HUMAN ICE HOMOLOG

Abstract: The present invention provides nucleotide and amino acid sequences that identify and encode a new human interleukin-1 converting enzyme homolog (ICEY). The present invention also provides for antisense molecules to the nucleotide sequences which encode ICEY, expression vectors for the production of purified ICEY, antibodies capable of binding specifically to ICEY, hybridization probes or oligonucleotides for the detection of ICEY-encoding nucleotide sequences, genetically engineered host cells for the expression of ICEY, diagnostic tests for activation of monocyte/macrophages based on ICEY-encoding nucleic acid molecules, and use of the protein to produce antibodies capable of binding specifically to the protein and use of the protein to screen for inhibitors.

Description: HUMAN ICE HOMOLOG TECHNICAL FIELD The present invention is in the field of molecular biology; more particularly, the present invention describes the nucleic acid and amino acid sequences of a novel interleukin-1 converting enzyme homolog derived from activated THP-1 cells. RELATED AND CO-PENDING APPLICATIONS This application is a continuation-in-part of United States Application Serial Number 08/443,865, filed May 31, 1995, which is incorporated herein in its entirety. BACKGROUND ART To understand the interleukin 1 converting enzyme (ICE) , it is helpful to first examine the role of interleukin-1 (IL-1), its enzymatic substrate. IL-1 facilitates host natural immunity, predominantly those aspects related to the initiation of inflammatory reactions that protect the body against bacterial infection. (Ayala et al . (1994) J. Immunol. 53: 2592-2599). At low concentrations in the bloodstream, IL-1 mediates local inflammation by inducing the synthesis of other cytokines, such as IL-6 and IL-8, and the synthesis of proteins that mediate leukocyte adhesion, and prostaglandin production. (Abbas et al . (1994) Cellular and Molecular Immunology, .B. Saunders Company) . At intermediate concentrations, IL-1 enters the bloodstream and may induce fever, the synthesis of acute plasma proteins by the liver, and metabolic wasting (cachexia) (Abbas, supra) . At even higher concentrations, IL-1 has been implicated in tissue destruction observed in numerous inflammation-related diseases, including rheumatoid arthritis, septic shock, inflammatory bowel disease and insulin-dependent diabetes mellitus. (Li et al . (1995) Cell 80:401-411). IL-1 activity results from the expression and release of two gene products, IL-iα and IL-lβ, predominantly from activated monocytes. (Howard et al. (1991) J. Immunology 147:2964-2969). Both gene products are initially synthesized as inactive precursors of about 31 kDa in monocytes. Pre-IL-lβ is cleaved to an active 17 kDa form by the IL-lβ-converting enzyme (ICE) before release from activated monocytes. Pre-IL-lα is likely cleaved to an active 17 kDa form by a calpain-like IL-iα-converting enzyme prior to release. (Carruth et al . (1991) J. Biol. Chem. 266:12162-12167). Additionally, ICE has been implicated in IL-lα 's release from activated monocytes but the mechanism is not understood (Li, supra) . The IL-lβ gene product is the predominant form of IL-1 that is present at high concentrations in the bloodstream during inflammatory diseases, such as rheumatoid arthritis, septic shock, inflammatory bowel disease, and insulin-dependent diabetes mellitus (Li, supra) . Since the cleavage of pre- IL-lβ by ICE is coupled to IL-lβ release and to increased IL-1 activity in the bloodstream, ICE activity may be higher in these pathological conditions. The importance of regulating ICE activity to modulate the IL-lβ concentration to affect the host immune response has recently been confirmed. The crmA gene product of cowpox virus prevents the proteolytic activation of IL-lβ and inhibits the host inflammatory response. Cowpox virus containing a deleted crmA gene is unable to suppress the inflammatory response, resulting in a reduction of virus-infected cells and less damage to the host. (Miura et al . (1993) Cell 75: 653-660) . ICE is a novel cysteine protease that is known specifically to cleave inactive IL-lβ precursor to its active form. (Ayala, supra) . This protease recognizes the sequence Asp-X, where X is preferably a small hydrophobic amino acid residue, and cleaves the bond between Asp and X. However, many Asp-X bonds are not recognized by ICE suggesting that flanking sequences or other criteria such as accessibility are also required for recognition and cleavage. In the case of IL-lβ, ICE cleaves the precursor to form active IL- lβ at two sequence-specific bonds, the bond between residues Asp-27 and Gly-28 and the bond between residues Asp-116 and Ala-117. ICE itself is synthesized and maintained in cells as an inactive 45 kDa precursor which is processed into the active ICE consisting of 20- and 10-kDa subunits, p20 and plO. (Ayala, supra). Both subunits are derived from the 45 kDa precursor which is cleaved into four different fragments, a 13 kDa precursor domain, the p20 sub-unit, a 2 kDa spacer, and the plO sub-unit. Since all these polypeptide fragments are flanked by Asp-X residues in the intact 45 kDa precursor it is possible that the ICE precursor is activated autocatalytically. (Ayala, supra) . The three dimensional structure of ICE has been determined from crystallographic studies. (Walker et al . (1994) Cell 78:343-352) . First, it is apparent that the active form of ICE is a homodimer of catalytic domains, each of which consists of p20 and plO subunits. Second, although the active site cysteine residue is located on p20, both p20 and plO are essential for activity. Subunit structures p20 and plO are intertwined so as to create a unique 6-stranded beta-sheet core flanked on either side by alpha helices. The first 4 beta strands are contributed by p20, while the remaining 2 beta strands are contributed by plO. ICE genes from various sources have been sequenced and possess an overall 29% amino acid homology to the Caenorhabditis elegans gene ced-3 product a gene with a possible role in apoptosis (Yuan et al . (1993) Cell 75: 641-652) . Additionally, the ICE gene contains a sequence region, encoding residues 166 to 287, which shares a 43% homology with ced-3. It is not known whether ced-3 acts as a cysteine protease but it contains the purported catalytic residues that are located at the ICE active site (Cys 285 and His 237 ) . The amino acid pentapeptide Glu-Ala-Cys-Arg-Gly (QACRG) , containing the active site cysteine, is the longest peptide conserved among ICE, from mice and humans, and CED-3, from three different nematodes. Additionally, ced-3 contains the same four residues whose side chains are implicated in binding the aspartate carboxylate group of the substrate at the catalytic site (Arg- 179, Gln-283, Ser 347, and Arg-341) (Yuan, supra) . Inhibition with the ICE-specific inhibitor crnA blocks TNF- and FAS- induced apoptosis. Therefore, ICE or a homolog is believed to be involved in TNF- and FAS-induced apoptosis. Additionally, ICE possesses a degree of homology to the mammalian gene Nedd-2/Ich-l, a gene product with a possible role in embryogenesis which is expressed during embryonic brain development and is down-regulated in the adult brain. (Yuan, supra) . Nedd-2, ced-3, and ICE gene products are about 27% homologous. The carboxy termini of CED-3 and plO possess the highest degree of homology to Nedd-2. The Nedd-2 gene product does not contain the highly conserved cysteine nor the highly conserved QACRG pentapeptide found in ICE and is probably not a cysteine protease. To confirm ICE's role in inflammation-related diseases by controlling the levels of active IL-lβ, Li, supra created ICE-deficient knockout mice. These genetically-engineