Xaa at position 62 is Asn His, Val, Arg, Pro, Thr, or lie; Xaa at position 63 is Arg, Tyr, Trp, Ser, Pro, or Val; Xaa at position 64 is Ala, Asn, Ser, or Lys; Xaa at position 65 is Val, Thr, Pro, His, Leu, Phe, or Ser; Xaa at position 66 is Lys, He, Val, Asn, Glu, or Ser; Xaa at position 67 is Ser, Ala, Phe, Val, Gly, Asn, He, Pro, or His; Xaa at position 68 is Leu, Val, Trp, Ser, Thr, or His; Xaa at position 69 is Gin, Ala, Pro, Thr, Arg, Trp, Gly, or Leu; Xaa at position 70 is Asn, Leu, Val, Trp, Pro, or Ala; Xaa at position 71 is Ala, Met, Leu, Arg, Glu, Thr, Gin, Trp, or Asn; Xaa at position 72 is Ser, Glu, Met, Ala, His, Asn, Arg, or Asp; Xaa at position 73 is Ala, Glu, Asp, Leu, Ser, Gly, Thr, or Arg; Xaa at position 74 is He, Thr, Pro, Arg, Gly, Ala; Xaa at position 75 is Glu, Lys, Gly, Asp, Pro, Trp, Arg, Ser, or Leu; Xaa at position 76 is Ser, Val, Ala, Asn, Trp, Glu, Pro, Gly, or Asp; Xaa at position 77 is He, Ser, Arg, or Thr; Xaa at position 78 is Leu, Ala, Ser, Glu, Gly, or Arg; Xaa at position 79 is Lys, Thr, Gly, Asn, Met, He, or Asp; Xaa at position 80 is Asn, Trp, Val, Gly, Thr, Leu, or Arg; Xaa at position 81 is Leu, Gin, Gly, Ala, Trp, Arg, or Lys; Xaa at position 82 is Leu, Gin, Lys, Trp, Arg, or Asp; Xaa at position 83 is Pro, Thr, Trp, Arg, or Met; Xaa at position 84 is Cys, Glu, Gly, Arg, Met, or Val; Xaa at position 85 is Leu, Asn, or Gin; Xaa at position 86 is Pro, Cys, Arg, Ala, or Lys; Xaa at position 87 is Leu, Ser, Trp, or Gly; Xaa at position 88 is Ala, Lys, Arg, Val, or Trp; Xaa at position 89 is Thr, Asp, Cys, Leu, Val, Glu, His, or Asn; Xaa at position 90 is Ala, Ser, Asp, He, or Met; Xaa at position 91 is Ala, Ser, Thr, Phe, Leu, Asp, or His; Xaa at position 92 is Pro, Phe, Arg, Ser, Lys, His, or Leu; Xaa at position 93 is Thr, Asp, Ser, Asn, Pro, Ala, Leu, or Arg; Xaa at position 94 is Arg, He, Ser, Glu, Leu, Val, or Pro; Xaa at position 95 is His, Gin, Pro, Val, Leu, Thr or Tyr; Xaa at position 96 is Pro, Lys, Tyr, Gly, He, or Thr; Xaa at position 97 is He, Lys, Ala, or Asn; Xaa at position 98 is His, He, Asn, Leu, Asp, Ala, Thr, or Pro; Xaa at position 99 is He, Arg, Asp, Pro, Gin, Gly, Phe, or His; Xaa at position 100 is Lys, Tyr, Leu, His, He, Ser, Gin, or Pro; Xaa at position 101 is Asp, Pro, Met, Lys, His, Thr, Val, Tyr, or Gin; Xaa at position 102 is Gly, Leu, Glu, Lys, Ser, Tyr, or Pro; Xaa at position 103 is Asp, or Ser; Xaa at position 104 is Trp, Val, Cys, Tyr, Thr, Met, Pro, Leu, Gin, Lys, Ala, Phe, or Gly; Xaa at position 105 is Asn, Pro, Ala, Phe, Ser, Trp, Gin, Tyr, Leu, Lys, He, or His; Xaa at position 106 is Glu, Ser, Ala, Lys, Thr, He, Gly, or Pro; Xaa at position 108 is Arg, Asp, Leu, Thr, He, or Pro; Xaa at position 109 is Arg, Thr, Pro, Glu, Tyr, Leu, Ser, or Gly. 9. A composition of 8, wherein said human interleukin-3 mutant polypeptide is of the Formula: 1 5 10 (Met) m -Ala Pro Met Thr Gin Thr Thr Ser Leu Lys Thr 15 20 Ser Trp Val Asn Cys Ser Xaa Xaa Xaa Asp Glu He He 25 30 35 Xaa His Leu Lys Xaa Pro Pro Xaa Pro Xaa Leu Asp Xaa 40 45 50 Xaa Asn Leu Asn Xaa Glu Asp Xaa Asp He Leu Xaa Glu 55 60 Xaa Asn Leu Arg Xaa Xaa Asn Leu Xaa Xaa Phe Xaa Xaa 65 70 75 Ala Xaa Lys Xaa Leu Xaa Asn Ala Ser Xaa He Glu Xaa 80 85 He Leu Xaa Asn Leu Xaa Pro Cys Xaa Pro Xaa Xaa Thr 90 95 100 Ala Xaa Pro Xaa Arg Xaa Pro He Xaa He Xaa Xaa Gly 105 110 115 Asp Trp Xaa Glu Phe Arg Xaa Lys Leu Xaa Phe Tyr Leu 120 125 Xaa Xaa Leu Glu Xaa Ala Gin Xaa Gin Gin Thr Thr Leu 130 Ser Leu Ala He Phe [SEQ ID NO:129] wherein m is 0 or 1; Xaa at position 18 is Asn or He; Xaa at position 19 is Met, Ala or He; Xaa at position 20 is He, Pro or He; Xaa at position 23 is He, Ala or Leu; Xaa at position 25 is Thr or His; Xaa at position 29 is Gin, Arg, Val or lie; Xaa at position 32 is Leu, Ala, Asn or Arg; Xaa at position 34 is Leu or Ser; Xaa at position 37 is Phe, Pro, or Ser; Xaa at position 38 is Asn or Ala; Xaa at position 42 is Gly, Ala, Ser, Asp or Asn; Xaa at position 45 is Gin, Val, or Met; Xaa at position 46 is Asp or Ser; Xaa at position 49 is Met, He, Leu or Asp; Xaa at position 50 is Glu or Asp; Xaa at position 51 is Asn Arg or Ser; Xaa at position 55 is Arg, Leu, or Thr; Xaa at position 56 is Pro or Ser; Xaa at position 59 is Glu or Leu; Xaa at position 60 is Ala or Ser; Xaa at position 62 is Asn, Val or Pro; Xaa at position 63 is Arg or His; Xaa at position 65 is Val or Ser; Xaa at position 67 is Ser, Asn, His or Gin; Xaa at position 69 is Gin or Glu; Xaa at position 73 is Ala or Gly; Xaa at position 76 is Ser, Ala or Pro; Xaa at position 79 is Lys, Arg or Ser; Xaa at position 82 is Leu, Glu, Val or Trp; Xaa at position 85 is Leu or Val; Xaa at position 87 is Leu, Ser, Tyr; Xaa at position 88 is Ala or Trp; Xaa at position 91 is Ala or Pro; Xaa at position 93 is Pro or Ser; Xaa at position 95 is His or Thr; Xaa at position 98 is His, He, or Thr; Xaa at position 100 is Lys or Arg; Xaa at position 101 is Asp, Ala or Met; Xaa at position 105 is Asn or Glu; Xaa at position 109 is Arg, Glu or Leu; Xaa at position 112 is Thr or Gin; Xaa at position 116 is Lys, Val, Trp or Ser; Xaa at position 117 is Thr or Ser; Xaa at position 120 is Asn, Gin, or His; Xaa at position 123 is Ala or Glu; with the proviso that from one to three of the amino acids designated by Xaa are different from the corresponding amino acids of native human interleukin-3. 10. The composition of 9, wherein said human interleukin-3 mutant polypeptide is of the Formula: 1 5 10 (Met m -Ala n )p-Asn Cys Ser Xaa Xaa Xaa Asp Glu Xaa He 15 20 Xaa His Leu Lys Xaa Pro Pro Xaa Pro Xaa Leu Asp Xaa 25 30 35 Xaa Asn Leu Asn Xaa Glu Asp Xaa Xaa He Leu Xaa Glu 40 45 Xaa Asn Leu Arg Xaa Xaa Asn Leu Xaa Xaa Phe Xaa Xaa 50 55 60 Ala Xaa Lys Xaa Leu Xaa Asn Ala Ser Xaa He Glu Xaa 65 70 75 He Leu Xaa Asn Xaa Xaa Pro Cys Xaa Pro Xaa Ala Thr 80 85 Ala Xaa Pro Xaa Arg Xaa Pro He Xaa He Xaa Xaa Gly 90 95 100 Asp Trp Xaa Glu Phe Arg Xaa Lys Leu Xaa Phe Tyr Leu 105 110 Xaa Xaa Leu Glu Xaa Ala Gin Xaa Gin Gin [SEQ ID NO:130] wherein m is 0 or 1; n is 0 or 1; p is 0 or 1; Xaa at position 4 is Asn or He; Xaa at position 5 is Met, Ala or He: Xaa at position 6 is He, Pro or Leu; Xaa at position 9 is He, Ala or Leu; Xaa at position 11 is Thr or His; Xaa at position 15 is Gin, Arg, Val or He; Xaa at position 18 is Leu, Ala, Asn or Arg; Xaa at position 20 is Leu or Ser; Xaa at position 23 is Phe, Pro, or Ser; Xaa at position 24 is Asn or Ala; Xaa at position 28 is Gly, Ala, Ser, Asp or Asn; Xaa at position 31 is Gin, Val, or Met; Xaa at position 32 is Asp or Ser; Xaa at position 35 is Met, He or Asp; Xaa at position 36 is Glu or Asp; Xaa at position 37 is Asn, Arg or Ser; Xaa at position 41 is Arg, Leu, or Thr; Xaa at position 42 is Pro or Ser; Xaa at position 45 is Glu or Leu; Xaa at position 46 is Ala or Ser; Xaa at position 48 is Asn, Val or Pro; Xaa at position 49 is Arg or His; Xaa at position 51 is Val or Ser; Xaa at position 53 is Ser, Asn, His or Gin; Xaa at position 55 is Gin or Glu; Xaa at position 59 is Ala or Gly; Xaa at position 62 is Ser, Ala or Pro; Xaa at position 65 is Lys, Arg or Ser; Xaa at position 67 is Leu, Glu, or Val; Xaa at position 68 is Leu, Glu, Val or Trp; Xaa at position 71 is Leu or Val; Xaa at position 73 is Leu, Ser or Tyr; Xaa at position 74 is Ala or Trp; Xaa at position 77 is Ala or Pro; Xaa at position 79 is Pro or Ser; Xaa at position 81 is His or Thr; Xaa at position 84 is His, He, or Thr; Xaa at position 86 is Lys or Arg; Xaa at position 87 is Asp, Ala or Met; Xaa at position 91 is Asn or Glu; Xaa at position 95 is Arg, Glu, Leu; Xaa at position 98 Thr or Gin; Xaa at position 102 is Lys, Val, Trp or Ser; Xaa at position 103 is Thr or Ser; Xaa at position 106 is Asn, Gin, or His; Xaa at position 109 is Ala or Glu; with the proviso that from one to three of the amino acids designated by Xaa are different from the corresponding amino acids of native (15- 125)human interleukin-3. Also included in the present invention is a method of increasing multi-lineage hematopoietic cell production in a mammal in need thereof comprising administering a pharmaceutically effective amount of a human interleukin-3 mutant polypeptide as disclosed above with CSF, preferably G-CSF or GM-CSF simultaneously as a composition or one after the other. Materials and methods for IL-3 variant Expression in E.coli Unless noted otherwise, all specialty chemicals were obtained from Sigma Co., (St. Louis, MO) . Restriction endonucleases, T4 poly-nucleotides kinase, E. coli DNA polymerase I large fragment (Klenow) and T4 DNA ligase were obtained from New England Biolabs (Beverly, Massachusetts) . Escherichia coli strains Strain JM101: delta (pro lac), supE, thi, F' (traD36, rpoAB, lacI-Q, lacZdeltaM15) (Messing, 1979). This strain can be obtained from the American Type Culture Collection (ATCC) , 12301 Parklawn Drive, Rockville, Maryland 20852, accession number 33876. MON 105 (W3110 rpoH358) is a derivative of 3110 (Bachmann, 1972) and has been assigned ATCC accession number 55204. Strain GM48: dam-3, dcm-6, gal, ara, lac, thr, leu, tonA, tsx (Marinus, 1973) was used to make plasmid DNA that is not methylated at the sequence GATC. Genes and plasmids The gene used for hIL-3 production in E. coli was obtained from British Biotechnology Incorporated, Cambridge, England, catalogue number BBG14. This gene is carried on a pUC based plasmid designated pP0518. Many other human CSF genes can be obtained from R&D Systems, Inc. (Minn, MN) including IL-1 alpha, IL-1 beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, G-CSF, GM-CSF and LIF. The plasmids used for production of hIL-3 in E. coli contain genetic elements whose use has been described (Olins et al., 1988; Olins and Rangwala, 1990) . The replicon used is that of pBR327 (Covarrubias, et al., 1981) which is maintained at a copy number of about 100 in the cell (Soberon et al. , 1980) . A gene encoding the beta-lactamase protein is present on the plasmids. This protein confers ampicillin resistance on the cell. This resistance serves as a selectable phenotype for the presence of the plasmid in the cell. For cytoplasmic expression vectors the transcription promoter is derived from the recA gene of __. coli (Sancar et al. , 1980) . This promoter, designated precA, includes the RNA polymerase binding site and the lexA repressor binding site (the operator) . This segment of DNA provides high level transcription that is regulated even when the recA promoter is on a plasmid with the pBR327 origin of replication (Olins et al., 1988) incorporated herein by reference. The ribosome binding site used is that from gene 10 of phage T7 (Olins et al., 1988) . This is encoded in a 100 base pair (bp) fragment placed adjacent to precA. In the plasmids used herein, the recognition sequence for the enzyme Ncol (CCATGG) follows the glO-L. It is at this Ncol site that the hIL-3 genes were joined to the plasmid. It is expected that the nucleotide sequence at this junction will be recognized in mRNA as a functional start site for translation (Olins et al. , 1988) . The hIL-3 genes used were engineered to have a Hindlll recognition site (AAGCTT) downstream from the coding sequence of the gene. At this Hindlll site is a 514 base pair Rsal fragment containing the origin of replication of the single stranded phage fl (Dente et al., 1983; Olins, et al. , 1990) both incorporated herein by reference. A plasmid containing these elements is pMON2341. Another plasmid containing these elements is pMON5847 which has been deposited at the American Type Culture Collection, 12301 Parklawn Drive, Rockville, Maryland 20852 under the accession number ATCC 68912. In secretion expression plasmids the transcription promoter is derived from the ara B, A, and D genes of E.coli (Greenfield et al. , 1978) . This promoter is designated pAraBAD and is contained on a 323 base pair SacII, Bglll restriction fragment. The La B secretion leader (Wong et al., 1988, Clement et al., 1981) is fused to the N-terminus of the hIL-3 gene at the recognition sequence for the enzyme Ncol (5 'CCATGG3 ' ) . The hIL-3 genes used were engineered to have a Hindlll recognition site (5ΑAGCTT3 1 ) following the coding sequence of the gene. Recombinant DNA methods Synthetic σene assembly The hIL-3 variant genes and other CSF genes can be constructed by the assembly of synthetic oligonucleotides. Synthetic oligonucleotides were designed so that they would anneal in complementary pairs, with protruding single stranded ends, and when the pairs were properly assembled would result in a DNA sequence that encoded a portion of the desired gene. Amino acid substitutions in the hIL-3 gene were made by designing the oligonucleotides to encode the desired substitutions. The complementary oligonucleotides were annealed at concentration of 1 picomole per microliter in ligation buffer plus 50mM NaCl. The samples were heated in a 100 ml beaker of boiling water and permitted to cool slowly to room temperature. One picomole of each of the annealed pairs of oligonucleotides were ligated with approximately 0.2 picomoles of plasmid DNA, digested with the appropriate restriction enzymes, in ligation buffer (25 mM Tris pH 8.0, 10 mM MgCl2, 10 mM dithiothreitol, 1 mM ATP, 2mM spermidine) with T4 DNA ligase obtained from New England Biolabs (Beverly, Massachusetts) in a total volume of 20 μl at room temperature overnight. Polymerase Chain Reaction Polymerase Chain Reaction (hereafter referred to as PCR) techniques (Saiki, 1985) used the reagent kit and thermal cycler from Perkin-Elmer Cetus (Norwalk, CT. ) . PCR is based on a thermostable DNA polymerase from Thermus a uaticus. The PCR technique is a DNA amplification method that mimics the natural DNA replication process in that the number of DNA molecules doubles after each cycle, in a way similar to in vivo replication. The DNA polymerase mediated extension is in a 5' to 3 ' direction. The term "primer" as used herein refers to an oligonucleotide sequence that provides an end to which the DNA polymerase can add nucleotides that were complementary to a nucleotide sequence. The latter nucleotide sequence is referred to as the "template", to which the primers were annealed. The amplified PCR product is defined as the region comprised between the 5' ends of the extension primers. Since the primers have defined sequences, the product will have discrete ends, corresponding to the primer sequences. The primer extension reaction is carried out using 20 picomoles (pmoles) of each of the oligonucleotides and 1 picogram of template plasmid DNA for 35 cycles (1 cycle is defined as 94 degrees C for one minute, 50 degrees C for two minutes and 72 degrees for three minutes.) . The reaction mixture was extracted with an equal volume of phenol/chloroform (50% phenol and 50% chloroform, volume to volume) to remove proteins. The aqueous phase, containing the amplified DNA, and solvent phase were separated by centrifugation for 5 minutes in a microcentrifuge (Model 5414 Eppendorf Inc, Fremont CA. ) . To precipitate the amplified DNA the aqueous phase was removed and transferred to a fresh tube to which was added 1/10 volume of 3M NaOAc (pH 5.2) and 2.5 volumes of ethanol (100% stored at minus 20 degrees C) . The solution was mixed and placed on dry ice for 20 minutes. The DNA was pelleted by centrifugation for 10 minutes in a microcentrifuge and the solution was removed from the pellet. The DNA pellet was washed with 70% ethanol, ethanol removed and dried in a speedvac concentrator (Savant, Farmingdale, New York) . The pellet was resuspended in 25 microliters of TE (20mM Tris-HCl pH 7.9, IrriM EDTA) . Alternatively the DNA was precipitated by adding equal volume of 4M NH4OAC and one volume of isopropanol [Treco et al . , (1988)] . The solution was mixed and incubated at room temperature for 10 minutes and centrifuged. These conditions selectively precipitate DNA fragments larger than - 20 bases and were used to remove oligonucleotide primers. One quarter of the reaction was digested with restriction enzymes [Higuchi, (1989)] an on completion heated to 70 degrees C to inactivate the enzymes. Recovery of recombinant plasmids from liσation mixes E. coli JM101 cells were made competent to take up DNA. Typically, 20 to 100 ml of cells were grown in LB medium to a density of approximately 150 Klett units and then collected by centrifugation. The cells were resuspended in one half culture volume of 50 mM CaCl2 and held at 4°C for one hour. The cells were again collected by centrifugation and resuspended in one tenth culture volume of 50 mM CaCl2. DNA was added to a 150 microliter volume of these cells, and the samples were held at 4°C for 30 minutes. The samples were shifted to 42°C for one minute, one milliliter of LB was added, and the samples were shaken at 37°C for one hour. Cells from these samples were spread on plates containing ampicillin to select for transformants. The plates were incubated overnight at 37°C. Single colonies were picked, grown in LB supplemented with ampicillin overnight at 37°C with shaking. From these cultures DNA was isolated for restriction analysis. Culture medium LB medium (Maniatis et al. , 1982) was used for growth of cells for DNA isolation. M9 minimal medium supplemented with 1.0% casamino acids, acid hydrolyzed casein, Difco (Detroit, Michigan) was used for cultures in which recombinant IL-3 variant was produced. The ingredients in the M9 medium were as follows: 3g/liter KH2P04, 6g/l Na2HP04, 0.5 g/1 NaCl, 1 g/1 NH4CI, 1.2 mM MgS04, 0.025 mM CaCl2, 0.2% glucose (0.2% glycerol with the AraBAD promoter), 1% casamino acids, 0.1 ml/1 trace minerals (per liter 108 g FeCl3-6H2θ, 4.0 g ZnSθ4-7H2θ, 7.0 CoCl2-2H2θ, 7.0 g a2Moθ4•2H20, 8.0 g CuSθ4-5H2θ, 2.0 g H3B03, 5.0 g MnSθ4-H2θ, 100 ml concentrated HCl) . Bacto agar was used for solid media and ampicillin was added to both liquid and solid LB media at 200 micrograms per milliliter. Production of IL-3 variants in E. coli with vectors employing the recA promoter __• coli strains harboring the plasmids of interest were grown at 37°C in M9 plus casamino acids medium with shaking in a Gyrotory water bath Model G76 from New Brunswick Scientific (Edison, New Jersey) . Growth was monitored with a Klett Summerson meter (green 54 filter) , Klett Mfg. Co. (New York, New York) . At a Klett value of approximately 150, an aliquot of the culture (usually one milliliter) was removed for protein analysis. To the remaining culture, nalidixic acid (lOmg/ml) in 0.1 N NaOH was added to a final concentration of 50 μg/ml. The cultures were shaken at 37°C for three to four hours after addition of nalidixic acid. A high degree of aeration was maintained throughout the bacterial growth in order to achieve maximal production of the desired gene product. The cells were examined under a light microscope for the presence of refractile bodies (RBs) . One milliliter aliquots of the culture were removed for analysis of protein content. Extraction. Refolding and Purification of IL-3 Variant Proteins Expressed as Refractile bodies in E. coli Extraction of refractile bodies (RB's) : For each gram of RB's (and typically one gram is obtained from a 300 ml E. coli culture) , 5 ml of a solution containing 6M guanidine hydrochloride (GnHCl), 50 mM 2-N-cyclohexylaminoethanesulfonic acid (CHES) pH 9.5 and 20 mM dithiothreitol (DTT) was added. The RB's were extracted with a Bio-Homogenizer for 15-30 seconds and gently rocked for 2 hours at 5 degrees centigrade (5°C) to allow the protein to completely reduce and denature. Refolding of the IL-3 muteins The protein solution was transferred to dialysis tubing (1000 molecular weight cut-off) and dialyzed against at least 100 volumes of 4M GnHCl - 50 mM CHES pH 8.0. The dialysis was continued overnight at 5°C while gently stirring. Subsequently dialysis was continued against at least 100 volumes of 2M GnHCl - 50 mM CHES pH 8.0 and dialyzed overnight at 5°C while gently stirring. Purification of the IL-3 muteins The protein solution was removed from the dialysis tubing and acidified by the addition of 40% acetonitrile (CH3CN) - 0.2% trifluoroacetic acid (TFA) to a final concentration of 20% CH3CN - 0.1% TFA. This was centrifuged (16,000 x g for 5 minutes) to clarify and the supernatant was loaded onto a Vydac C-18 reversed phase column (10x250 mm) available from Vydac (Hesperia, California) previously equilibrated in 20% CH3CN - 0.1% TFA. The column was eluted with a linear gradient (0.2% CH3CN/minute) between 40 - 50% CH3CN - 0.1% TFA at a flow rate of 3 ml/minute while collecting 1.5 ml fractions . The fractions were analyzed by polyacrylamide gel electrophoresis (SDS-PAGE) and the appropriate fractions pooled. The pooled material was dried by lyophilization or in a Speed Vac concentrator. The dry powder was reconstituted with 10 mM ammonium bicarbonate pH 7.5, centrifuged (16,000 x g for 5 minutes) to clarify and assayed for protein concentration by the method of Bradford (1976) with bovine serum albumin as the standard. Such protein can be further analyzed by additional techniques such as, SDS-PAGE, electrospray mass spectrometry, reverse phase HPLC, capillary zone electrophoresis, amino acid composition analysis, and ELISA (enzyme- linked immunosorbent assay) . hIL-3 SANDWICH ELISA The IL-3 variant protein concentrations can be determined using a sandwich ELISA based on an affinity purified polyclonal goat anti-rhIL-3. Microtiter plates (Dynatech Immulon II) were coated with 150 μl goat-anti-rhIL-3 at a concentration of approximately 1 μg/ml in 100 mM NaHC03, pH 8.2. Plates were incubated overnight at room temperature in a chamber maintaining 100% humidity. Wells were emptied and the remaining reactive sites on the plate were blocked with 200 μl of solution containing 10 mM PBS, 3% BSA and 0.05% Tween 20, pH 7.4 for 1 hour at 37° C and 100% humidity. Wells were emptied and washed 4X with 150 mM NaCl containing 0.05% Tween 20 (wash buffer) . Each well then receives 150 μl of dilution buffer (10 mM PBS containing 0.1% BSA, 0.01% Tween 20, pH 7.4), containing rhIL-3 standard, control, sample or dilution buffer alone. A standard curve was prepared with concentrations ranging from 0.125 ng/ml to 5 ng/ml using a stock solution of rhIL-3 (concentration determined by amino acid composition analysis) . Plates were incubated 2.5 hours at 37° C and 100% humidity. Wells were emptied and each plate was washed 4X with wash buffer. Each well then received 150 μl of an optimal dilution (as determined in a checkerboard assay format) of goat anti-rhIL-3 conjugated to horseradish peroxidase. Plates were incubated 1.5 hours at 37° C and 100% humidity. Wells were emptied and each plate was washed 4X with wash buffer. Each well then received 150 ul of ABTS substrate solution (Kirkegaard and Perry) . Plates were incubated at room temperature until the color of the standard wells containing 5 ng/ml rhIL-3 had developed enough to yield an absorbance between 0.5-1.0 when read at a test wavelength of 410 nm and a reference wavelength of 570 nm on a Dynatech microtiter plate reader. Concentrations of immunoreactive rhIL-3 in unknown samples were calculated from the standard curve using software supplied with the plate reader. AML Proliferation Assay for Bioactive Human Interleukin-3 The factor-dependent cell line AML 193 was obtained from the American Type Culture Collection (ATCC, Rockville, MD) . This cell line, established from a patient with acute myelogenous leukemia, was a growth factor dependent cell line which displayed enhanced growth in GM/CSF supplemented medium (Lange, B. , et al., (1987); Valtieri, M. , et al. , (1987) . The ability of AML 193 cells to proliferate in the presence of human IL-3 has also been documented. (Santoli, D. , et al. , (1987)) . A cell line variant was used, AML 193 1.3, which was adapted for long term growth in IL-3 by washing out the growth factors and starving the cytokine dependent AML 193 cells for growth factors for 24 hours. The cells were then replated at 1x105 cells/well in a 24 well plate in media containing 100 U/ml IL-3. It took approximately 2 months for the cells to grow rapidly in IL-3. These cells were maintained as AML 193 1.3 thereafter by supplementing tissue culture medium (see below) with human IL-3. AML 193 1.3 cells were washed 6 times in cold Hanks balanced salt solution (HBSS, Gibco, Grand Island, NY) by centrifuging cell suspensions at 250 x g for 10 minutes followed by decantation of supernatant. Pelleted cells were resuspended in HBSS and the procedure was repeated until six wash cycles were completed. Cell>. washed six times by this procedure were resuspended in tissue culture medium at a density ranging from 2 x 105 to 5 x 105 viable cells/ml. This medium was prepared by supplementing Iscove's modified Dulbecco ' s Medium (IMDM, Hazleton, Lenexa, KS) with albumin, transferrin, lipids and 2-mercaptoethanol. Bovine albumin (Boehringer-Mannheim, Indianapolis, IN) was added at 500 μg/ml; human transferrin (Boehringer- Mannheim, Indianapolis, IN) was added at 100 μg/ml; soybean lipid (Boehringer-Mannheim, Indianapolis, IN) was added at 50 μg/ml; and 2-mercaptoethanol (Sigma, St. Louis, MO) was added at 5 x 10" 5 . Serial dilutions of human interleukin-3 or human interleukin-3 variant protein (hIL-3 mutein) were made in triplicate series in tissue culture medium supplemented as stated above in 96 well Costar 3596 tissue culture plates. Each well contained 50 μl of medium containing interleukin-3 or interleukin-3 variant protein once serial dilutions were completed. Control wells contained tissue culture medium alone (negative control) . AML 193 1.3 cell suspensions prepared as above were added to each well by pipetting 50 μl (2.5 x 104 cells) into each well. Tissue culture plates were incubated at 37°C with 5% Cθ2 in humidified air for 3 days. On day 3, 0.5 μCi 3H-thymidine (2 Ci/mM, New England Nuclear, Boston, MA) was added in 50 μl of tissue culture medium. Cultures were incubated at 37°C with 5% C02 in humidified air for 18-24 hours. Cellular DNA was harvested onto glass filter mats (Pharmacia LKB, Gaithersburg, MD) using a TOMTEC cell harvester (TOMTEC, Orange, CT) which utilized a water wash cycle followed by a 70% ethanol wash cycle. Filter mats were allowed to air dry and then placed into sample bags to which scintillation fluid (Scintiverse II, Fisher Scientific, St. Louis, MO or BetaPlate Scintillation Fluid, Pharmacia LKB, Gaithersburg, MD) was added. Beta emissions of samples from individual tissue culture wells were counted in a LKB Betaplate model 1205 scintillation counter (Pharmacia LKB, Gaithersburg, MD) and data was expressed as counts per minute of 3H- thymidine incorporated into cells from each tissue culture well. Activity of each human interleukin-3 preparation or human interleukm-3 variant preparation was quantitated by measuring cell proliferation (3H- thymidine incorporation) induced by graded concentrations of interleukin-3 or interleukin-3 variant. Typically, concentration ranges from 0.05 pM - 105 pM were quantitated in these assays. Activity was determined by measuring the dose of interleukin-3 or interleukin-3 variant which provides 50% of maximal proliferation [EC50 = 0.5 x (maximum average counts per minute of H-thymidine incorporated per well among triplicate cultures of all concentrations of interleukin-3 tested - background proliferation measured by 3κ-thymidine incorporation observed in triplicate cultures lacking interleukin-3] . This EC50 value is also equivalent to 1 unit of bioactivity. Every assay was performed with native interleukin-3 as a reference standard so that relative activity levels could be assigned. Methylcellulose Assay This assay provides a reasonable approximation of the growth activity of colony stimulating factors to stimulate normal bone marrow cells to produce different types of hematopoietic colonies in vitro (Bradley et al., 1966, Pluznik et al. , 1965) . Methods Approximately 30 ml of fresh, normal, healthy bone marrow aspirate are obtained from individuals. Under sterile conditions samples are diluted 1:5 with a IXPBS (#14040.059 Life Technologies, Gaithersburg, MD. ) solution in a 50 ml conical tube (#25339-50 Corning, Corningn MD) . Ficoll (Histopaque-1077 Sigma H-8889) is layered under the diluted sample and centrifuged, 300 x g for 30 min. The mononuclear cell band is removed and washed two times in IXPBS and once with 1% BSA PBS (CellPro Co., Bothel, WA) . Mononuclear cells are counted and CD34+ cells are selected using the Ceprate LC (CD34) Kit (CellPro Co., Bothel, WA) column. This fractionation is performed since all stem and progenitor cells within the bone marrow display CD34 surface antigen. Alternatively whole bone marrow or peripheral blood may be used. Cultures are set up in triplicate wells with a final volume of 0.1 ml in 48 well tissue culture plates (#3548 CoStar, Cambridge, MA) . Culture medium is purchased from Terry Fox Labs. (HCC-4330 medium (Terry Fox Labs, Vancouver, B.C., Canada)) . 600-1000 CD34+cells are added per well. Native IL-3 and IL-3 variants are added to give final concentrations ranging from . OOlnM-lOnm. G-CSF and GM-CSF and C-Kit ligand are added at a final concentration of O.lnm. Native IL-3 and IL-3 variants are supplied in house. C-Kit Ligand (#255-CS), G-CSF (#214-CS) and GM-CSF (#215-GM) are purchased from R&D Systems (Minneapolis, MN) . Cultures are resuspended using an Eppendorf repeater and 0.1 ml is dispensed per well. Control (baseline response) cultures received no colony stimulating factors. Positive control cultures received conditioned media (PHA stimulated human cells:Terry Fox Lab. H2400) . Cultures are incubated at 37°C, 5% C02 in humidified air. Hematopoietic colonies which are defined as greater than 50 cells are counted on the day of peak response (days 10-11) using a Nikon inverted phase microscope with a 40x objective combination. Groups of cells containing fewer than 50 cells are referred to as clusters. Alternatively colonies can be identified by spreading the colonies on a slide and stained or they can be picked, resuspended and spun onto cytospin slides for staining. Human Cord Blood He opoietic Growth Factor Assays Bone marrow cells are traditionally used for in vitro assays of hematopoietic colony stimulating factor (CSF) activity. However, human bone marrow is not always available, and there is considerable variability between donors. Umbilical cord blood is comparable to bone marrow as a source of hematopoietic stem cells and progenitors (Broxmeyer et al. , 1992; Mayani et al. , 1993) . In contrast to bone marrow, cord blood is more readily available on a regular basis. There is also a potential to reduce assay variability by pooling cells obtained fresh from several donors, or to create a bank of cryopreserved cells for this purpose. By modifying the culture conditions, and/or analyzing for lineage specific markers, it should be possible to assay specifically for granulocyte / macrophage colonies (CFU-GM) , for megakaryocyte CSF activity, or for high proliferative potential colony forming cell (HPP-CFC) activity. METHODS Mononuclear cells (MNC) are isolated from cord blood within 24 hrs of collection, using a standard density gradient (1.077g/ml Histopaque) . Cord blood MNC have been further enriched for stem cells and progenitors by several procedures, including immunomagnetic selection for CD14-, CD34+ cells; panning for SBA-, CD34+ fraction using coated flasks from Applied Immune Science (Santa Clara, CA) ; and CD34+ selection using a CellPro (Bothell, WA) avidin column. Either freshly isolated or cryopreserved CD34+ cell enriched fractions are used for the assay. Duplicate cultures for each serial dilution of sample (concentration range from 1pm to 1204pm) are prepared with 1x104 cells in 1ml of .9% methocellulose containing medium without additional growth factors (Methocult H4230 from Stem Cell Technologies, Vancouver, BC.) . In some experiments, Methocult H4330 containing erythropoietin (EPO) was used instead of Methocult H4230, or Stem Cell Factor (SCF) , 50ng/ml (Biosource International, Camarillo, CA) was added. After culturing for 7-9 days, colonies containing >30 cells are counted. In order to rule out subjective bias in scoring, assays are scored blind. IL-3 mediated sulfidoleukotriene release from human mononuclear cells The following assay was used to measure IL-3 mediated sulfidoleukotriene release from human mononuclear cells. Heparin-containing human blood was collected and layered onto an equal volume of Ficoll-Paque (Pharmacia # 17-0840-02) ready to use medium (density 1.077 g/ml. ) . The Ficoll was warmed to room temperature prior to use and clear 50 ml polystyrene tubes were utilized. The Ficoll gradient was spun at 300 x g for 30 minutes at room temperature using a H1000B rotor in a Sorvall RT6000B refrigerated centrifuge. The band containing the mononuclear cells was carefully removed, the volume adjusted to 50 mis with Dulbecco' s phosphate-buffered saline (Gibco Laboratories cat. # 310-4040PK) , spun at 400 x g for 10 minutes at 4°C and the supernatant was carefully removed. The cell pellet was washed twice with HA Buffer [ 20 mM Hepes (Sigma # H- 3375), 125 mM NaCl (Fisher # S271-500), 5 mM KC1 (Sigma # P-9541) , 0.5 mM glucose (Sigma # G- 5000), 0.025% Human Serum Albumin (Calbiochem # 126654) and spun at 300 x g, 10 min., 4°C. The cells were resuspended in HACM Buffer (HA buffer supplemented with 1 mM CaC12 (Fisher # C79-500) and 1 mM MgC12 (Fisher # M-33) at a concentration of 1 x 106 cells/ml and 180 μl were transferred into each well of 96 well tissue culture plates. The cells were allowed to acclimate at 37°C for 15 minutes. The cells were primed by adding 10 μls of a 20 X stock of various concentrations of cytokine to each well (typically 100000, 20000, 4000, 800, 160, 32, 6.4, 1.28, 0 fM IL3) . The cells were incubated for 15 minutes at 37°C. Sulfidoleukotriene release was activated by the addition of 10 μls of 20 X (1000 nM) fmet-leu-phe (Calbiochem # 344252) final concentration 50nM FMLP and incubated for 10 minutes at 37°C. The plates were spun at 350 x g at 4°C for 20 minutes. The supernatants were removed and assayed for sulfidoleukotrienes using Cayman's Leukotriene C4 EIA kit (Cat. #420211) according to manufacturers' directions. Native (15-125)hIL-3 was run as a standard control in each assay. Further details of genetic engineering techniques known to those skilled in the art may be found in T. Maniatis, et al. , Molecular Cloning, A Laboratory Manual, Cold Spring Harbor Laboratory (1982) and references cited therein, incorporated herein by reference; and in J. Sambrook, et al. , Molecular Cloning, A Laboratory Manual, 2nd edition, Cold Spring Harbor Laboratory (1989) and references cited therein, incorporated herein by reference. Amino acids are shown herein by standard one letter or three letter abbreviations as follows: Abbreviated Designation Amino Acid A Ala Alanine C Cys Cysteine D Asp Aspartic acid E Glu Glutamic acid F Phe Phenylalanine Abbreviated Designation Amino Acid G Gly Glycine H His Histidine I He Isoleucine K Lys Lysine L Leu Leucine M Met Methionine N Asn Asparagine P Pro Proline Q Gin Glutamine R Arg Arginine S Ser Serine T Thr Threonine V Val Valine W Trp Tryptophan Y Tyr Tyrosine Compositions of the present invention comprise a therapeutically effective amount of one or more of the hIL-3 muteins of the present invention in a mixture with a pharmaceutically acceptable carrier with CSF. This composition can be administered either parenterally, intravenously or subcutaneously. When administered, the therapeutic composition for use in this invention is preferably in the form of a pyrogen-free, parenterally acceptable aqueous solution. The preparation of such a parenterally acceptable protein solution, having due regard to pH, isotonicity, stability and the like, is within the skill of the art. The dosage regimen involved in a method for treating the above-described conditions will be determined by the attending physician considering various factors which modify the action of drugs, e.g. the condition, body weight, sex and diet of the patient, the severity of any infection, time of administration and other clinical factors. Generally, a daily regimen may be in the range of 0.2 - 150 μg/kg of non-glycosylated IL-3 protein per kilogram of body weight and 0.2 - 150 μg/kg of CSFS per kilogram of body weight. This dosage regimen is referenced to a standard level of biological activity which recognizes that native IL-3 generally possesses an EC50 at or about 10 picoMolar to 100 picoMolar in the AML proliferation assay described herein. Therefore, dosages would be adjusted relative to the activity of a given mutein vs. the activity of native (reference) IL-3 and it would not be unreasonable to note that dosage regimens may include doses as low as 0.1 microgram and as high as 1 milligram per kilogram of body weight per day. As indicated above, the therapeutic method and compositions may also include co-administration with other human factors. A non-exclusive list of other appropriate hematopoietins, CSFs and interleukins for simultaneous or serial co-administration with the polypeptides of the present invention includes GM-CSF, CSF-1, G-CSF, Meg-CSF, M-CSF, erythropoietin (EPO), IL-1, IL-4, IL-2, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, LIF, B-cell growth factor, B-cell differentiation factor and eosinophil differentiation factor, stem cell factor (SCF) also known as steel factor or c- kit ligand, or combinations thereof. Progress of the treated patient can be monitored by periodic assessment of the hematological profile, e.g., differential cell count and the like. Additional details may be found in co-pending United States Patent Application Serial number PCT/US93/11198 which is hereby incorporated by reference in its entirety as if written herein. Additional details on how to make the compositions of the present invention can be found in WO 91/07988. Additional details about the CSFs and the variants thereof can be found in U.S. Patent 4,810,643, 5,218,092 and E.P. Application 02174004. All references, patents or applications cited herein are incorporated by reference in their entirety as if written herein. Various examples will be apparent to the person skilled in the art after reading the present disclosure without departing from the spirit and scope of the invention. It is intended that all such examples be included within the scope of the appended claims. 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Claims: WHAT IS CLAIMED IS: 1. A composition, comprising: A human interleukin-3 mutant polypeptide of the Formula: Ala Pro Met Thr Gin Thr Thr Ser Leu Lys Thr Ser Trp Val Asn 1 5 10 15 Cys Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 20 25 30 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Asn Xaa Xaa Xaa Xaa Xaa Xaa 35 40 45 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 50 55 60 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 65 70 75 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 80 85 90 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 95 100 105 Xaa Phe Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 110 115 120 Xaa Xaa Xaa Gin Gin Thr Thr Leu Ser Leu Ala lie Phe 125 130 [SEQ ID NO:15] wherein Xaa at position 17 is Ser, Lys, Gly, Asp, Met, Gin, or Arg; Xaa at position 18 is Asn, His, Leu, lie, Phe, Arg, or Gin; Xaa at position 19 is Met, Phe, lie, Arg, Gly, Ala, or Cys; Xaa at position 20 is lie, Cys, Gin, Glu, Arg, Pro, or Ala; Xaa at position 21 is Asp, Phe, Lys, Arg, Ala, Gly, Glu, Gin, Asn, Thr, Ser or Val; Xaa at position 22 is Glu, Trp, Pro, Ser, Ala, His, Asp, Asn, Gin, Leu, Val or Gly; Xaa at position 23 is lie, Val, Ala, Leu, Gly, Trp, Lys, Phe, Leu, Ser, or Arg; Xaa at position 24 is lie, Gly, Val, Arg, Ser, Phe, or Leu; Xaa at position 25 is Thr, His, Gly, Gin, Arg, Pro, or Ala; Xaa at position 26 is His, Thr, Phe, Gly, Arg, Ala, or Trp; Xaa at position 27 is Leu, Gly, Arg, Thr, Ser, or Ala; Xaa at position 28 is Lys, Arg, Leu, Gin, Gly, Pro, Val or Trp; Xaa at position 29 is Gin, Asn, Leu, Pro, Arg, or Val; Xaa at position 30 is Pro, His, Thr, Gly, Asp, Gin, Ser, Leu, or Lys; Xaa at position 31 is Pro, Asp, Gly, Ala, Arg, Leu, or Gin; Xaa at position 32 is Leu, Val, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 33 is Pro, Leu, Gin, Ala, Thr, or Glu; Xaa at position 34 is Leu, Val, Gly, Ser, Lys, Glu, Gin, Thr, Arg, Ala, Phe, lie or Met; Xaa at position 35 is Leu, Ala, Gly, Asn, Pro, Gin, or Val; Xaa at position 36 is Asp, Leu, or Val; Xaa at position 37 is Phe, Ser, Pro, Trp, or lie; Xaa at position 38 is Asn, or Ala; Xaa at position 40 is Leu, Trp, or Arg; Xaa at position 41 is Asn, Cys, Arg, Leu, His, Met, or Pro; Xaa at position 42 is Gly, Asp, Ser, Cys, Asn, Lys, Thr, Leu, Val, Glu, Phe, Tyr, lie, Met or Ala; Xaa at position 43 is Glu, Asn, Tyr, Leu, Phe, Asp, Ala, Cys, Gin, Arg, Thr, Gly or Ser; Xaa at position 44 is Asp, Ser, Leu, Arg, Lys, Thr, Met, Trp, Glu, Asn, Gin, Ala or Pro; Xaa at position 45 is Gin, Pro, Phe, Val, Met, Leu, Thr, Lys, Trp, Asp, Asn, Arg, Ser, Ala, lie, Glu or His; Xaa at position 46 is Asp, Phe, Ser, Thr, Cys, Glu, Asn, Gin, Lys, His, Ala, Tyr, lie, Val or Gly; Xaa at position 47 is lie, Gly, Val, Ser, Arg, Pro, or His; Xaa at position 48 is Leu, Ser, Cys, Arg, lie, His, Phe, Glu, Lys, Thr, Ala, Met, Val or Asn; Xaa at position 49 is Met, Arg, Ala, Gly, Pro, Asn, His, or Asp; Xaa at position 50 is Glu, Leu, Thr, Asp, Tyr, Lys, Asn, Ser, Ala, lie, Val, His, Phe, Met or Gin; Xaa at position 51 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 52 is Asn, His, Arg, Leu, Gly, Ser, or Thr; Xaa at position 53 is Leu, Thr, Ala, Gly, Glu, Pro, Lys, Ser, or Met; Xaa at position 54 is Arg, Asp, lie, Ser, Val, Thr, Gin, Asn, Lys, His, Ala or Leu; Xaa at position 55 is Arg, Thr, Val, Ser, Leu, or Gly; Xaa at position 56 is Pro, Gly, Cys, Ser, Gin, Glu, Arg, His, Thr, Ala, Tyr, Phe, Leu, Val or Lys; Xaa at position 57 is Asn or Gly; Xaa at position 58 is Leu, Ser, Asp, Arg, Gin, Val, or Cys; Xaa at position 59 is Glu Tyr, His, Leu, Pro, or Arg; Xaa at position 60 is Ala, Ser, Pro, Tyr, Asn, or Thr; Xaa at position 61 is Phe, Asn, Glu, Pro, Lys, Arg, or Ser; Xaa at position 62 is Asn His, Val, Arg, Pro, Thr, Asp, or lie; Xaa at position 63 is Arg, Tyr, Trp, Lys, Ser, His, Pro, or Val; Xaa at position 64 is Ala, Asn, Pro, Ser, or Lys; Xaa at position 65 is Val, Thr, Pro, His, Leu, Phe, or Ser; Xaa at position 66 is Lys, lie, Arg, Val, Asn, Glu, or Ser; Xaa at position 67 is Ser, Ala, Phe, Val, Gly, Asn, lie, Pro, or His; Xaa at position 68 is Leu, Val, Trp, Ser, lie, Phe, Thr, or His; Xaa at position 69 is Gin, Ala, Pro, Thr, Glu, Arg, Trp, Gly, or Leu; Xaa at position 70 is Asn, Leu, Val, Trp, Pro, or Ala; Xaa at position 71 is Ala, Met, Leu, Pro, Arg, Glu, Thr, Gin, Trp, or Asn; Xaa at position 72 is Ser, Glu, Met, Ala, His, Asn, Arg, or Asp; Xaa at position 73 is Ala, Glu, Asp, Leu, Ser, Gly, Thr, or Arg; Xaa at position 74 is lie, Met, Thr, Pro, Arg, Gly, Ala; Xaa at position 75 is Glu, Lys, Gly, Asp, Pro, Trp, Arg, Ser, Gin, or Leu; Xaa at position 76 is Ser, Val, Ala, Asn, Trp, Glu, Pro, Gly, or Asp; Xaa at position 77 is lie, Ser, Arg, Thr, or Leu; Xaa at position 78 is Leu, Ala, Ser, Glu, Phe, Gly, or Arg; Xaa at position 79 is Lys, Thr, Asn, Met, Arg, lie, Gly, or Asp; Xaa at position 80 is Asn, Trp, Val, Gly, Thr, Leu, Glu, or Arg; Xaa at position 81 is Leu, Gin, Gly, Ala, Trp, Arg, Val, or Lys; Xaa at position 82 is Leu, Gin, Lys, Trp, Arg, Asp, Glu, Asn, His, Thr, Ser, Ala, Tyr, Phe, lie, Met or Val; Xaa at position 83 is Pro, Ala, Thr, Trp, Arg, or Met; Xaa at position 84 is Cys, Glu, Gly, Arg, Met, or Val; Xaa at position 85 is Leu, Asn, Val, or Gin; Xaa at position 86 is Pro, Cys, Arg, Ala, or Lys; Xaa at position 87 is Leu, Ser, Trp, or Gly; Xaa at position 88 is Ala, Lys, Arg, Val, or Trp; Xaa at position 89 is Thr, Asp, Cys, Leu, Val, Glu, His, Asn, or Ser; Xaa at position 90 is Ala, Pro, Ser, Thr, Gly, Asp, lie, or Met; Xaa at position 91 is Ala, Pro, Ser, Thr, Phe, Leu, Asp, or His; Xaa at position 92 is Pro, Phe, Arg, Ser, Lys, His, Ala, Gly, lie or Leu; Xaa at position 93 is Thr, Asp, Ser, Asn, Pro, Ala, Leu, or Arg; Xaa at position 94 is Arg, lie, Ser, Glu, Leu, Val, Gin, Lys, His, Ala, or Pro; Xaa at position 95 is His, Gin, Pro, Arg, Val, Leu, Gly, Thr, Asn, Lys, Ser, Ala, Trp, Phe, lie, or Tyr; Xaa at position 96 is Pro, Lys, Tyr, Gly, lie, or Thr; Xaa at position 97 is lie, Val, Lys, Ala, or Asn; Xaa at position 98 is His, lie, Asn, Leu, Asp, Ala, Thr, Glu, Gin, Ser, Phe, Met, Val, Lys, Arg, Tyr or Pro; Xaa at position 99 is lie, Leu, Arg, Asp, Val, Pro, Gin, Gly, Ser, Phe, or His; Xaa at position 100 is Lys, Tyr, Leu, His, Arg, lie, Ser, Gin, or Pro; Xaa at position 101 is Asp, Pro, Met, Lys, His, Thr, Val, Tyr, Glu, Asn, Ser, Ala, Gly, lie, Leu, or Gin; Xaa at position 102 is Gly, Leu, Glu, Lys, Ser, Tyr, or Pro; Xaa at position 103 is Asp, or Ser; Xaa at position 104 is Trp, Val, Cys, Tyr, Thr, Met, Pro, Leu, Gin, Lys, Ala, Phe, or Gly; Xaa at position 105 is Asn, Pro, Ala, Phe, Ser, Trp, Gin, Tyr, Leu, Lys, lie, Asp, or His; Xaa at position 106 is Glu, Ser, Ala, Lys, Thr, lie, Gly, or Pro; Xaa at position 108 is Arg, Lys, Asp, Leu, Thr, lie, Gin, His, Ser, Ala or Pro; Xaa at position 109 is Arg, Thr, Pro, Glu, Tyr, Leu, Ser, or Gly; Xaa at position 110 is Lys, Ala, Asn, Thr, Leu, Arg, Gin, His, Glu, Ser, Ala, or Trp; Xaa at position 111 is Leu, lie, Arg, Asp, or Met; Xaa at position 112 is Thr, Val, Gin, Tyr, Glu, His, Ser, or Phe; Xaa at position 113 is Phe, Ser, Cys, His, Gly, Trp, Tyr, Asp, Lys, Leu, lie, Val or Asn; Xaa at position 114 is Tyr, Cys, His, Ser, Trp, Arg, or Leu; Xaa at position 115 is Leu, Asn, Val, Pro, Arg, Ala, His, Thr, Trp, or Met; Xaa at position 116 is Lys, Leu, Pro, Thr, Met, Asp, Val, Glu, Arg, Trp, Ser, Asn, His, Ala, Tyr, Phe, Gin, or lie; Xaa at position 117 is Thr, Ser, Asn, lie, Trp, Lys, or Pro; Xaa at position 118 is Leu, Ser, Pro, Ala, Glu, Cys, Asp, or Tyr; Xaa at position 119 is Glu, Ser, Lys, Pro, Leu, Thr, Tyr, or Arg; Xaa at position 120 is Asn, Ala, Pro, Leu, His, Val, or Gin; Xaa at position 121 is Ala, Ser, lie, Asn, Pro, Lys, Asp, or Gly; Xaa at position 122 is Gin, Ser, Met, Trp, Arg, Phe, Pro, His, lie, Tyr, or Cys; Xaa at position 123 is Ala, Met, Glu, His, Ser, Pro, Tyr, or Leu; and which can additionally have Met- preceding the amino acid in position 1; and wherein from 1 to 14 amino acids can be deleted from the N-terminus and/or from 1 to 15 amino acids can be deleted from the C-terminus; and wherein from 1 to 31 of the amino acids designated by Xaa are different from the corresponding amino acids of native (1- 133) human interleukin-3; A colony stimulating factor selected from the group consisting of GM-CSF, CSF-1, G-CSF, Meg-CSF, M-CSF, erythropoietin (EPO), IL-1, IL-4, IL-2, IL- 5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13, LIF, flt3/flk2, human growth hormone, B- cell growth factor, B-cell differentiation factor, eosinophil differentiation factor and stem cell factor (SCF) ; and At least one non-toxic pharmaceutically acceptable carrier. 2. A composition, comprising: A human interleukin-3 mutant polypeptide of the Formula: Ala Pro Met Thr Gin Thr Thr Ser Leu Lys Thr Ser Trp Val Asn 1 5 10 15 Cys Xaa Xaa Xaa lie Xaa Glu Xaa Xaa Xaa Xaa Leu Lys Xaa Xaa 20 25 30 Xaa Xaa Xaa Xaa Xaa Asp Xaa Xaa Asn Leu Asn Xaa Glu Xaa Xaa 35 40 45 Xaa lie Leu Met Xaa Xaa Asn Leu Xaa Xaa Xaa Asn Leu Glu Xaa 50 55 60 Phe Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Asn Xaa Xaa Xaa lie Glu 65 70 75 Xaa Xaa Leu Xaa Xaa Leu Xaa Xaa Cys Xaa Pro Xaa Xaa Thr Ala 80 85 90 Xaa Pro Xaa Arg Xaa Xaa Xaa Xaa Xaa Xaa Xaa Gly Asp Xaa Xaa 95 100 105 Xaa Phe Xaa Xaa Lys Leu Xaa Phe Xaa Xaa Xaa Xaa Leu Glu Xaa 110 115 120 Xaa Xaa Xaa Gin Gin Thr Thr Leu Ser Leu Ala lie Phe 125 130 [SEQ ID Nθ:17] wherein Xaa at position 17 is Ser, Gly, Asp, Met, or Gin; Xaa at position 18 is Asn, His, or lie; Xaa at position 19 is Met or lie; Xaa at position 21 is Asp or Glu; Xaa at position 23 is lie, Ala, Leu, or Gly; Xaa at position 24 is lie, Val, or Leu; Xaa at position 25 is Thr, His, Gin, or Ala; Xaa at position 26 is His or Ala; Xaa at position 29 is Gin, Asn, or Val; Xaa at position 30 is Pro, Gly, or Gin; Xaa at position 31 is Pro, Asp, Gly, or Gin; Xaa at position 32 is Leu, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 33 is Pro or Glu; Xaa at position 34 is Leu, Val, Gly, Ser, Lys, Ala, Arg, Gin, Glu, lie, Phe, Thr or Met; Xaa at position 35 is Leu, Ala, Asn, Pro, Gin, or Val; Xaa at position 37 is Phe, Ser, Pro, or Trp; Xaa at position 38 is Asn or Ala; Xaa at position 42 is Gly, Asp, Ser, Cys, Ala, Asn, lie, Leu, Met, Tyr or Arg; Xaa at position 44 is Asp or Glu; Xaa at position 45 is Gin, Val, Met, Leu, Thr, Ala, Asn, Glu, Ser or Lys; Xaa at position 46 is Asp, Phe, Ser, Thr, Ala, Asn Gin, Glu, His, lie, Lys, Tyr, Val or Cys; Xaa at position 50 is Glu, Ala, Asn, Ser or Asp; Xaa at position 51 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 54 is Arg or Ala; Xaa at position 55 is Arg, Thr, Val, Leu, or Gly; Xaa at position 56 is Pro, Gly, Ser, Gin, Ala, Arg, Asn, Glu, Leu, Thr, Val or Lys; Xaa at position 60 is Ala or Ser; Xaa at position 62 is Asn, Pro, Thr, or lie; Xaa at position 63 is Arg or Lys; Xaa at position 64 is Ala or Asn; Xaa at position 65 is Val or Thr; Xaa at position 66 is Lys or Arg; Xaa at position 67 is Ser, Phe, or His; Xaa at position 68 is Leu, lie, Phe, or His; Xaa at position 69 is Gin, Ala, Pro, Thr, Glu, Arg, or Gly; Xaa at position 71 is Ala, Pro, or Arg; Xaa at position 72 is Ser, Glu, Arg, or Asp; Xaa at position 73 is Ala or Leu; Xaa at position 76 is Ser, Val, Ala, Asn, Glu, Pro, or Gly; Xaa at position 77 is lie or Leu; Xaa at position 79 is Lys, Thr, Gly, Asn, Met, Arg, lie, Gly, or Asp; Xaa at position 80 is Asn, Gly, Glu, or Arg; Xaa at position 82 is Leu, Gin, Trp, Arg, Asp, Ala, Asn, Glu, His, lie, Met, Phe, Ser, Thr, Tyr or Val; Xaa at position 83 is Pro or Thr; Xaa at position 85 is Leu or Val; Xaa at position 87 is Leu or Ser; Xaa at position 88 is Ala or Trp; Xaa at position 91 is Ala or Pro; Xaa at position 93 is Thr, Asp, Ser, Pro, Ala, Leu, or Arg; Xaa at position 95 is His, Pro, Arg, Val, Leu, Gly, Asn, Phe, Ser or Thr; Xaa at position 96 is Pro or Tyr; Xaa at position 97 is lie or Val; Xaa at position 98 is His, lie, Asn, Leu, Ala, Thr, Leu, Arg, Gin, Leu, Lys, Met, Ser, Tyr, Val or Pro; Xaa at position 99 is lie, Leu, or Val; Xaa at position 100 is Lys, Arg, lie, Gin, Pro, or Ser; Xaa at position 101 is Asp, Pro, Met, Lys, His, Thr, Pro, Asn, lie, Leu or Tyr; Xaa at position 104 is Trp or Leu; Xaa at position 105 is Asn, Pro, Ala, Ser, Trp, Gin, Tyr, Leu, Lys, lie. Asp, or His; Xaa at position 106 is Glu or Gly; Xaa at position 108 is Arg, Ala, or Ser; Xaa at position 109 is Arg, Thr, Glu, Leu, or Ser; Xaa at position 112 is Thr, Val, or Gln; Xaa at position 114 is Tyr or Trp; Xaa at position 115 is Leu or Ala; Xaa at position 116 is Lys, Thr, Val, Trp, Ser, Ala, His, Met, Phe, Tyr or lie; Xaa at position 117 is Thr or Ser; Xaa at position 120 is Asn, Pro, Leu, His, Val, or Gin; Xaa at position 121 is Ala, Ser, lie, Asn, Pro, Asp, or Gly; Xaa at position 122 is Gin, Ser, Met, Trp, Arg, Phe, Pro, His, lie, Tyr, or Cys; Xaa at position 123 is Ala, Met, Glu, His, Ser, Pro, Tyr, or Leu; and which can additionally have Met- preceding the amino acid in position 1; and wherein from 1 to 14 amino acids can be deleted from the N-terminus and/or from 1 to 15 amino acids can be deleted from the C-terminus; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native (1- 133)human interleukin-3; A colony stimulating factor ; and At least one non-toxic pharmaceutically acceptable carrier. 3. A composition of claim 2, wherein said human interleukin-3 mutant polypeptide is of the Formula: Ala Pro Met Thr Gin Thr Thr Ser Leu Lys Thr Ser Trp Val Asn 1 5 10 15 Cys Xaa Xaa Met lie Asp Glu Xaa lie Xaa Xaa Leu Lys Xaa Xaa 20 25 30 Pro Xaa Pro Xaa Xaa Asp Phe Xaa Asn Leu Asn Xaa Glu Asp Xaa 35 40 45 Xaa lie Leu Met Xaa Xaa Asn Leu Arg Xaa Xaa Asn Leu Glu Ala 50 55 60 Phe Xaa Arg Xaa Xaa Lys Xaa Xaa Xaa Asn Ala Ser Ala lie Glu 65 70 75 Xaa Xaa Leu Xaa Xaa Leu Xaa Pro Cys Leu Pro Xaa Xaa Thr Ala 80 85 90 Xaa Pro Xaa Arg Xaa Pro lie Xaa Xaa Xaa Xaa Gly Asp Trp Xaa 95 100 105 Glu Phe Xaa Xaa Lys Leu Xaa Phe Tyr Leu Xaa Xaa Leu Glu Xaa 110 115 120 Xaa Xaa Xaa Gin Gin Thr Thr Leu Ser Leu Ala lie Phe 125 130 [SEQ ID NO:18] wherein Xaa at position 17 is Ser, Gly, Asp, or Gin; Xaa at position 18 is Asn, His, or lie; Xaa at position 23 is lie, Ala, Leu, or Gly; Xaa at position 25 is Thr, His, or Gin; Xaa at position 26 is His or Ala; Xaa at position 29 is Gin or Asn; Xaa at position 30 is Pro or Gly; Xaa at position 32 is Leu, Arg, Asn, or Ala; Xaa at position 34 is Leu, Val, Ser, Ala, Arg, Gin, Glu, lie, Phe, Thr, or Met; Xaa at position 35 is Leu, Ala, Asn, or Pro; Xaa at position 38 is Asn or Ala; Xaa at position 42 is Gly, Asp, Ser, Ala, Asn, lie, Leu, Met, Tyr or Arg; Xaa at position 45 is Gin, Val, Met, Leu, Ala, Asn, Glu, or Lys; Xaa at position 46 is Asp, Phe, Ser, Gin, Glu, His, Val or Thr; Xaa at position 50 is Glu Asn, Ser or Asp; Xaa at position 51 is Asn, Arg, Pro, Thr, or His; Xaa at position 55 is Arg, Leu, or Gly; Xaa at position 56 is Pro, Gly, Ser, Ala, Asn, Val, Leu or Gin; Xaa at position 62 is Asn, Pro, or Thr; Xaa at position 64 is Ala or Asn; Xaa at position 65 is Val or Thr; Xaa at position 67 is Ser or Phe; Xaa at position 68 is Leu or Phe; Xaa at position 69 is Gin, Ala, Glu, or Arg; Xaa at position 76 is Ser, Val, Asn, Pro, or Gly; Xaa at position 77 is lie or Leu; Xaa at position 79 is Lys, Gly, Asn, Met, Arg, lie, or Gly; Xaa at position 80 is Asn, Gly, Glu, or Arg; Xaa at position 82 is Leu, Gin, Trp, Arg, Asp, Asn, Glu, His, Met, Phe, Ser, Thr, Tyr or Val; Xaa at position 87 is Leu or Ser; Xaa at position 88 is Ala or Trp; Xaa at position 91 is Ala or Pro; Xaa at position 93 is Thr, Asp, or Ala; Xaa at position 95 is His, Pro, Arg, Val, Gly, Asn, Ser or Thr; Xaa at position 98 is His, lie, Asn, Ala, Thr, Gin, Glu, Lys, Met, Ser, Tyr, Val or Leu; Xaa at position 99 is lie or Leu; Xaa at position 100 is Lys or Arg; Xaa at position 101 is Asp, Pro, Met, Lys, Thr, His, Pro, Asn, lie, Leu or Tyr; Xaa at position 105 is Asn, Pro, Ser, lie or Asp; Xaa at position 108 is Arg, Ala, or Ser; Xaa at position 109 is Arg, Thr, Glu, Leu, or Ser; Xaa at position 112 is Thr or Gin; Xaa at position 116 is Lys, Val, Trp, Ala, His, Phe, Tyr or lie; Xaa at position 117 is Thr or Ser; Xaa at position 120 is Asn, Pro, Leu, His, Val, or Gin; Xaa at position 121 is Ala, Ser, lie, Pro, or Asp; Xaa at position 122 is Gin, Met, Trp, Phe, Pro, His, lie, or Tyr; Xaa at position 123 is Ala, Met, Glu, Ser, or Leu; and which can additionally have Met- preceding the amino acid in position 1; and wherein from 1 to 14 amino acids can be deleted from the N-terminus and/or from 1 to 15 amino acids can be deleted from the C-terminus; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native (1- 133)human interleukin-3. 4. A composition of claim 3, wherein said human interleukin-3 mutant polypeptide is of the Formula : Xaa at position 42 is Gly, Asp, Ser, lie, Leu, Met, Tyr, or Ala; Xaa at position 45 is Gin, Val, Met or Asn; Xaa at position 46 is Asp, Ser, Gin, His or Val; Xaa at position 50 is Glu or Asp; Xaa at position 51 is Asn, Pro or Thr; Xaa at position 62 is Asn or Pro; Xaa at position 76 is Ser, or Pro; Xaa at position 82 is Leu, Trp, Asp, Asn Glu, His, Phe, Ser or Tyr; Xaa at position 95 is His, Arg, Thr, Asn or Ser; Xaa at position 98 is His, lie, Leu, Ala, Gin, Lys, Met, Ser, Tyr or Val; Xaa at position 100 is Lys or Arg; Xaa at position 101 is Asp, Pro, His, Asn, lie or Leu; Xaa at position 105 is Asn, or Pro; Xaa at position 108 is Arg, Ala, or Ser; Xaa at position 116 is Lys, Val, Trp, Ala, His, Phe, or Tyr; Xaa at position 121 is Ala, or lie; Xaa at position 122 is Gin, or lie; and Xaa at position 123 is Ala, Met or Glu. 5. A composition, comprising: A human interleukin-3 mutant polypeptide of the Formula: Asn Cys Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 1 5 10 15 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Asn Xaa Xaa Xaa Xaa Xaa 20 25 30 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 35 40 45 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 50 55 60 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 65 70 75 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 80 85 90 Xaa Xaa Phe Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 95 100 105 Xaa Xaa Xaa Xaa Gin Gin [SEQ ID NO:19] 110 wherein Xaa at position 3 is Ser, Lys, Gly, Asp, Met, Gin, or Arg Xaa at position 4 is Asn, His, Leu, lie, Phe, Arg, or Gin Xaa at position 5 is Met, Phe, lie, Arg, Gly, Ala, or Cys Xaa at position 6 is lie, Cys, Gin, Glu, Arg, Pro, or Ala Xaa at position 7 is Asp, Phe, Lys, Arg, Ala, Gly, Glu, Gin, Asn, Thr, Ser or Val; Xaa at position 8 is Glu, Trp, Pro, Ser, Ala, His, Asp, Asn, Gin, Leu, Val, or Gly; Xaa at position 9 is lie, Val, Ala, Leu, Gly, Trp, Lys, Phe, Leu, Ser, or Arg; Xaa at position 10 is lie, Gly, Val, Arg, Ser, Phe, or Leu; Xaa at position 11 is Thr, His, Gly, Gin, Arg, Pro, or Ala; Xaa at position 12 is His, Thr, Phe, Gly, Arg, Ala, or Trp; Xaa at position 13 is Leu, Gly, Arg, Thr, Ser, or Ala; Xaa at position 14 is Lys, Arg, Leu, Gin, Gly, Pro, Val or Trp; Xaa at position 15 is Gin, Asn, Leu, Pro, Arg, or Val; Xaa at position 16 is Pro, His, Thr, Gly, Asp, Gin, Ser, Leu, or Lys; Xaa at position 17 is Pro, Asp, Gly, Ala, Arg, Leu, or Gin; Xaa at position 18 is Leu, Val, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 19 is Pro, Leu, Gin, Ala, Thr, or Glu; Xaa at position 20 is Leu, Val, Gly, Ser, Lys, Glu, Gin, Thr, Arg, Ala, Phe, lie or Met; Xaa at position 21 is Leu, Ala, Gly, Asn, Pro, Gin, or Val; Xaa at position 22 is Asp, Leu, or Val; Xaa at position 23 is Phe, Ser, Pro, Trp, or lie; Xaa at position 24 is Asn, or Ala; Xaa at position 26 is Leu, Trp, or Arg; Xaa at position 27 is Asn, Cys, Arg, Leu, His, Met, Pro; Xaa at position 28 is Gly, Asp, Ser, Cys, Ala, Lys, Asn, Thr, Leu, Val, Glu, Phe, Tyr, lie or Met; Xaa at position 29 is Glu, Asn, Tyr, Leu, Phe, Asp, Ala, Cys, Gin, Arg, Thr, Gly or Ser; Xaa at position 30 is Asp, Ser, Leu, Arg, Lys, Thr, et, Trp, Glu, Asn, Gin, Ala or Pro; Xaa at position 31 is Gin, Pro, Phe, Val, Met, Leu, Thr, Lys, Asp, Asn, Arg, Ser, Ala, lie, Glu, His or Trp; Xaa at position 32 is Asp, Phe, Ser, Thr, Cys, Glu, Asn, Gin, Lys, His, Ala, Tyr, lie, Val or Gly; Xaa at position 33 is lie, Gly, Val, Ser, Arg, Pro, or His; Xaa at position 34 is Leu, Ser, Cys, Arg, lie, His, Phe, Glu, Lys, Thr, Ala, Met, Val or Asn; Xaa at position 35 is Met, Arg, Ala, Gly, Pro, Asn, His, or Asp; Xaa at position 36 is Glu, Leu, Thr, Asp, Tyr, Lys, Asn, Ser, Ala, lie, Val, His, Phe, Met or Gin; Xaa at position 37 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 38 is Asn, His, Arg, Leu, Gly, Ser, or Thr; Xaa at position 39 is Leu, Thr, Ala, Gly, Glu, Pro, Lys, Ser, Met, or; Xaa at position 40 is Arg, Asp, lie, Ser, Val, Thr, Gin, Asn, Lys, His, Ala or Leu; Xaa at position 41 is Arg, Thr, Val, Ser, Leu, or Gly; Xaa at position 42 is Pro, Gly, Cys, Ser, Gin, Glu, Arg, His, Thr, Ala, Tyr, Phe, Leu, Val or Lys; Xaa at position 43 is Asn or Gly; Xaa at position 44 is Leu, Ser, Asp, Arg, Gin, Val, or Cys; Xaa at position 45 is Glu Tyr, His, Leu, Pro, or Arg; Xaa at position 46 is Ala, Ser, Pro, Tyr, Asn, or Thr; Xaa at position 47 is Phe, Asn, Glu, Pro, Lys, Arg, or Ser; Xaa at position 48 is Asn, His, Val, Arg, Pro, Thr, Asp, or lie; Xaa at position 49 is Arg, Tyr, Trp, Lys, Ser, His, Pro, or Val; Xaa at position 50 is Ala, Asn, Pro, Ser, or Lys; Xaa at position 51 is Val, Thr, Pro, His, Leu, Phe, or Ser; Xaa at position 52 is Lys, lie, Arg, Val, Asn, Glu, or Ser; Xaa at position 53 is Ser, Ala, Phe, Val, Gly, Asn, lie, Pro, or His; Xaa at position 54 is Leu, Val, Trp, Ser, lie, Phe, Thr, or His; Xaa at position 55 is Gin, Ala, Pro, Thr, Glu, Arg, Trp, Gly, or Leu; Xaa at position 56 is Asn, Leu, Val, Trp, Pro, or Ala; Xaa at position 57 is Ala, Met, Leu, Pro, Arg, Glu, Thr, Gin, Trp, or Asn; Xaa at position 58 is Ser, Glu, Met, Ala, His, Asn, Arg, or Asp; Xaa at position 59 is Ala, Glu, Asp, Leu, Ser, Gly, Thr, or Arg; Xaa at position 60 is lie, Met, Thr, Pro, Arg, Gly, Ala; Xaa at position 61 is Glu, Lys, Gly, Asp, Pro, Trp, Arg, Ser, Gin, or Leu; Xaa at position 62 is Ser, Val, Ala, Asn, Trp, Glu, Pro, Gly, or Asp; Xaa at position 63 is lie, Ser, Arg, Thr, or Leu; Xaa at position 64 is Leu, Ala, Ser, Glu, Phe, Gly, or Arg; Xaa at position 65 is Lys, Thr, Gly, Asn, Met, Arg, lie, or Asp; Xaa at position 66 is Asn, Trp, Val, Gly, Thr, Leu, Glu, or Arg; Xaa at position 67 is Leu, Gin, Gly, Ala, Trp, Arg, Val, or Lys; Xaa at position 68 is Leu, Gin, Lys, Trp, Arg, Asp, Glu, Asn, His, Thr, Ser, Ala, Tyr, Phe, lie, Met or Val; Xaa at position 69 is Pro, Ala, Thr, Trp, Arg, or Met; Xaa at position 70 is Cys, Glu, Gly, Arg, Met, or Val; Xaa at position 71 is Leu, Asn, Val, or Gin; Xaa at position 72 is Pro, Cys, Arg, Ala, or Lys; Xaa at position 73 is Leu, Ser, Trp, or Gly; Xaa at position 74 is Ala, Lys, Arg, Val, or Trp; Xaa at position 75 is Thr, Asp, Cys, Leu, Val, Glu, His, Asn, or Ser; Xaa at position 76 is Ala, Pro, Ser, Thr, Gly, Asp, lie, or Met; Xaa at position 77 is Ala, Pro, Ser, Thr, Phe, Leu, Asp, or His; Xaa at position 78 is Pro, Phe, Arg, Ser, Lys, His, Ala, Gly, lie or Leu; Xaa at position 79 is Thr, Asp, Ser, Asn, Pro, Ala, Leu, or Arg; Xaa at position 80 is Arg, lie, Ser, Glu, Leu, Val, Gin, Lys, His, Ala or Pro; Xaa at position 81 is His, Gin, Pro, Arg, Val, Leu, Gly, Thr, Asn, Lys, Ser, Ala, Trp, Phe, lie or Tyr; Xaa at position 82 is Pro, Lys, Tyr, Gly, lie, or Thr; Xaa at position 83 is lie, Val, Lys, Ala, or Asn; Xaa at position 84 is His, lie, Asn, Leu, Asp, Ala, Thr, Glu, Gin, Ser, Phe, Met, Val, Lys, Arg, Tyr or Pro; Xaa at position 85 is lie, Leu, Arg, Asp, Val, Pro, Gin, Gly, Ser, Phe, or His; Xaa at position 86 is Lys, Tyr, Leu, His, Arg, lie, Ser, Gin, Pro; Xaa at position 87 is Asp, Pro, Met, Lys, His, Thr, Val, Tyr, Glu, Asn, Ser, Ala, Gly, lie, Leu or Gin; Xaa at position 88 is Gly, Leu, Glu, Lys, Ser, Tyr, or Pro; Xaa at position 89 is Asp, or Ser; Xaa at position 90 is Trp, Val, Cys, Tyr, Thr, Met, Pro, Leu, Gin, Lys, Ala, Phe, or Gly; Xaa at position 91 is Asn, Pro, Ala, Phe, Ser, Trp, Gin, Tyr, Leu, Lys, lie, Asp, or His; Xaa at position 92 is Glu, Ser, Ala, Lys, Thr, lie, Gly, or Pro; Xaa at position 94 is Arg, Lys, Asp, Leu, Thr, lie. Gin, His, Ser, Ala, or Pro; Xaa at position 95 is Arg, Thr, Pro, Glu, Tyr, Leu, Ser, or Gly; Xaa at position 96 is Lys, Asn, Thr, Leu, Gin, Arg, His, Glu, Ser, Ala or Trp; Xaa at position 97 is Leu, lie, Arg, Asp, or Met; Xaa at position 98 is Thr, Val, Gin, Tyr, Glu, His, Ser, or Phe; Xaa at position 99 is Phe, Ser, Cys, His, Gly, Trp, Tyr, Asp, Lys, Leu, lie, Val or Asn; Xaa at position 100 is Tyr, Cys, His, Ser, Trp, Arg, or Leu; Xaa at position 101 is Leu, Asn, Val, Pro, Arg, Ala, His, Thr, Trp, or Met; Xaa at position 102 is Lys, Leu, Pro, Thr, Met, Asp, Val, Glu , Arg, Trp, Ser, Asn , His , Ala , Tyr , Phe , Gin , or lie; Xaa at position 103 is Thr, Ser, Asn, lie, Trp, Lys, or Pro; Xaa at position 104 is Leu, Ser, Pro, Ala, Glu, Cys, Asp, or Tyr; Xaa at position 105 is Glu, Ser, Lys, Pro, Leu, Thr, Tyr, or Arg; Xaa at position 106 is Asn, Ala, Pro, Leu, His, Val, or Gin; Xaa at position 107 is Ala, Ser, lie, Asn, Pro, Lys, Asp, or Gly; Xaa at position 108 is Gin, Ser, Met, Trp, Arg, Phe, Pro, His, lie, Tyr, or Cys; Xaa at position 109 is Ala, Met, Glu, His, Ser, Pro, Tyr, or Leu; and which can additionally have Met- or Met-Ala- preceding the amino acid in position 1 ; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding native amino acids of ( 1-133 ) human interleukin-3 ; A colony stimulating factor ; and At least one non-toxic pharmaceutically acceptable carrier . 6. A composition of claim 5 , wherein said human interleukin-3 mutant polypeptide is of the Formula : Asn Cys Xaa Xaa Xaa lie Xaa Glu Xaa Xaa Xaa Xaa Leu Lys Xaa 1 5 10 15 Xaa Xaa Xaa Xaa Xaa Xaa Asp Xaa Xaa Asn Leu Asn Xaa Glu Xaa 20 25 30 Xaa Xaa lie Leu Met Xaa Xaa Asn Leu Xaa Xaa Xaa Asn Leu Glu 35 40 45 Xaa Phe Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Asn Xaa Xaa Xaa lie 50 55 60 Glu Xaa Xaa Leu Xaa Xaa Leu Xaa Xaa Cys Xaa Pro Xaa Xaa Thr 65 70 75 Ala Xaa Pro Xaa Arg Xaa Xaa Xaa Xaa Xaa Xaa Xaa Gly Asp Xaa 80 85 90 Xaa Xaa Phe Xaa Xaa Lys Leu Xaa Phe Xaa Xaa Xaa Xaa Leu Glu 95 100 105 Xaa Xaa Xaa Xaa Gin Gin [SEQ ID NO:21] 110 wherein Xaa at position 3 is Ser, Gly, Asp, Met, or Gin; Xaa at position 4 is Asn, His, or lie; Xaa at position 5 is Met or lie; Xaa at position 7 is Asp or Glu; Xaa at position 9 is lie, Ala, Leu, or Gly; Xaa at position 10 is lie, Val, or Leu; Xaa at position 11 is Thr, His, Gin, or Ala; Xaa at position 12 is His or Ala; Xaa at position 15 is Gin, Asn, or Val; Xaa at position 16 is Pro, Gly, or Gin; Xaa at position 17 is Pro, Asp, Gly, or Gin; Xaa at position 18 is Leu, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 19 is Pro or Glu; Xaa at position 20 is Leu, Val, Gly, Ser, Lys, Ala, Arg, Gin, Glu, lie, Phe, Thr or Met; Xaa at position 21 is Leu, Ala, Asn, Pro, Gin, or Val; Xaa at position 23 is Phe, Ser, Pro, or Trp; Xaa at position 24 is Asn or Ala; Xaa at position 28 is Gly, Asp, Ser, Cys, Ala, Asn, lie, Leu, Met Tyr or Arg; Xaa at position 30 is Asp or Glu; Xaa at position 31 is Gin, Val, Met, Leu, Thr, Ala, Asn, Glu, Ser or Lys; Xaa at position 32 is Asp, Phe, Ser, Thr, Ala, Asn, Gin, Glu, His, lie, Lys, Tyr, Val or Cys; Xaa at position 36 is Glu, Ala, Asn, Ser or Asp; Xaa at position 37 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 40 is Arg or Ala; Xaa at position 41 is Arg, Thr, Val, Leu, or Gly; Xaa at position 42 is Pro, Gly, Ser, Gin, Ala, Arg, Asn, Glu, Leu, Thr, Val or Lys; Xaa at position 46 is Ala or Ser; Xaa at position 48 is Asn, Pro, Thr, or lie; Xaa at position 49 is Arg or Lys; Xaa at position 50 is Ala or Asn; Xaa at position 51 is Val or Thr; Xaa at position 52 is Lys or Arg; Xaa at position 53 is Ser, Phe, or His; Xaa at position 54 is Leu, lie, Phe, or His; Xaa at position 55 is Gin, Ala, Pro, Thr, Glu, Arg, or Gly; Xaa at position 57 is Ala, Pro, or Arg; Xaa at position 58 is Ser, Glu, Arg, or Asp; Xaa at position 59 is Ala or Leu; Xaa at position 62 is Ser, Val, Ala, Asn, Glu, Pro, or Gly; Xaa at position 63 is lie or Leu; Xaa at position 65 is Lys, Thr, Gly, Asn, Met, Arg, lie, Gly, or Asp; Xaa at position 66 is Asn, Gly, Glu, or Arg; Xaa at position 68 is Leu, Gin, Trp, Arg, Asp, Ala, Asn, Glu, His, lie, Met, Phe, Ser, Thr, Tyr or Val; Xaa at position 69 is Pro or Thr; Xaa at position 71 is Leu or Val; Xaa at position 73 is Leu or Ser; Xaa at position 74 is Ala or Trp; Xaa at position 77 is Ala or Pro; Xaa at position 79 is Thr, Asp, Ser, Pro, Ala, Leu, or Arg; Xaa at position 81 is His, Pro, Arg, Val, Leu, Gly, Asn, Phe, Ser or Thr; Xaa at position 82 is Pro or Tyr; Xaa at position 83 is lie or Val; Xaa at position 84 is His, lie, Asn, Leu, Ala, Thr, Leu, Arg, Gin, Leu, Lys, Met, Ser, Tyr, Val or Pro; Xaa at position 85 is lie, Leu, or Val; Xaa at position 86 is Lys, Arg, lie, Gin, Pro, or Ser; Xaa at position 87 is Asp, Pro, Met, Lys, His, Thr, Asn, lie, Leu or Tyr; Xaa at position 90 is Trp or Leu; Xaa at position 91 is Asn, Pro, Ala, Ser, Trp, Gin, Tyr, Leu, Lys, lie, Asp, or His; Xaa at position 92 is Glu, or Gly; Xaa at position 94 is Arg, Ala, or Ser; Xaa at position 95 is Arg, Thr, Glu, Leu, or Ser; Xaa at position 98 is Thr, Val, or Gin; Xaa at position 100 is Tyr or Trp; Xaa at position 101 is Leu or Ala; Xaa at position 102 is Lys, Thr, Val, Trp, Ser, Ala, His, Met, Phe, Tyr or lie; Xaa at position 103 is Thr or Ser; Xaa at position 106 is Asn, Pro, Leu, His, Val, or Gin; Xaa at position 107 is Ala, Ser, lie, Asn, Pro, Asp, or Gly; Xaa at position 108 is Gin, Ser, Met, Trp, Arg, Phe, Pro, His, lie, Tyr, or Cys; Xaa at position 109 is Ala, Met, Glu, His, Ser, Pro, Tyr, or Leu; which can additionally have Met- or Met-Ala- preceding the amino acid in position 1; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native human interleukin-3. 7. A composition of claim 6, wherein said human interleukin-3 mutant polypeptide is of the Formula: Asn Cys Xaa Xaa Met lie Asp Glu Xaa lie Xaa Xaa Leu Lys Xaa 1 5 10 15 Xaa Pro Xaa Pro Xaa Xaa Asp Phe Xaa Asn Leu Asn Xaa Glu Asp 20 25 30 Xaa Xaa lie Leu Met Xaa Xaa Asn Leu Arg Xaa Xaa Asn Leu Glu 35 40 45 Ala Phe Xaa Arg Xaa Xaa Lys Xaa Xaa Xaa Asn Ala Ser Ala lie 50 55 60 Glu Xaa Xaa Leu Xaa Xaa Leu Xaa Pro Cys Leu Pro Xaa Xaa Thr 65 70 75 Ala Xaa Pro Xaa Arg Xaa Pro lie Xaa Xaa Xaa Xaa Gly Asp Trp 80 85 90 Xaa Glu Phe Xaa Xaa Lys Leu Xaa Phe Tyr Leu Xaa Xaa Leu Glu 95 100 105 Xaa Xaa Xaa Xaa Gin Gin [SEQ ID NO:22] 110 wherein Xaa at position 3 is Ser, Gly, Asp, or Gin; Xaa at position 4 is Asn, His, or lie; Xaa at position 9 is lie, Ala, Leu, or Gly; Xaa at position 11 is Thr, His, or Gin; Xaa at position 12 is His or Ala; Xaa at position 15 is Gin or Asn; Xaa at position 16 is Pro or Gly; Xaa at position 18 is Leu, Arg, Asn, or Ala; Xaa at position 20 is Leu, Val, Ser, Ala, Arg, Gin, Glu, lie, Phe, Thr or Met; Xaa at position 21 is Leu, Ala, Asn, or Pro; Xaa at position 24 is Asn or Ala; Xaa at position 28 is Gly, Asp, Ser, Ala, Asn, lie, Leu, Met, Tyr or Arg; Xaa at position 31 is Gin, Val, Met, Leu, Ala, Asn, Glu or Lys; Xaa at position 32 is Asp, Phe, Ser, Ala, Gin, Glu, His, Val or Thr; Xaa at position 36 is Glu, Asn, Ser or Asp; Xaa at position 37 is Asn, Arg, Pro, Thr, or His; Xaa at position 41 is Arg, Leu, or Gly; Xaa at position 42 is Pro, Gly, Ser, Ala, Asn, Val, Leu or Gin; Xaa at position 48 is Asn, Pro, or Thr; Xaa at position 50 is Ala or Asn; Xaa at position 51 is Val or Thr; Xaa at position 53 is Ser or Phe; Xaa at position 54 is Leu or Phe; Xaa at position 55 is Gin, Ala, Glu, or Arg; Xaa at position 62 is Ser, Val, Asn, Pro, or Gly; Xaa at position 63 is lie or Leu; Xaa at position 65 is Lys, Asn, Met, Arg, lie, or Gly; Xaa at position 66 is Asn, Gly, Glu, or Arg; Xaa at position 68 is Leu, Gin, Trp, Arg, Asp, Asn, Glu, His, Met, Phe, Ser, Thr, Tyr or Val; Xaa at position 73 is Leu or Ser; Xaa at position 74 is Ala or Trp; Xaa at position 77 is Ala or Pro; Xaa at position 79 is Thr, Asp, or Ala; Xaa at position 81 is His, Pro, Arg, Val, Gly, Asn, Ser or Thr; Xaa at position 84 is His, lie, Asn, Ala, Thr, Arg, Gin, Glu, Lys, Met, Ser, Tyr, Val or Leu; Xaa at position 85 is lie or Leu; Xaa at position 86 is Lys or Arg; Xaa at position 87 is Asp, Pro, Met, Lys, His, Pro, Asn, lie, Leu or Tyr; Xaa at position 91 is Asn, Pro, Ser, lie or Asp; Xaa at position 94 is Arg, Ala, or Ser; Xaa at position 95 is Arg, Thr, Glu, Leu, or Ser; Xaa at position 98 is Thr or Gin; Xaa at position 102 is Lys, Val, Trp, or lie; Xaa at position 103 is Thr, Ala, His, Phe, Tyr or Ser; Xaa at position 106 is Asn, Pro, Leu, His, Val, or Gin; Xaa at position 107 is Ala, Ser, lie, Pro, or Asp; Xaa at position 108 is Gin, Met, Trp, Phe, Pro, His, lie, or Tyr; Xaa at position 109 is Ala, Met, Glu, Ser, or Leu; and which can additionally have Met- or Met-Ala- preceding the amino acid in position 1; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native (1-133)human interleukin-3. 8. The composition of claim 7, wherein said human interleukin-3 mutant polypeptide is of the Formula: Xaa at position 17 is Ser, Lys, Asp, Met, Gin, or Arg; Xaa at position 18 is Asn, His, Leu, lie, Phe, Arg, or Gin; Xaa at position 19 is Met, Arg, Gly, Ala, or Cys; Xaa at position 20 is lie, Cys, Gin, Glu, Arg, Pro, or Ala; Xaa at position 21 is Asp, Phe, Lys, Arg, Ala, Gly, or Val; Xaa at position 22 is Glu, Trp, Pro, Ser, Ala, His, or Gly; Xaa at position 23 is lie, Ala, Gly, Trp, Lys, Leu, Ser, or Arg; Xaa at position 24 is lie, Gly, Arg, or Ser; Xaa at position 25 is Thr, His, Gly, Gin, Arg, Pro, or Ala; Xaa at position 26 is His, Thr, Phe, Gly, Ala, or Trp; Xaa at position 27 is Leu, Gly, Arg, Thr, Ser, or Ala; Xaa at position 28 is Lys, Leu, Gin, Gly, Pro, Val or Trp; Xaa at position 29 is Gin, Asn, Pro, Arg, or Val; Xaa at position 30 is Pro, His, Thr, Gly, Asp, Gin, Ser, Leu, or Lys; Xaa at position 31 is Pro, Asp, Gly, Arg, Leu, or Gin; Xaa at position 32 is Leu, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 33 is Pro, Leu, Gin, Thr, or Glu; Xaa at position 34 is Leu, Gly, Ser, or Lys; Xaa at position 35 is Leu, Ala, Gly, Asn, Pro, or Gin; Xaa at position 36 is Asp, Leu, or Val; Xaa at position 37 is Phe, Ser, or Pro; Xaa at position 38 is Asn, or Ala; Xaa at position 40 is Leu, Trp, or Arg; Xaa at position 41 is Asn, Cys, Arg, Leu, His, Met, Pro; Xaa at position 42 is Gly, Asp, Ser, Cys, or Ala; Xaa at position 42 is Glu, Asn, Tyr, Leu, Phe, Asp, Ala, Cys, or Ser; Xaa at position 44 is Asp, Ser, Leu, Arg, Lys, Thr, Met, Trp, or Pro; Xaa at position 45 is Gin, Pro, Phe, Val, Met, Leu, Thr, Lys, or Trp; Xaa at position 46 is Asp, Phe, Ser, Thr, Cys, or Gly; Xaa at position 47 is lie, Gly, Ser, Arg, Pro, or His; Xaa at position 48 is Leu, Ser, Cys, Arg, His, Phe, or Asn; Xaa at position 49 is Met, Arg, Ala, Gly, Pro, Asn, His, or Asp; Xaa at position 50 is Glu, Leu, Thr, Asp, or Tyr; Xaa at position 51 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 52 is Asn, His, Arg, Leu, Gly, Ser, or Thr; Xaa at position 53 is Leu, Thr, Ala, Gly, Glu, Pro, Lys, Ser, or; Xaa at position 54 is Arg, Asp, lie, Ser, Val, Thr, Gin, or Leu; Xaa at position 55 is Arg, Thr, Val, Ser, Leu, or Gly; Xaa at position 56 is Pro, Gly, Cys, Ser, Gin, or Lys; Xaa at position 57 is Asn or Gly; Xaa at position 58 is Leu, Ser, Asp, Arg, Gin, Val, or Cys; Xaa at position 59 is Glu Tyr, His, Leu, Pro, or Arg; Xaa at position 60 is Ala, Ser, Tyr, Asn, or Thr; Xaa at position 61 is Phe, Asn, Glu, Pro, Lys, Arg, or Ser; Xaa at position 62 is Asn His, Val, Arg, Pro, Thr, or lie; Xaa at position 63 is Arg, Tyr, Trp, Ser, Pro, or Val; Xaa at position 64 is Ala, Asn, Ser, or Lys; Xaa at position 65 is Val, Thr, Pro, His, Leu, Phe, or Ser; Xaa at position 66 is Lys, lie, Val, Asn, Glu, or Ser; Xaa at position 67 is Ser, Ala, Phe, Val, Gly, Asn, lie. Pro, or His; Xaa at position 68 is Leu, Val, Trp, Ser, Thr, or His; Xaa at position 69 is Gin, Ala, Pro, Thr, Arg, Trp, Gly, or Leu; Xaa at position 70 is Asn, Leu, Val, Trp, Pro, or Ala; Xaa at position 71 is Ala, Met, Leu, Arg, Glu, Thr, Gin, Trp, or Asn; Xaa at position 72 is Ser, Glu, Met, Ala, His, Asn, Arg, or Asp; Xaa at position 73 is Ala, Glu, Asp, Leu, Ser, Gly, Thr, or Arg; Xaa at position 74 is lie, Thr, Pro, Arg, Gly, Ala; Xaa at position 75 is Glu, Lys, Gly, Asp, Pro, Trp, Arg, Ser, or Leu; Xaa at position 76 is Ser, Val, Ala, Asn, Trp, Glu, Pro, Gly, or Asp; Xaa at position 77 is lie, Ser, Arg, or Thr; Xaa at position 78 is Leu, Ala, Ser, Glu, Gly, or Arg; Xaa at position 79 is Lys, Thr, Gly, Asn, Met, lie, or Asp; Xaa at position 80 is Asn, Trp, Val, Gly, Thr, Leu, or Arg; Xaa at position 81 is Leu, Gin, Gly, Ala, Trp, Arg, or Lys,- Xaa at position 82 is Leu, Gin, Lys, Trp, Arg, or Asp; Xaa at position 83 is Pro, Thr, Trp, Arg, or Met; Xaa at position 84 is Cys, Glu, Gly, Arg, Met, or Val; Xaa at position 85 is Leu, Asn, or Gin; Xaa at position 86 is Pro, Cys, Arg, Ala, or Lys; Xaa at position 87 is Leu, Ser, Trp, or Gly; Xaa at position 88 is Ala, Lys, Arg, Val, or Trp; Xaa at position 89 is Thr, Asp, Cys, Leu, Val, Glu, His, or Asn; Xaa at position 90 is Ala, Ser, Asp, lie, or Met; Xaa at position 91 is Ala, Ser, Thr, Phe, Leu, Asp, or His; Xaa at position 92 is Pro, Phe, Arg, Ser, Lys, His, or Leu; Xaa at position 93 is Thr, Asp, Ser, Asn, Pro, Ala, Leu, or Arg; Xaa at position 94 is Arg, lie, Ser, Glu, Leu, Val, or Pro; Xaa at position 95 is His, Gin, Pro, Val, Leu, Thr or Tyr; Xaa at position 96 is Pro, Lys, Tyr, Gly, lie, or Thr; Xaa at position 97 is lie, Lys, Ala, or Asn; Xaa at position 98 is His, lie, Asn, Leu, Asp, Ala, Thr, or Pro; Xaa at position 99 is lie, Arg, Asp, Pro, Gin, Gly, Phe, or His; Xaa at position 100 is Lys, Tyr, Leu, His, lie, Ser, Gin, or Pro; Xaa at position 101 is Asp, Pro, Met, Lys, His, Thr, Val, Tyr, or Gin; Xaa at position 102 is Gly, Leu, Glu, Lys, Ser, Tyr, or Pro; Xaa at position 103 is Asp, or Ser; Xaa at position 104 is Trp, Val, Cys, Tyr, Thr, Met, Pro, Leu, Gin, Lys, Ala, Phe, or Gly; Xaa at position 105 is Asn, Pro, Ala, Phe, Ser, Trp, Gin, Tyr, Leu, Lys, lie, or His; Xaa at position 106 is Glu, Ser, Ala, Lys, Thr, lie, Gly, or Pro; Xaa at position 108 is Arg, Asp, Leu, Thr, lie, or Pro; Xaa at position 109 is Arg, Thr, Pro, Glu, Tyr, Leu, Ser, or Gly. 9. A composition of claim 8, wherein said human interleukin-3 mutant polypeptide is of the Formula: 1 5 10 (Met)m-Ala Pro Met Thr Gin Thr Thr Ser Leu Lys Thr 15 20 Ser Trp Val Asn Cys Ser Xaa Xaa Xaa Asp Glu He He 25 30 35 Xaa His Leu Lys Xaa Pro Pro Xaa Pro Xaa Leu Asp Xaa 40 45 50 Xaa Asn Leu Asn Xaa Glu Asp Xaa Asp He Leu Xaa Glu 55 60 Xaa Asn Leu Arg Xaa Xaa Asn Leu Xaa Xaa Phe Xaa Xaa 65 70 75 Ala Xaa Lys Xaa Leu Xaa Asn Ala Ser Xaa He Glu Xaa 80 85 He Leu Xaa Asn Leu Xaa Pro Cys Xaa Pro Xaa Xaa Thr 90 95 100 Ala Xaa Pro Xaa Arg Xaa Pro He Xaa He Xaa Xaa Gly 105 110 115 Asp Trp Xaa Glu Phe Arg Xaa Lys Leu Xaa Phe Tyr Leu 120 125 Xaa Xaa Leu Glu Xaa Ala Gin Xaa Gin Gin Thr Thr Leu 130 Ser Leu Ala He Phe [SEQ ID NO:129] wherein m is 0 or 1; Xaa at position 18 is Asn or He; Xaa at position 19 is Met, Ala or He; Xaa at position 20 is He, Pro or He; Xaa at position 23 is He, Ala or Leu; Xaa at position 25 is Thr or His; Xaa at position 29 is Gin, Arg, Val or lie; Xaa at position 32 is Leu, Ala, Asn or Arg; Xaa at position 34 is Leu or Ser; Xaa at position 37 is Phe, Pro, or Ser; Xaa at position 38 is Asn or Ala; Xaa at position 42 is Gly, Ala, Ser, Asp or Asn; Xaa at position 45 is Gin, Val, or Met; Xaa at position 46 is Asp or Ser; Xaa at position 49 is Met, He, Leu or Asp; Xaa at position 50 is Glu or Asp; Xaa at position 51 is Asn Arg or Ser; Xaa at position 55 is Arg, Leu, or Thr; Xaa at position 56 is Pro or Ser; Xaa at position 59 is Glu or Leu; Xaa at position 60 is Ala or Ser; Xaa at position 62 is Asn, Val or Pro; Xaa at position 63 is Arg or His; Xaa at position 65 is Val or Ser; Xaa at position 67 is Ser, Asn, His or Gin; Xaa at position 69 is Gin or Glu; Xaa at position 73 is Ala or Gly; Xaa at position 76 is Ser, Ala or Pro; Xaa at position 79 is Lys, Arg or Ser; Xaa at position 82 is Leu, Glu, Val or Trp; Xaa at position 85 is Leu or Val; Xaa at position 87 is Leu, Ser, Tyr; Xaa at position 88 is Ala or Trp; Xaa at position 91 is Ala or Pro; Xaa at position 93 is Pro or Ser; Xaa at position 95 is His or Thr; Xaa at position 98 is His, He, or Thr; Xaa at position 100 is Lys or Arg; Xaa at position 101 is Asp, Ala or Met; Xaa at position 105 is Asn or Glu; Xaa at position 109 is Arg, Glu or Leu; Xaa at position 112 is Thr or Gin; Xaa at position 116 is Lys, Val, Trp or Ser; Xaa at position 117 is Thr or Ser; Xaa at position 120 is Asn, Gin, or His; Xaa at position 123 is Ala or Glu; with the proviso that from one to three of the amino acids designated by Xaa are different from the corresponding amino acids of native human interleukin-3. 10. The composition of claim 9, wherein said human interleukin-3 mutant polypeptide is of the Formula: 1 5 10 (Metm-Alan)p-Asn Cys Ser Xaa Xaa Xaa Asp Glu Xaa He 15 20 Xaa His Leu Lys Xaa Pro Pro Xaa Pro Xaa Leu Asp Xaa 25 30 35 Xaa Asn Leu Asn Xaa Glu Asp Xaa Xaa He Leu Xaa Glu 40 45 Xaa Asn Leu Arg Xaa Xaa Asn Leu Xaa Xaa Phe Xaa Xaa 50 55 60 Ala Xaa Lys Xaa Leu Xaa Asn Ala Ser Xaa He Glu Xaa 65 70 75 He Leu Xaa Asn Xaa Xaa Pro Cys Xaa Pro Xaa Ala Thr 80 85 Ala Xaa Pro Xaa Arg Xaa Pro He Xaa He Xaa Xaa Gly 90 95 100 Asp Trp Xaa Glu Phe Arg Xaa Lys Leu Xaa Phe Tyr Leu 105 110 Xaa Xaa Leu Glu Xaa Ala Gin Xaa Gin Gin [SEQ ID NO:130] wherein m is 0 or 1; n is 0 or 1; p is 0 or 1; Xaa at position 4 is Asn or He; Xaa at position 5 is Met, Ala or He: Xaa at position 6 is He, Pro or Leu; Xaa at position 9 is He, Ala or Leu; Xaa at position 11 is Thr or His; Xaa at position 15 is Gin, Arg, Val or He; Xaa at position 18 is Leu, Ala, Asn or Arg; Xaa at position 20 is Leu or Ser; Xaa at position 23 is Phe, Pro, or Ser; Xaa at position 24 is Asn or Ala; Xaa at position 28 is Gly, Ala, Ser, Asp or Asn; Xaa at position 31 is Gin, Val, or Met; Xaa at pos_.._on 32 is Asp or Ser; Xaa at position 35 is Met, He or Asp; Xaa at position 36 is Glu or Asp; Xaa at position 37 is Asn, Arg or Ser; Xaa at position 41 is Arg, Leu, or Thr; Xaa at position 42 is Pro or Ser; Xaa at position 45 is Glu or Leu; Xaa at position 46 is Ala or Ser; Xaa at position 48 is Asn, Val or Pro; Xaa at position 49 is Arg or His; Xaa at position 51 is Val or Ser; Xaa at position 53 is Ser, Asn, His or Gin; Xaa at position 55 is Gin or Glu; Xaa at position 59 is Ala or Gly; Xaa at position 62 is Ser, Ala or Pro; Xaa at position 65 is Lys, Arg or Ser; Xaa at position 67 is Leu, Glu, or Val; Xaa at position 68 is Leu, Glu, Val or Trp; Xaa at position 71 is Leu or Val; Xaa at position 73 is Leu, Ser or Tyr; Xaa at position 74 is Ala or Trp; Xaa at position 77 is Ala or Pro; Xaa at position 79 is Pro or Ser; Xaa at position 81 is His or Thr; Xaa at position 84 is His, He, or Thr; Xaa at position 86 is Lys or Arg; Xaa at position 87 is Asp, Ala or Met; Xaa at position 91 is Asn or Glu; Xaa at position 95 is Arg, Glu, Leu; Xaa at position 98 Thr or Gin; Xaa at position 102 is Lys, Val, Trp or Ser; Xaa at position 103 is Thr or Ser; Xaa at position 106 is Asn, Gin, or His; Xaa at position 109 is Ala or Glu; with the proviso that from one to three of 125 Thr, Arg, Ala, Phe, lie or Met; Xaa at position 35 is Leu, Ala, Gly, Asn, Pro, Gin, or Val; Xaa at position 36 is Asp, Leu, or Val; Xaa at position 37 is Phe, Ser, Pro, Trp, or lie; Xaa at position 38 is Asn, or Ala; Xaa at position 40 is Leu, Trp, or Arg; Xaa at position 41 is Asn, Cys, Arg, Leu, His, Met, or Pro; Xaa at position 42 is Gly, Asp, Ser, Cys, Asn, Lys, Thr, Leu, Val, Glu, Phe, Tyr, lie, Met or Ala; Xaa at position 43 is Glu, Asn, Tyr, Leu, Phe, Asp, Ala, Cys, Gin, Arg, Thr, Gly or Ser; Xaa at position 44 is Asp, Ser, Leu, Arg, Lys, Thr, Met, Trp, Glu, Asn, Gin, Ala or Pro; Xaa at position 45 is Gin, Pro, Phe, Val, Met, Leu, Thr, Lys, Trp, Asp, Asn, Arg, Ser, Ala, lie, Glu or His; Xaa at position 46 is Asp, Phe, Ser, Thr, Cys, Glu, Asn, Gin, Lys, His, Ala, Tyr, lie, Val or Gly; Xaa at position 47 is lie, Gly, Val, Ser, Arg, Pro, or His; Xaa at position 48 is Leu, Ser, Cys, Arg, lie. His, Phe, Glu, Lys, Thr, Ala, Met, Val or Asn; Xaa at position 49 is Met, Arg, Ala, Gly, Pro, Asn, His, or Asp; Xaa at position 50 is Glu, Leu, Thr, Asp, Tyr, Lys, Asn, Ser, Ala, lie, Val, His, Phe, Met or Gin; Xaa at position 51 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 52 is Asn, His, Arg, Leu, Gly, Ser, or Thr; Xaa at position 53 is Leu, Thr, Ala, Gly, Glu, Pro, Lys, Ser, or Met; Xaa at position 54 is Arg, Asp, lie, Ser, Val, Thr, Gin, Asn, Lys, His, Ala or Leu; Xaa at position 55 is Arg, Thr, Val, Ser, Leu, or Gly; Xaa at position 56 is Pro, Gly, Cys, Ser, Gin, Glu, Arg, 126 His, Thr, Ala, Tyr, Phe, Leu, Val or Lys; Xaa at position 57 is Asn or Gly; Xaa at position 58 is Leu, Ser, Asp, Arg, Gin, Val, or Cys; Xaa at position 59 is Glu Tyr, His, Leu, Pro, or Arg; Xaa at position 60 is Ala, Ser, Pro, Tyr, Asn, or Thr; Xaa at position 61 is Phe, Asn, Glu, Pro, Lys, Arg, or Ser; Xaa at position 62 is Asn His, Val, Arg, Pro, Thr, Asp, or lie; Xaa at position 63 is Arg, Tyr, Trp, Lys, Ser, His, Pro, or Val; Xaa at position 64 is Ala, Asn, Pro, Ser, or Lys; Xaa at position 65 is Val, Thr, Pro, His, Leu, Phe, or Ser; Xaa at position 66 is Lys, lie, Arg, Val, Asn, Glu, or Ser; Xaa at position 67 is Ser, Ala, Phe, Val, Gly, Asn, lie, Pro, or His; Xaa at position 68 is Leu, Val, Trp, Ser, lie, Phe, Thr, or His; Xaa at position 69 is Gin, Ala, Pro, Thr, Glu, Arg, Trp, Gly, or Leu; Xaa at position 70 is Asn, Leu, Val, Trp, Pro, or Ala; Xaa at position 71 is Ala, Met, Leu, Pro, Arg, Glu, Thr, Gin, Trp, or Asn; Xaa at position 72 is Ser, Glu, Met, Ala, His, Asn, Arg, or Asp; Xaa at position 73 is Ala, Glu, Asp, Leu, Ser, Gly, Thr, or Arg; Xaa at position 74 is lie, Met, Thr, Pro, Arg, Gly, Ala; Xaa at position 75 is Glu, Lys, Gly, Asp, Pro, Trp, Arg, Ser, Gin, or Leu; Xaa at position 76 is Ser, Val, Ala, Asn, Trp, Glu, Pro, Gly, or Asp; Xaa at position 77 is lie, Ser, Arg, Thr, or Leu; Xaa at position 78 is Leu, Ala, Ser, Glu, Phe, Gly, or 123 the amino acids designated by Xaa are different from the corresponding amino acids of native (15- 125)human interleukin-3. 11. The composition of claim 1 , 2 , or 5 wherein said CSF is selected from the group consisting of G-CSF and GM-CSF : 12 . A method of increasing multi-lineage hematopoietic cell production in a mammal in need thereof comprising administering a pharmaceutically effective amount of a human interleukin-3 mutant polypeptide of the Formula : Ala Pro Met Thr Gin Thr Thr Ser Leu Lys Thr Ser Trp Val Asn 1 5 10 15 Cys Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 20 25 30 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Asn Xaa Xaa Xaa Xaa Xaa Xaa 35 40 45 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 50 55 60 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 65 70 75 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 80 85 90 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 95 100 105 Xaa Phe Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 110 115 120 124 Xaa Xaa Xaa Gin Gin Thr Thr Leu Ser Leu Ala lie Phe 125 130 [SEQ ID NO:15] wherein Xaa at position 17 is Ser, Lys, Gly, Asp, Met, Gin, or Arg; Xaa at position 18 is Asn, His, Leu, lie, Phe, Arg, or Gin; Xaa at position 19 is Met, Phe, lie, Arg, Gly, Ala, or Cys; Xaa at position 20 is lie, Cys, Gin, Glu, Arg, Pro, or Ala; Xaa at position 21 is Asp, Phe, Lys, Arg, Ala, Gly, Glu, Gin, Asn, Thr, Ser or Val; Xaa at position 22 is Glu, Trp, Pro, Ser, Ala, His, Asp, Asn, Gin, Leu, Val or Gly; Xaa at position 23 is lie, Val, Ala, Leu, Gly, Trp, Lys, Phe, Leu, Ser, or Arg; Xaa at position 24 is lie, Gly, Val, Arg, Ser, Phe, or Leu; Xaa at position 25 is Thr, His, Gly, Gin, Arg, Pro, or Ala; Xaa at position 26 is His, Thr, Phe, Gly, Arg, Ala, or Trp; Xaa at position 27 is Leu, Gly, Arg, Thr, Ser, or Ala; Xaa at position 28 is Lys, Arg, Leu, Gin, Gly, Pro, Val or Trp; Xaa at position 29 is Gin, Asn, Leu, Pro, Arg, or Val; Xaa at position 30 is Pro, His, Thr, Gly, Asp, Gin, Ser, Leu, or Lys; Xaa at position 31 is Pro, Asp, Gly, Ala, Arg, Leu, or Gin; Xaa at position 32 is Leu, Val, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 33 is Pro, Leu, Gin, Ala, Thr, or Glu; Xaa at position 34 is Leu, Val, Gly, Ser, Lys, Glu, Gin, Arg; Xaa at position 79 is Lys, Thr, Asn, Met, Arg, lie, Gly, or Asp; Xaa at position 80 is Asn, Trp, Val, Gly, Thr, Leu, Glu, or Arg; Xaa at position 81 is Leu, Gin, Gly, Ala, Trp, Arg, Val, or Lys; Xaa at position 82 is Leu, Gin, Lys, Trp, Arg, Asp, Glu, Asn, His, Thr, Ser, Ala, Tyr, Phe, lie, Met or Val; Xaa at position 83 is Pro, Ala, Thr, Trp, Arg, or Met; Xaa at position 84 is Cys, Glu, Gly, Arg, Met, or Val; Xaa at position 85 is Leu, Asn, Val, or Gin; Xaa at position 86 is Pro, Cys, Arg, Ala, or Lys; Xaa at position 87 is Leu, Ser, Trp, or Gly; Xaa at position 88 is Ala, Lys, Arg, Val, or Trp; Xaa at position 89 is Thr, Asp, Cys, Leu, Val, Glu, His, Asn, or Ser; Xaa at position 90 is Ala, Pro, Ser, Thr, Gly, Asp, lie, or Met; Xaa at position 91 is Ala, Pro, Ser, Thr, Phe, Leu, Asp, or His; Xaa at position 92 is Pro, Phe, Arg, Ser, Lys, His, Ala, Gly, lie or Leu; Xaa at position 93 is Thr, Asp, Ser, Asn, Pro, Ala, Leu, or Arg; Xaa at position 94 is Arg, lie, Ser, Glu, Leu, Val, Gin, Lys, His, Ala, or Pro; Xaa at position 95 is His, Gin, Pro, Arg, Val, Leu, Gly, Thr, Asn, Lys, Ser, Ala, Trp, Phe, lie, or Tyr; Xaa at position 96 is Pro, Lys, Tyr, Gly, lie, or Thr; Xaa at position 97 is lie, Val, Lys, Ala, or Asn; Xaa at position 98 is His, lie, Asn, Leu, Asp, Ala, Thr, Glu, Gin, Ser, Phe, Met, Val, Lys, Arg, Tyr or Pro; Xaa at position 99 is lie, Leu, Arg, Asp, Val, Pro, Gin, Gly, Ser, Phe, or His; Xaa at position 100 is Lys, Tyr, Leu, His, Arg, lie, Ser, Gin, or Pro; Xaa at position 101 is Asp, Pro, Met, Lys, His, Thr, Val, Tyr, Glu, Asn, Ser, Ala, Gly, lie, Leu, or Gin; Xaa at position 102 is Gly, Leu, Glu, Lys, Ser, Tyr, or Pro; Xaa at position 103 is Asp, or Ser; Xaa at position 104 is Trp, Val, Cys, Tyr, Thr, Met, Pro, Leu, Gin, Lys, Ala, Phe, or Gly; Xaa at position 105 is Asn, Pro, Ala, Phe, Ser, Trp, Gin, Tyr, Leu, Lys, lie, Asp, or His; Xaa at position 106 is Glu, Ser, Ala, Lys, Thr, lie, Gly, or Pro; Xaa at position 108 is Arg, Lys, Asp, Leu, Thr, lie, Gin, His, Ser, Ala or Pro; Xaa at position 109 is Arg, Thr, Pro, Glu, Tyr, Leu, Ser, or Gly; Xaa at position 110 is Lys, Ala, Asn, Thr, Leu, Arg, Gin, His, Glu, Ser, Ala, or Trp; Xaa at position 111 is Leu, lie, Arg, Asp, or Met; Xaa at position 112 is Thr, Val, Gin, Tyr, Glu, His, Ser, or Phe; Xaa at position 113 is Phe, Ser, Cys, His, Gly, Trp, Tyr, Asp, Lys, Leu, lie, Val or Asn; Xaa at position 114 is Tyr, Cys, His, Ser, Trp, Arg, or Leu; Xaa at position 115 is Leu, Asn, Val, Pro, Arg, Ala, His, Thr, Trp, or Met; Xaa at position 116 is Lys, Leu, Pro, Thr, Met, Asp, Val, Glu, Arg, Trp, Ser, Asn, His, Ala, Tyr, Phe, Gin, or lie; Xaa at position 117 is Thr, Ser, Asn, lie, Trp, Lys, or Pro; Xaa at position 118 is Leu, Ser, Pro, Ala, Glu, Cys, Asp, or Tyr; Xaa at position 119 is Glu, Ser, Lys, Pro, Leu, Thr, Tyr, or Arg; Xaa at position 120 is Asn, Ala, Pro, Leu, His, Val, or Gin; Xaa at position 121 is Ala, Ser, lie, Asn, Pro, Lys, Asp, or Gly; Xaa at position 122 is Gin, Ser, Met, Trp, Arg, Phe, Pro, His, lie, Tyr, or Cys; Xaa at position 123 is Ala, Met, Glu, His, Ser, Pro, Tyr, or Leu; and which can additionally have Met- preceding the amino acid in position 1; and wherein from 1 to 14 amino acids can be deleted from the N-terminus and/or from 1 to 15 amino acids can be deleted from the C-terminus; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native (1- 133) human interleukin-3; and A colony stimulating factor. 13. A method of increasing multi-lineage hematopoietic cell production in a mammal in need thereof comprising administering a pharmaceutically effective amount of human interleukin-3 mutant polypeptide of the Formula: Ala Pro Met Thr Gin Thr Thr Ser Leu Lys Thr Ser Trp Val Asn 1 5 10 15 Cys Xaa Xaa Xaa lie Xaa Glu Xaa Xaa Xaa Xaa Leu Lys Xaa Xaa 20 25 30 Xaa Xaa Xaa Xaa Xaa Asp Xaa Xaa Asn Leu Asn Xaa Glu Xaa Xaa 35 40 45 Xaa lie Leu Met Xaa Xaa Asn Leu Xaa Xaa Xaa Asn Leu Glu Xaa 50 55 60 Phe Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Asn Xaa Xaa Xaa lie Glu 65 70 75 Xaa Xaa Leu Xaa Xaa Leu Xaa Xaa Cys Xaa Pro Xaa Xaa Thr Ala 80 85 90 Xaa Pro Xaa Arg Xaa Xaa Xaa Xaa Xaa Xaa Xaa Gly Asp Xaa Xaa 95 100 105 Xaa Phe Xaa Xaa Lys Leu Xaa Phe Xaa Xaa Xaa Xaa Leu Glu Xaa 110 115 120 Xaa Xaa Xaa Gin Gin Thr Thr Leu Ser Leu Ala lie Phe 125 130 [SEQ ID NO:17] wherein Xaa at position 17 is Ser, Gly, Asp, Met, or Gin; Xaa at position 18 is Asn, His, or lie; Xaa at position 19 is Met or lie; Xaa at position 21 is Asp or Glu; Xaa at position 23 is lie, Ala, Leu, or Gly; Xaa at position 24 is lie, Val, or Leu; Xaa at position 25 is Thr, His, Gin, or Ala; Xaa at position 26 is His or Ala; Xaa at position 29 is Gin, Asn, or Val; Xaa at position 30 is Pro, Gly, or Gin; Xaa at position 31 is Pro, Asp, Gly, or Gin; Xaa at position 32 is Leu, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 33 is Pro or Glu; Xaa at position 34 is Leu, Val, Gly, Ser, Lys, Ala, Arg, Gin, Glu, lie, Phe, Thr or Met; Xaa at position 35 is Leu, Ala, Asn, Pro, Gin, or Val; Xaa at position 37 is Phe, Ser, Pro, or Trp; Xaa at position 38 is Asn or Ala; Xaa at position 42 is Gly, Asp, Ser, Cys, Ala, Asn, lie, Leu, Met, Tyr or Arg; Xaa at position 44 is Asp or Glu; Xaa at position 45 is Gin, Val, Met, Leu, Thr, Ala, Asn, Glu, Ser or Lys; Xaa at position 46 is Asp, Phe, Ser, Thr, Ala, Asn Gin, Glu, His, He, Lys, Tyr, Val or Cys; Xaa at position 50 is Glu, Ala, Asn, Ser or Asp; Xaa at position 51 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 54 is Arg or Ala; Xaa at position 55 is Arg, Thr, Val, Leu, or Gly; Xaa at position 56 is Pro, Gly, Ser, Gin, Ala, Arg, Asn, Glu, Leu, Thr, Val or Lys; Xaa at position 60 is Ala or Ser; Xaa at position 62 is Asn, Pro, Thr, or lie; Xaa at position 63 is Arg or Lys; Xaa at position 64 is Ala or Asn; Xaa at position 65 is Val or Thr; Xaa at position 66 is Lys or Arg; Xaa at position 67 is Ser, Phe, or His; Xaa at position 68 is Leu, He, Phe, or His; Xaa at position 69 is Gin, Ala, Pro, Thr, Glu, Arg, or Gly; Xaa at position 71 is Ala, Pro, or Arg; Xaa at position 72 is Ser, Glu, Arg, or Asp; Xaa at position 73 is Ala or Leu; Xaa at position 76 is Ser, Val, Ala, Asn, Glu, Pro, or Gly; Xaa at position 77 is He or Leu; Xaa at position 79 is Lys, Thr, Gly, Asn, Met, Arg, He, Gly, or Asp; Xaa at position 80 is Asn, Gly, Glu, or Arg; Xaa at position 82 is Leu, Gin, Trp, Arg, Asp, Ala, Asn, Glu, His, He, Met, Phe, Ser, Thr, Tyr or Val; Xaa at position 83 is Pro or Thr; Xaa at position 85 is Leu or Val; Xaa at position 87 is Leu or Ser; Xaa at position 88 is Ala or Trp; Xaa at position 91 is Ala or Pro; Xaa at position 93 is Thr, Asp, Ser, Pro, Ala, Leu, or Arg; Xaa at position 95 is His, Pro, Arg, Val, Leu, Gly, Asn, Phe, Ser or Thr; Xaa at position 96 is Pro or Tyr; Xaa at position 97 is He or Val; Xaa at position 98 is His, He, Asn, Leu, Ala, Thr, Leu, Arg, Gin, Leu, Lys, Met, Ser, Tyr, Val or Pro; Xaa at position 99 is He, Leu, or Val; Xaa at position 100 is Lys, Arg, He, Gin, Pro, or Ser; Xaa at position 101 is Asp, Pro, Met, Lys, His, Thr, Pro, Asn, He, Leu or Tyr; Xaa at position 104 is Trp or Leu; Xaa at position 105 is Asn, Pro, Ala, Ser, Trp, Gin, Tyr, Leu, Lys, He, Asp, or His; Xaa at position 106 is Glu or Gly; Xaa at position 108 is Arg, Ala, or Ser; Xaa at position 109 is Arg, Thr, Glu, Leu, or Ser; Xaa at position 112 is Thr, Val, or Gin; Xaa at position 114 is Tyr or Trp; Xaa at position 115 is Leu or Ala; Xaa at position 116 is Lys, Thr, Val, Trp, Ser, Ala, His, Met, Phe, Tyr or lie; Xaa at position 117 is Thr or Ser; Xaa at position 120 is Asn, Pro, Leu, His, Val, or Gin; Xaa at position 121 is Ala, Ser, He, Asn, Pro, Asp, or Gly; Xaa at position 122 is Gin, Ser, Met, Trp, Arg, Phe, Pro, His, He, Tyr, or Cys; Xaa at position 123 is Ala, Met, Glu, His, Ser, Pro, Tyr, or Leu; and which can additionally have Met- preceding the amino acid in position 1; and wherein from 1 to 14 amino acids can be deleted from the N-terminus and/or from 1 to 15 amino acids can be deleted from the C-terminus; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native (1- 133) uman interleukin-3; and A colony stimulating factor . 14. The method of claim 13, wherein said human interleukin-3 mutant polypeptide is of the Formula: Ala Pro Met Thr Gin Thr Thr Ser Leu Lys Thr Ser Trp Val Asn 1 5 10 15 Cys Xaa Xaa Met He Asp Glu Xaa He Xaa Xaa Leu Lys Xaa Xaa 20 25 30 Pro Xaa Pro Xaa Xaa Asp Phe Xaa Asn Leu Asn Xaa Glu Asp Xaa 35 40 45 Xaa He Leu Met Xaa Xaa Asn Leu Arg Xaa Xaa Asn Leu Glu Ala 50 55 60 Phe Xaa Arg Xaa Xaa Lys Xaa Xaa Xaa Asn Ala Ser Ala He Glu 65 70 75 Xaa Xaa Leu Xaa Xaa Leu Xaa Pro Cys Leu Pro Xaa Xaa Thr Ala 80 85 90 Xaa Pro Xaa Arg Xaa Pro He Xaa Xaa Xaa Xaa Gly Asp Trp Xaa 95 100 105 Glu Phe Xaa Xaa Lys Leu Xaa Phe Tyr Leu Xaa Xaa Leu Glu Xaa 110 115 120 Xaa Xaa Xaa Gin Gin Thr Thr Leu Ser Leu Ala He Phe 125 130 [SEQ ID NO:18] wherein Xaa at position 17 is Ser, Gly, Asp, or Gin; Xaa at position 18 is Asn, His, or lie; Xaa at position 23 is He, Ala, Leu, or Gly; Xaa at position 25 is Thr, His, or Gin; Xaa at position 26 is His or Ala; Xaa at position 29 is Gin or Asn; Xaa at position 30 is Pro or Gly; Xaa at position 32 is Leu, Arg, Asn, or Ala; Xaa at position 34 is Leu, Val, Ser, Ala, Arg, Gin, Glu, He, Phe, Thr, or Met; Xaa at position 35 is Leu, Ala, Asn, or Pro; Xaa at position 38 is Asn or Ala; Xaa at position 42 is Gly, Asp, Ser, Ala, Asn, He, Leu, Met, Tyr or Arg; Xaa at position 45 is Gin, Val, Met, Leu, Ala, Asn, Glu, or Lys; Xaa at position 46 is Asp, Phe, Ser, Gin, Glu, His, Val or Thr; Xaa at position 50 is Glu Asn, Ser or Asp; Xaa at position 51 is Asn, Arg, Pro, Thr, or His; Xaa at position 55 is Arg, Leu, or Gly; Xaa at position 56 is Pro, Gly, Ser, Ala, Asn, Val, Leu or Gin; Xaa at position 62 is Asn, Pro, or Thr; Xaa at position 64 is Ala or Asn; Xaa at position 65 is Val or Thr; Xaa at position 67 is Ser or Phe; Xaa at position 68 is Leu or Phe; Xaa at position 69 is Gin, Ala, Glu, or Arg; Xaa at position 76 is Ser, Val, Asn, Pro, or Gly; Xaa at position 77 is He or Leu; Xaa at position 79 is Lys, Gly, Asn, Met, Arg, He, or Gly; Xaa at position 80 is Asn, Gly, Glu, or Arg; Xaa at position 82 is Leu, Gin, Trp, Arg, Asp, Asn, Glu, His, Met, Phe, Ser, Thr, Tyr or Val; Xaa at position 87 is Leu or Ser; Xaa at position 88 is Ala or Trp; Xaa at position 91 is Ala or Pro; Xaa at position 93 is Thr, Asp, or Ala; Xaa at position 95 is His, Pro, Arg, Val, Gly, Asn, Ser or Thr; Xaa at position 98 is His, He, Asn, Ala, Thr, Gin, Glu, Lys, Met, Ser, Tyr, Val or Leu; Xaa at position 99 is He or Leu; Xaa at position 100 is Lys or Arg; Xaa at position 101 is Asp, Pro, Met, Lys, Thr, His, Pro, Asn, He, Leu or Tyr; Xaa at position 105 is Asn, Pro, Ser, He or Asp; Xaa at position 108 is Arg, Ala, or Ser; Xaa at position 109 is Arg, Thr, Glu, Leu, or Ser; Xaa at position 112 is Thr or Gin; Xaa at position 116 is Lys, Val, Trp, Ala, His, Phe, Tyr or lie; Xaa at position 117 is Thr or Ser; Xaa at position 120 is Asn, Pro, Leu, His, Val, or Gin; Xaa at position 121 is Ala, Ser, He, Pro, or Asp; Xaa at position 122 is Gin, Met, Trp, Phe, Pro, His, He, or Tyr; Xaa at position 123 is Ala, Met, Glu, Ser, or Leu; and which can additionally have Met- preceding the amino acid in position 1; and wherein from 1 to 14 amino acids can be deleted from the N-terminus and/or from 1 to 15 amino acids can be deleted from the C-terminus; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native (1- 133)human interleukin-3. 15. The method of claim 14 , wherein said human interleukin-3 mutant polypeptide is of the Formula : Xaa at position 42 is Gly, Asp, Ser, He, Leu, Met, Tyr, or Ala; Xaa at position 45 is Gin, Val, Met or Asn; Xaa at position 46 is Asp, Ser, Gin, His or Val; Xaa at position 50 is Glu or Asp; Xaa at position 51 is Asn, Pro or Thr; Xaa at position 62 is Asn or Pro; Xaa at position 76 is Ser, or Pro; Xaa at position 82 is Leu, Trp, Asp, Asn Glu, His, Phe, Ser or Tyr; Xaa at position 95 is His, Arg, Thr, Asn or Ser; Xaa at position 98 is His, He, Leu, Ala, Gin, Lys, Met, Ser, Tyr or Val; Xaa at position 100 is Lys or Arg; Xaa at position 101 is Asp, Pro, His, Asn, He or Leu; Xaa at position 105 is Asn, or Pro; Xaa at position 108 is Arg, Ala, or Ser; Xaa at position 116 is Lys, Val, Trp, Ala, His, Phe, or Tyr; Xaa at position 121 is Ala, or lie; Xaa at position 122 is Gin, or He; and Xaa at position 123 is Ala, Met or Glu. 16. A method of increasing multi-lineage hematopoietic cell production in a mammal in need thereof comprising administering a pharmaceutically effective amount of a human interleukin-3 mutant polypeptide of the Formula: Asn Cys Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 1 5 10 15 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Asn Xaa Xaa Xaa Xaa Xaa 20 25 30 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 35 40 45 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 50 55 60 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 65 70 75 Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 80 85 90 Xaa Xaa Phe Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa 95 100 105 Xaa Xaa Xaa Xaa Gin Gin [SEQ ID NO:19] 110 wherein Xaa at position 3 is Ser, Lys, Gly, Asp, Met, Gin, or Arg Xaa at position 4 is Asn, His, Leu, He, Phe, Arg, or Gin Xaa at position 5 is Met, Phe, He, Arg, Gly, Ala, or Cys Xaa at position 6 is He, Cys, Gin, Glu, Arg, Pro, or Ala Xaa at position 7 is Asp, Phe, Lys, Arg, Ala, Gly, Glu, Gin, Asn, Thr, Ser or Val; Xaa at position 8 is Glu, Trp, Pro, Ser, Ala, His, Asp, Asn, Gin, Leu, Val, or Gly; Xaa at position 9 is He, Val, Ala, Leu, Gly, Trp, Lys, Phe, Leu, Ser, or Arg; Xaa at position 10 is He, Gly, Val, Arg, Ser, Phe, or Leu; Xaa at position 11 is Thr, His, Gly, Gin, Arg, Pro, or Ala; Xaa at position 12 is His, Thr, Phe, Gly, Arg, Ala, or Trp; Xaa at position 13 is Leu, Gly, Arg, Thr, Ser, or Ala; Xaa at position 14 is Lys, Arg, Leu, Gin, Gly, Pro, Val or Trp; Xaa at position 15 is Gin, Asn, Leu, Pro, Arg, or Val; Xaa at position 16 is Pro, His, Thr, Gly, Asp, Gin, Ser, Leu, or Lys; Xaa at position 17 is Pro, Asp, Gly, Ala, Arg, Leu, or Gin; Xaa at position 18 is Leu, Val, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 19 is Pro, Leu, Gin, Ala, Thr, or Glu; Xaa at position 20 is Leu, Val, Gly, Ser, Lys, Glu, Gin, Thr, Arg, Ala, Phe, He or Met; Xaa at position 21 is Leu, Ala, Gly, Asn, Pro, Gin, or Val; Xaa at position 22 is Asp, Leu, or Val; Xaa at position 23 is Phe, Ser, Pro, Trp, or lie; Xaa at position 24 is Asn, or Ala; Xaa at position 26 is Leu, Trp, or Arg; Xaa at position 27 is Asn, Cys, Arg, Leu, His, Met, Pro; Xaa at position 28 is Gly, Asp, Ser, Cys, Ala, Lys, Asn, Thr, Leu, Val, Glu, Phe, Tyr, He or Met; Xaa at position 29 is Glu, Asn, Tyr, Leu, Phe, Asp, Ala, Cys, Gin, Arg, Thr, Gly or Ser; Xaa at position 30 is Asp, Ser, Leu, Arg, Lys, Thr, et, Trp, Glu, Asn, Gin, Ala or Pro; Xaa at position 31 is Gin, Pro, Phe, Val, Met, Leu, Thr, Lys, Asp, Asn, Arg, Ser, Ala, He, Glu, His or Trp; Xaa at position 32 is Asp, Phe, Ser ' , Thr, Cys, Glu, Asn, Gin, Lys, His, Ala, Tyr, He, Val or Gly; Xaa at position 33 is He, Gly, Val, Ser, Arg, Pro, or His; Xaa at position 34 is Leu, Ser, Cys, Arg, He, His, Phe, Glu, Lys, Thr, Ala, Met, Val or Asn; Xaa at position 35 is Met, Arg, Ala, Gly, Pro, Asn, His, or Asp; Xaa at position 36 is Glu, Leu, Thr, Asp, Tyr, Lys, Asn, Ser, Ala, He, Val, His, Phe, Met or Gin; Xaa at position 37 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 38 is Asn, His, Arg, Leu, Gly, Ser, or Thr; Xaa at position 39 is Leu, Thr, Ala, Gly, Glu, Pro, Lys, Ser, Met, or; Xaa at position 40 is Arg, Asp, He, Ser, Val, Thr, Gin, Asn, Lys, His, Ala or Leu; Xaa at position 41 is Arg, Thr, Val, Ser, Leu, or Gly; Xaa at position 42 is Pro, Gly, Cys, Ser, Gin, Glu, Arg, His, Thr, Ala, Tyr, Phe, Leu, Val or Lys; Xaa at position 43 is Asn or Gly; Xaa at position 44 is Leu, Ser, Asp, Arg, Gin, Val, or Cys; Xaa at position 45 is Glu Tyr, His, Leu, Pro, or Arg; Xaa at position 46 is Ala, Ser, Pro, Tyr, Asn, or Thr; Xaa at position 47 is Phe, Asn, Glu, Pro, Lys, Arg, or Ser; Xaa at position 48 is Asn, His, Val, Arg, Pro, Thr, Asp, or lie; Xaa at position 49 is Arg, Tyr, Trp, Lys, Ser, His, Pro, or Val; Xaa at position 50 is Ala, Asn, Pro, Ser, or Lys; Xaa at position 51 is Val, Thr, Pro, His, Leu, Phe, or Ser; Xaa at position 52 is Lys, He, Arg, Val, Asn, Glu, or Ser; Xaa at position 53 is Ser, Ala, Phe, Val, Gly, Asn, He, Pro, or His; Xaa at position 54 is Leu, Val, Trp, Ser, He, Phe, Thr, or His; Xaa at position 55 is Gin, Ala, Pro, Thr, Glu, Arg, Trp, Gly, or Leu; Xaa at position 56 is Asn, Leu, Val, Trp, Pro, or Ala; Xaa at position 57 is Ala, Met, Leu, Pro, Arg, Glu, Thr, Gin, Trp, or Asn; Xaa at position 58 is Ser, Glu, Met, Ala, His, Asn, Arg, or Asp; Xaa at position 59 is Ala, Glu, Asp, Leu, Ser, Gly, Thr, or Arg; Xaa at position 60 is He, Met, Thr, Pro, Arg, Gly, Ala; Xaa at position 61 is Glu, Lys, Gly, Asp, Pro, Trp, Arg, Ser, Gin, or Leu; Xaa at position 62 is Ser, Val, Ala, Asn, Trp, Glu, Pro, Gly, or Asp; Xaa at position 63 is He, Ser, Arg, Thr, or Leu; Xaa at position 64 is Leu, Ala, Ser, Glu, Phe, Gly, or Arg; Xaa at position 65 is Lys, Thr, Gly, Asn, Met, Arg, He, or Asp; Xaa at position 66 is Asn, Trp, Val, Gly, Thr, Leu, Glu, or Arg; Xaa at position 67 is Leu, Gin, Gly, Ala, Trp, Arg, Val, or Lys; Xaa at position 68 is Leu, Gin, Lys, Trp, Arg, Asp, Glu, Asn, His, Thr, Ser, Ala, Tyr, Phe, He, Met or Val; Xaa at position 69 is Pro, Ala, Thr, Trp, Arg, or Met; Xaa at position 70 is Cys, Glu, Gly, Arg, Met, or Val; Xaa at position 71 is Leu, Asn, Val, or Gin; Xaa at position 72 is Pro, Cys, Arg, Ala, or Lys; Xaa at position 73 is Leu, Ser, Trp, or Gly; Xaa at position 74 is Ala, Lys, Arg, Val, or Trp; Xaa at position 75 is Thr, Asp, Cys, Leu, Val, Glu, His, Asn, or Ser; Xaa at position 76 is Ala, Pro, Ser, Thr, Gly, Asp, He, or Met; Xaa at position 77 is Ala, Pro, Ser, Thr, Phe, Leu, Asp, or His; Xaa at position 78 is Pro, Phe, Arg, Ser, Lys, His, Ala, Gly, He or Leu; Xaa at position 79 is Thr, Asp, Ser, Asn, Pro, Ala, Leu, or Arg; Xaa at position 80 is Arg, He, Ser, Glu, Leu, Val, Gin, Lys, His, Ala or Pro; Xaa at position 81 is His, Gin, Pro, Arg, Val, Leu, Gly, Thr, Asn, Lys, Ser, Ala, Trp, Phe, He or Tyr; Xaa at position 82 is Pro, Lys, Tyr, Gly, He, or Thr; Xaa at position 83 is He, Val, Lys, Ala, or Asn; Xaa at position 84 is His, He, Asn, Leu, Asp, Ala, Thr, Glu, Gin, Ser, Phe, Met, Val, Lys, Arg, Tyr or Pro; Xaa at position 85 is He, Leu, Arg, Asp, Val, Pro, Gin, Gly, Ser, Phe, or His; Xaa at position 86 is Lys, Tyr, Leu, His, Arg, He, Ser, Gin, Pro; Xaa at position 87 is Asp, Pro, Met, Lys, His, Thr, Val, Tyr, Glu, Asn, Ser, Ala, Gly, He, Leu or Gin; Xaa at position 88 is Gly, Leu, Glu, Lys, Ser, Tyr, or Pro; Xaa at position 89 is Asp, or Ser; Xaa at position 90 is Trp, Val, Cys, Tyr, Thr, Met, Pro, Leu, Gin, Lys, Ala, Phe, or Gly; Xaa at position 91 is Asn, Pro, Ala, Phe, Ser, Trp, Gin, Tyr, Leu, Lys, He, Asp, or His; Xaa at position 92 is Glu, Ser, Ala, Lys, Thr, He, Gly, or Pro; Xaa at position 94 is Arg, Lys, Asp, Leu, Thr, He, Gin, His, Ser, Ala, or Pro; Xaa at position 95 is Arg, Thr, Pro, Glu, Tyr, Leu, Ser, or Gly; Xaa at position 96 is Lys, Asn, Thr, Leu, Gin, Arg, His, Glu, Ser, Ala or Trp; Xaa at position 97 is Leu, He, Arg, Asp, or Met; Xaa at position 98 is Thr, Val, Gin, Tyr, Glu, His, Ser, or Phe; Xaa at position 99 is Phe, Ser, Cys, His, Gly, Trp, Tyr, Asp, Lys, Leu, He, Val or Asn; Xaa at position 100 is Tyr, Cys, His, Ser, Trp, Arg, or Leu; Xaa at position 101 is Leu, Asn, Val, Pro, Arg, Ala, His, Thr, Trp, or Met; Xaa at position 102 is Lys, Leu, Pro, Thr, Met, Asp, Val, Glu, Arg, Trp, Ser, Asn, His, Ala, Tyr, Phe, Gin, or lie; Xaa at position 103 is Thr, Ser, Asn, He, Trp, Lys, or Pro; Xaa at position 104 is Leu, Ser, Pro, Ala, Glu, Cys, Asp, or Tyr; Xaa at position 105 is Glu, Ser, Lys, Pro, Leu, Thr, Tyr, or Arg; Xaa at position 106 is Asn, Ala, Pro, Leu, His, Val, or Gin; Xaa at position 107 is Ala, Ser, He, Asn, Pro, Lys, Asp, or Gly; Xaa at position 108 is Gin, Ser, Met, Trp, Arg, Phe, Pro, His, He, Tyr, or Cys; Xaa at position 109 is Ala, Met, Glu, His, Ser, Pro, Tyr, or Leu; and which can additionally have Met- or Met-Ala- preceding the amino acid in position 1; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding native amino acids of (1-133) human interleukin-3; and A pharmaceutically effective amount of a colony stimulating factor . 17. The method of claim 16, wherein said human interleukin-3 mutant polypeptide is of the Formula: Asn Cys Xaa Xaa Xaa He Xaa Glu Xaa Xaa Xaa Xaa Leu Lys Xaa 1 5 10 15 Xaa Xaa Xaa Xaa Xaa Xaa Asp Xaa Xaa Asn Leu Asn Xaa Glu Xaa 20 25 30 Xaa Xaa He Leu Met Xaa Xaa Asn Leu Xaa Xaa Xaa Asn Leu Glu 35 40 45 Xaa Phe Xaa Xaa Xaa Xaa Xaa Xaa Xaa Xaa Asn Xaa Xaa Xaa He 50 55 60 Glu Xaa Xaa Leu Xaa Xaa Leu Xaa Xaa Cys Xaa Pro Xaa Xaa Thr 65 70 75 Ala Xaa Pro Xaa Arg Xaa Xaa Xaa Xaa Xaa Xaa Xaa Gly Asp Xaa 80 85 90 Xaa Xaa Phe Xaa Xaa Lys Leu Xaa Phe Xaa Xaa Xaa Xaa Leu Glu 95 100 105 Xaa Xaa Xaa Xaa Gin Gin [SEQ ID NO:21] 110 wherein Xaa at position 3 is Ser, Gly, Asp, Met, or Gin; Xaa at position 4 is Asn, His, or lie; Xaa at position 5 is Met or lie; Xaa at position 7 is Asp or Glu; Xaa at position 9 is He, Ala, Leu, or Gly; Xaa at position 10 is He, Val, or Leu; Xaa at position 11 is Thr, His, Gin, or Ala; Xaa at position 12 is His or Ala; Xaa at position 15 is Gin, Asn, or Val; Xaa at position 16 is Pro, Gly, or Gin; Xaa at position 17 is Pro, Asp, Gly, or Gin; Xaa at position 18 is Leu, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 19 is Pro or Glu; Xaa at position 20 is Leu, Val, Gly, Ser, Lys, Ala, Arg, Gin, Glu, He, Phe, Thr or Met; Xaa at position 21 is Leu, Ala, Asn, Pro, Gin, or Val; Xaa at position 23 is Phe, Ser, Pro, or Trp; Xaa at position 24 is Asn or Ala; Xaa at position 28 is Gly, Asp, Ser, Cys, Ala, Asn, He, Leu, Met Tyr or Arg; Xaa at position 30 is Asp or Glu; Xaa at position 31 is Gin, Val, Met, Leu, Thr, Ala, Asn, Glu, Ser or Lys; Xaa at position 32 is Asp, Phe, Ser, 1. . , Ala, Asn, Gin, Glu, His, He, Lys, Tyr, Val or Cys; Xaa at position 36 is Glu, Ala, Asn, Ser or Asp; Xaa at position 37 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 40 is Arg or Ala; Xaa at position 41 is Arg, Thr, Val, Leu, or Gly; Xaa at position 42 is Pro, Gly, Ser, Gin, Ala, Arg, Asn, Glu, Leu, Thr, Val or Lys; Xaa at position 46 is Ala or Ser; Xaa at position 48 is Asn, Pro, Thr, or lie; Xaa at position 49 is Arg or Lys; Xaa at position 50 is Ala or Asn; Xaa at position 51 is Val or Thr; Xaa at position 52 is Lys or Arg; Xaa at position 53 is Ser, Phe, or His; Xaa at position 54 is Leu, He, Phe, or His; Xaa at position 55 is Gin, Ala, Pro, Thr, Glu, Arg, or Gly; Xaa at position 57 is Ala, Pro, or Arg; Xaa at position 58 is Ser, Glu, Arg, or Asp; Xaa at position 59 is Ala or Leu; Xaa at position 62 is Ser, Val, Ala, Asn, Glu, Pro, or Gly; Xaa at position 63 is He or Leu; Xaa at position 65 is Lys, Thr, Gly, Asn, Met, Arg, He, Gly, or Asp; Xaa at position 66 is Asn, Gly, Glu, or Arg; Xaa at position 68 is Leu, Gin, Trp, Arg, Asp, Ala, Asn, Glu, His, He, Met, Phe, Ser, Thr, Tyr or Val; Xaa at position 69 is Pro or Thr; Xaa at position 71 is Leu or Val; Xaa at position 73 is Leu or Ser; Xaa at position 74 is Ala or Trp; Xaa at position 77 is Ala or Pro; Xaa at position 79 is Thr, Asp, Ser, Pro, Ala, Leu, or Arg; Xaa at position 81 is His, Pro, Arg, Val, Leu, Gly, Asn, Phe, Ser or Thr; Xaa at position 82 is Pro or Tyr; Xaa at position 83 is He or Val; Xaa at position 84 is His, He, Asn, Leu, Ala, Thr, Leu, Arg, Gin, Leu, Lys, Met, Ser, Tyr, Val or Pro; Xaa at position 85 is He, Leu, or Val; Xaa at position 86 is Lys, Arg, He, Gin, Pro, or Ser; Xaa at position 87 is Asp, Pro, Met, Lys, His, Thr, Asn, He, Leu or Tyr; Xaa at position 90 is Trp or Leu; Xaa at position 91 is Asn, Pro, Ala, Ser, Trp, Gin, Tyr, Leu, Lys, He, Asp, or His; Xaa at position 92 is Glu, or Gly; Xaa at position 94 is Arg, Ala, or Ser; Xaa at position 95 is Arg, Thr, Glu, Leu, or Ser; Xaa at position 98 is Thr, Val, or Gin; Xaa at position 100 is Tyr or Trp; Xaa at position 101 is Leu or Ala; Xaa at position 102 is Lys, Thr, Val, Trp, Ser, Ala, His, Met, Phe, Tyr or lie; Xaa at position 103 is Thr or Ser; Xaa at position 106 is Asn, Pro, Leu, His, Val, or Gin; Xaa at position 107 is Ala, Ser, He, Asn, Pro, Asp, or Gly; Xaa at position 108 is Gin, Ser, Met, Trp, Arg, Phe, Pro, His, He, Tyr, or Cys; Xaa at position 109 is Ala, Met, Glu, His, Ser, Pro, Tyr, or Leu; which can additionally have Met- or Met-Ala- preceding the amino acid in position 1 ; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native human interleukin-3 . 18. The method of claim 17 , wherein said human interleukin-3 mutant polypeptide is of the Formula : Asn Cys Xaa Xaa Met He Asp Glu Xaa He Xaa Xaa Leu Lys Xaa 1 5 10 15 Xaa Pro Xaa Pro Xaa Xaa Asp Phe Xaa Asn Leu Asn Xaa Glu Asp 20 25 30 Xaa Xaa He Leu Met Xaa Xaa Asn Leu Arg Xaa Xaa Asn Leu Glu 35 40 45 Ala Phe Xaa Arg Xaa Xaa Lys Xaa Xaa Xaa Asn Ala Ser Ala He 50 55 60 Glu Xaa Xaa Leu Xaa Xaa Leu Xaa Pro Cys Leu Pro Xaa Xaa Thr 65 70 75 Ala Xaa Pro Xaa Arg Xaa Pro He Xaa Xaa Xaa Xaa Gly Asp Trp 80 85 90 Xaa Glu Phe Xaa Xaa Lys Leu Xaa Phe Tyr Leu Xaa Xaa Leu Glu 95 100 105 Xaa Xaa Xaa Xaa Gin Gin [SEQ ID NO : 22 ] 110 wherein Xaa at position 3 is Ser, Gly, Asp, or Gin; Xaa at position 4 is Asn, His, or lie; Xaa at position 9 is He, Ala, Leu, or Gly; Xaa at position 11 is Thr, His, or Gin; Xaa at position 12 is His or Ala; Xaa at position 15 is Gin or Asn; Xaa at position 16 is Pro or Gly; Xaa at position 18 is Leu, Arg, Asn, or Ala; Xaa at position 20 is Leu, Val, Ser, Ala, Arg, Gin, Glu, He, Phe, Thr or Met; Xaa at position 21 is Leu, Ala, Asn, or Pro; Xaa at position 24 is Asn or Ala; Xaa at position 28 is Gly, Asp, Ser, Ala, Asn, He, Leu, Met, Tyr or Arg; Xaa at position 31 is Gin, Val, Met, Leu, Ala, Asn, Glu or Lys; Xaa at position 32 is Asp, Phe, Ser, Ala, Gin, Glu, His, Val or Thr; Xaa at position 36 is Glu, Asn, Ser or Asp; Xaa at position 37 is Asn, Arg, Pro, Thr, or His; Xaa at position 41 is Arg, Leu, or Gly; Xaa at position 42 is Pro, Gly, Ser, Ala, Asn, Val, Leu or Gin; Xaa at position 48 is Asn, Pro, or Thr; Xaa at position 50 is Ala or Asn; Xaa at position 51 is Val or Thr; Xaa at position 53 is Ser or Phe; Xaa at position 54 is Leu or Phe; Xaa at position 55 is Gin, Ala, Glu, or Arg; Xaa at position 62 is Ser, Val, Asn, Pro, or Gly; Xaa at position 63 is He or Leu; Xaa at position 65 is Lys, Asn, Met, Arg, He, or Gly; Xaa at position 66 is Asn, Gly, Glu, or Arg; Xaa at position 68 is Leu, Gin, Trp, Arg, Asp, Asn, Glu, His, Met, Phe, Ser, Thr, Tyr or Val; Xaa at position 73 is Leu or Ser; Xaa at position 74 is Ala or Trp; Xaa at position 77 is Ala or Pro; Xaa at position 79 is Thr, Asp, or Ala; Xaa at position 81 is His, Pro, Arg, Val, Gly, Asn, Ser or Thr; Xaa at position 84 is His, He, Asn, Ala, Thr, Arg, Gin, Glu, Lys, Met, Ser, Tyr, Val or Leu; Xaa at position 85 is He or Leu; Xaa at position 86 is Lys or Arg; Xaa at position 87 is Asp, Pro, Met, Lys, His, Pro, Asn, He, Leu or Tyr; Xaa at position 91 is Asn, Pro, Ser, He or Asp; Xaa at position 94 is Arg, Ala, or Ser; Xaa at position 95 is Arg, Thr, Glu, Leu, or Ser; Xaa at position 98 is Thr or Gin; Xaa at position 102 is Lys, Val, Trp, or lie; Xaa at position 103 is Thr, Ala, His, Phe, Tyr or Ser; Xaa at position 106 is Asn, Pro, Leu, His, Val, or Gin; Xaa at position 107 is Ala, Ser, He, Pro, or Asp; Xaa at position 108 is Gin, Met, Trp, Phe, Pro, His, He, or Tyr; Xaa at position 109 is Ala, Met, Glu, Ser, or Leu; and which can additionally have Met- or Met-Ala- preceding the amino acid in position 1; and wherein from 1 to 3 of the amino acids designated by Xaa are different from the corresponding amino acids of native (l-133)human interleukin-3. 19. The method of claim 20, wherein said human interleukin-3 mutant polypeptide is of the Formula: Xaa at position 17 is Ser, Lys, Asp, Met, Gin, or Arg; Xaa at position 18 is Asn, His, Leu, He, Phe, Arg, or Gin; Xaa at position 19 is Met, Arg, Gly, Ala, or Cys; Xaa at position 20 is He, Cys, Gin, Glu, Arg, Pro, or Ala; Xaa at position 21 is Asp, Phe, Lys, Arg, Ala, Gly, or Val; Xaa at position 22 is Glu, Trp, Pro, Ser, Ala, His, or Gly; Xaa at position 23 is He, Ala, Gly, Trp, Lys, Leu, Ser, or Arg; Xaa at position 24 is He, Gly, Arg, or Ser; Xaa at position 25 is Thr, His, Gly, Gin, Arg, Pro, or Ala; Xaa at position 26 is His, Thr, Phe, Gly, Ala, or Trp; Xaa at position 27 is Leu, Gly, Arg, Thr, Ser, or Ala; Xaa at position 28 is Lys, Leu, Gin, Gly, Pro, Val or Trp; Xaa at position 29 is Gin, Asn, Pro, Arg, or Val; Xaa at position 30 is Pro, His, Thr, Gly, Asp, Gin, Ser, Leu, or Lys; Xaa at position 31 is Pro, Asp, Gly, Arg, Leu, or Gin; Xaa at position 32 is Leu, Arg, Gin, Asn, Gly, Ala, or Glu; Xaa at position 33 is Pro, Leu, Gin, Thr, or Glu; Xaa at position 34 is Leu, Gly, Ser, or Lys; Xaa at position 35 is Leu, Ala, Gly, Asn, Pro, or Gin; Xaa at position 36 is Asp, Leu, or Val; Xaa at position 37 is Phe, Ser, or Pro; Xaa at position 38 is Asn, or Ala; Xaa at position 40 is Leu, Trp, or Arg; Xaa at position 41 is Asn, Cys, Arg, Leu, His, Met, Pro; Xaa at position 42 is Gly, Asp, Ser, Cys, or Ala; Xaa at position 42 is Glu, Asn, Tyr, Leu, Phe, Asp, Ala, Cys, or Ser; Xaa at position 44 is Asp, Ser, Leu, Arg, Lys, Thr, Met, Trp, or Pro; Xaa at position 45 is Gin, Pro, Phe, Val, Met, Leu, Thr, Lys, or Trp; Xaa at position 46 is Asp, Phe, Ser, Thr, Cys, or Gly; Xaa at position 47 is He, Gly, Ser, Arg, Pro, or His; Xaa at position 48 is Leu, Ser, Cys, Arg, His, Phe, or Asn; Xaa at position 49 is Met, Arg, Ala, Gly, Pro, Asn, His, or Asp; Xaa at position 50 is Glu, Leu, Thr, Asp, or Tyr; Xaa at position 51 is Asn, Arg, Met, Pro, Ser, Thr, or His; Xaa at position 52 is Asn, His, Arg, Leu, Gly, Ser, or Thr; Xaa at position 53 is Leu, Thr, Ala, Gly, Glu, Pro, Lys, Ser, or; Xaa at position 54 is Arg, Asp, He, Ser, Val, Thr, Gin, or Leu; Xaa at position 55 is Arg, Thr, Val, Ser, Leu, or Gly; Xaa at position 56 is Pro, Gly, Cys, Ser, Gin, or Lys; Xaa at position 57 is Asn or Gly; Xaa at position 58 is Leu, Ser, Asp, Arg, Gin, Val, or Cys; Xaa at position 59 is Glu Tyr, His, Leu, Pro, or Arg; Xaa at position 60 is Ala, Ser, Tyr, Asn, or Thr; Xaa at position 61 is Phe, Asn, Glu, Pro, Lys, Arg, or Ser; Xaa at position 62 is Asn His, Val, Arg, Pro, Thr, or lie; Xaa at position 63 is Arg, Tyr, Trp, Ser, Pro, or Val; Xaa at position 64 is Ala, Asn, Ser, or Lys; Xaa at position 65 is Val, Thr, Pro, His, Leu, Phe, or Ser; Xaa at position 66 is Lys, He, Val, Asn, Glu, or Ser; Xaa at position 67 is Ser, Ala, Phe, Val, Gly, Asn, He, Pro, or His; Xaa at position 68 is Leu, Val, Trp, Ser, Thr, or His; Xaa at position 69 is Gin, Ala, Pro, Thr, Arg, Trp, Gly, or Leu; Xaa at position 70 is Asn, Leu, Val, Trp, Pro, or Ala; Xaa at position 71 is Ala, Met, Leu, Arg, Glu, Thr, Gin, Trp, or Asn; Xaa at position 72 is Ser, Glu, Met, Ala, His, Asn, Arg, or Asp; Xaa at position 73 is Ala, Glu, Asp, Leu, Ser, Gly, Thr, or Arg; Xaa at position 74 is He, Thr, Pro, Arg, Gly, Ala; Xaa at position 75 is Glu, Lys, Gly, Asp, Pro, Trp, Arg, Ser, or Leu; Xaa at position 76 is Ser, Val, Ala, Asn, Trp, Glu, Pro, Gly, or Asp; Xaa at position 77 is He, Ser, Arg, or Thr; Xaa at position 78 is Leu, Ala, Ser, Glu, Gly, or Arg; Xaa at position 79 is Lys, Thr, Gly, Asn, Met, He, or Asp; Xaa at position 80 is Asn, Trp, Val, Gly, Thr, Leu, or Arg; Xaa at position 81 is Leu, Gin, Gly, Ala, Trp, Arg, or Lys; Xaa at position 82 is Leu, Gin, Lys, Trp, Arg, or Asp; Xaa at position 83 is Pro, Thr, Trp, Arg, or Met; Xaa at position 84 is Cys, Glu, Gly, Arg, Met, or Val; Xaa at position 85 is Leu, Asn, or Gln; Xaa at position 86 is Pro, Cys, Arg, Ala, or Lys; Xaa at position 87 is Leu, Ser, Trp, or Gly; Xaa at position 88 is Ala, Lys, Arg, Val, or Trp; Xaa at position 89 is Thr, Asp, Cys, Leu, Val, Glu, His, or Asn; Xaa at position 90 is Ala, Ser, Asp, He, or Met; Xaa at position 91 is Ala, Ser, Thr, Phe, Leu, Asp, or His; Xaa at position 92 is Pro, Phe, Arg, Ser, Lys, His, or Leu; Xaa at position 93 is Thr, Asp, Ser, Asn, Pro, Ala, Leu, or Arg; Xaa at position 94 is Arg, He, Ser, Glu, Leu, Val, or Pro; Xaa at position 95 is His, Gin, Pro, Val, Leu, Thr or Tyr; Xaa at position 96 is Pro, Lys, Tyr, Gly, He, or Thr; Xaa at position 97 is He, Lys, Ala, or Asn; Xaa at position 98 is His, He, Asn, Leu, Asp, Ala, Thr, or Pro; Xaa at position 99 is He, Arg, Asp, Pro, Gin, Gly, Phe, or His; Xaa at position 100 is Lys, Tyr, Leu, His, He, Ser, Gin, or Pro; Xaa at position 101 is Asp, Pro, Met, Lys, His, Thr, Val, Tyr, or Gin; Xaa at position 102 is Gly, Leu, Glu, Lys, Ser, Tyr, or Pro; Xaa at position 103 is Asp, or Ser; Xaa at position 104 is Trp, Val, Cys, Tyr, Thr, Met, Pro, Leu, Gin, Lys, Ala, Phe, or Gly; Xaa at position 105 is Asn, Pro, Ala, Phe, Ser, Trp, Gin, Tyr, Leu, Lys, He, or His; Xaa at position 106 is Glu, Ser, Ala, Lys, Thr, He, Gly, or Pro; Xaa at position 108 is Arg, Asp, Leu, Thr, He, or Pro; Xaa at position 109 is Arg, Thr, Pro, Glu, Tyr, Leu, Ser, or Gly. 20, The method of claim 19 wherein said human interleukin-3 mutant polypeptide is of the Formula: 1 5 10 (Met) m - la Pro Met Thr Gin Thr Thr Ser Leu Lys Thr 15 20 Ser Trp Val Asn Cys Ser Xaa Xaa Xaa Asp Glu lie lie 25 30 35 Xaa His Leu Lys Xaa Pro Pro Xaa Pro Xaa Leu Asp Xaa 40 45 50 Xaa Asn Leu Asn Xaa Glu Asp Xaa Asp lie Leu Xaa Glu 55 60 Xaa Asn Leu Arg Xaa Xaa Asn Leu Xaa Xaa Phe Xaa Xaa 65 70 75 Ala Xaa Lys Xaa Leu Xaa Asn Ala Ser Xaa lie Glu Xaa 80 85 lie Leu Xaa Asn Leu Xaa Pro Cys Xaa Pro Xaa Xaa Thr 90 95 100 Ala Xaa Pro Xaa Arg Xaa Pro lie Xaa lie Xaa Xaa Gly 105 110 115 Asp Trp Xaa Glu Phe Arg Xaa Lys Leu Xaa Phe Tyr Leu 120 125 Xaa Xaa Leu Glu Xaa Ala Gin Xaa Gin Gin Thr Thr Leu 130 Ser Leu Ala He Phe [SEQ ID NO:129] wherein m is 0 or 1; Xaa at position 18 is Asn or He; Xaa at position 19 is Met, Ala or He; Xaa at position 20 is He, Pro or He; Xaa at position 23 is He, Ala or Leu; Xaa at position 25 is Thr or His; Xaa at position 29 is Gin, Arg, Val or lie; Xaa at position 32 is Leu, Ala, Asn or Arg; Xaa at position 34 is Leu or Ser; Xaa at position 37 is Phe, Pro, or Ser; Xaa at position 38 is Asn or Ala; Xaa at position 42 is Gly, Ala, Ser, Asp or Asn; Xaa at position 45 is Gin, Val, or Met; Xaa at position 46 is Asp or Ser; Xaa at position 49 is Met, He, Leu or Asp; Xaa at position 50 is Glu or Asp; Xaa at position 51 is Asn Arg or Ser; Xaa at position 55 is Arg, Leu, or Thr; Xaa at position 56 is Pro or Ser; Xaa at position 59 is Glu or Leu; Xaa at position 60 is Ala or Ser; Xaa at position 62 is Asn, Val or Pro; Xaa at position 63 is Arg or His; Xaa at position 65 is Val or Ser; Xaa at position 67 is Ser, Asn, His or Gin; Xaa at position 69 is Gin or Glu; Xaa at position 73 is Ala or Gly; Xaa at position 76 is Ser, Ala or Pro; Xaa at position 79 is Lys, Arg or Ser; Xaa at position 82 is Leu, Glu, Val or Trp; Xaa at position 85 is Leu or Val; Xaa at position 87 is Leu, Ser, Tyr; Xaa at position 88 is Ala or Trp; Xaa at position 91 is Ala or Pro; Xaa at position 93 is Pro or Ser; Xaa at position 95 is His or Thr; Xaa at position 98 is His, He, or Thr; Xaa at position 100 is Lys or Arg; Xaa at position 101 is Asp, Ala or Met; Xaa at position 105 is Asn or Glu; Xaa at position 109 is Arg, Glu or Leu; Xaa at position 112 is Thr or Gin; Xaa at position 116 is Lys, Val, Trp or Ser; Xaa at position 117 is Thr or Ser; Xaa at position 120 is Asn, Gin, or His; Xaa at position 123 is Ala or Glu; with the proviso that from one to three of the amino acids designated by Xaa are different from the corresponding amino acids of native human interleukin-3. 21. The method of claim 22 wherein said human interleukin-3 mutant polypeptide is of the Formula: 1 5 10 (Met m -Ala n )p-Asn Cys Ser Xaa Xaa Xaa Asp Glu Xaa lie 15 20 Xaa His Leu Lys Xaa Pro Pro Xaa Pro Xaa Leu Asp Xaa 25 30 35 Xaa Asn Leu Asn Xaa Glu Asp Xaa Xaa He Leu Xaa Glu 40 45 Xaa Asn Leu Arg Xaa Xaa Asn Leu Xaa Xaa Phe Xaa Xaa 50 55 60 Ala Xaa Lys Xaa Leu Xaa Asn Ala Ser Xaa He Glu Xaa 65 70 75 He Leu Xaa Asn Xaa Xaa Pro Cys Xaa Pro Xaa Ala Thr 80 85 Ala Xaa Pro Xaa Arg Xaa Pro He Xaa He Xaa Xaa Gly 90 95 100 Asp Trp Xaa Glu Phe Arg Xaa Lys Leu Xaa Phe Tyr Leu 105 110 Xaa Xaa Leu Glu Xaa Ala Gin Xaa Gin Gin [SEQ ID NO:130] wherein m is 0 or 1; n is 0 or 1; p is 0 or 1; Xaa at position 4 is Asn or He; Xaa at position 5 is Met, Ala or He: Xaa at position 6 is He, Pro or Leu; Xaa at position 9 is He, Ala or Leu; Xaa at position 11 is Thr or His; Xaa at position 15 is Gin, Arg, Val or He; Xaa at position 18 is Leu, Ala, Asn or Arg; Xaa at position 20 is Leu or Ser; Xaa at position 23 is Phe, Pro, or Ser; Xaa at position 24 is Asn or Ala; Xaa at position 28 is Gly, Ala, Ser, Asp or Asn; Xaa at position 31 is Gin, Val, or Met; Xaa at position 32 is Asp or Ser; Xaa at position 35 is Met, He or Asp; Xaa at position 36 is Glu or Asp; Xaa at position 37 is Asn, Arg or Ser; Xaa at position 41 is Arg, Leu, or Thr; Xaa at position 42 is Pro or Ser; Xaa at position 45 is Glu or Leu; Xaa at position 46 is Ala or Ser; Xaa at position 48 is Asn, Val or Pro; Xaa at position 49 is Arg or His; Xaa at position 51 is Val or Ser; Xaa at position 53 is Ser, Asn, His or Gin; Xaa at position 55 is Gin or Glu; Xaa at position 59 is Ala or Gly; . Xaa at position 62 is Ser, Ala or Pro; Xaa at position 65 is Lys, Arg or Ser; Xaa at position 67 is Leu, Glu, or Val; Xaa at position 68 is Leu, Glu, Val or Trp; Xaa at position 71 is Leu or Val; Xaa at position 73 is Leu, Ser or Tyr; Xaa at position 74 is Ala or Trp; Xaa at position 77 is Ala or Pro; Xaa at position 79 is Pro or Ser; Xaa at position 81 is His or Thr; Xaa at position 84 is His, He, or Thr; Xaa at position 86 is Lys or Arg; Xaa at position 87 is Asp, Ala or Met; Xaa at position 91 is Asn or Glu; Xaa at position 95 is Arg, Glu Leu; Xaa at position 98 Thr or Gin; Xaa at position 102 is Lys, Val, Trp or Ser; Xaa at position 103 is Thr or Ser; Xaa at position 106 is Asn, Gin, or His; Xaa at position 109 is Ala or Glu; with the proviso that from one to three of the amino acids designated by Xaa are different from the corresponding amino acids of native (15-125)human interleukin-3. 22. The method of claim 12, 13,or 15 wherein said CSF is G-CSF or GM-CSF. 23. The method as recited as recited in claim 22 wherein said G-CSF is Administered simultaneously or after said human interleukin-3 mutant polypeptide.

Inventors: ABRAMS MARK ALLEN, BAUER CHRISTOPHER S, BRADFORD-GOLDBERG SARAH RUTH, CAPARON MARIE HELENA, EASTON ALAN MICHAEL, KLEIN BARBARA KURE, MCKEARN JOHN PATRICK, OLINS PETER O, PAIK KUMNAN, THOMAS JOHN WARREN, ABRAMS, MARK, ALLEN, BAUER, CHRISTOPHER, S., BRADFORD-GOLDBERG, SARAH, RUTH, CAPARON, MARIE, HELENA, EASTON, ALAN, MICHAEL, KLEIN, BARBARA, KURE, MCKEARN, JOHN, PATRICK, OLINS, PETER, O., PAIK, KUMNAN, THOMAS, JOHN, WARREN
Applicants: ABRAMS MARK ALLEN, BAUER CHRISTOPHER S, BRADFORD GOLDBERG SARAH RUTH, CAPARON MARIE HELENA, EASTON ALAN MICHAEL, KLEIN BARBARA KURE, MCKEARN JOHN PATRICK, OLINS PETER O, PAIK KUMNAN, SEARLE & CO, THOMAS JOHN WARREN, ABRAMS, MARK, ALLEN, BAUER, CHRISTOPHER, S., BRADFORD-GOLDBERG, SARAH, RUTH, CAPARON, MARIE, HELENA, EASTON, ALAN, MICHAEL, G.D. SEARLE & CO., KLEIN, BARBARA, KURE, MCKEARN, JOHN, PATRICK, OLINS, PETER, O., PAIK, KUMNAN, THOMAS, JOHN, WARREN
Application year: 1995
Main classification: A61K38
IPC codes: A61K38, A61P7, C07K14, C12N15, C12P21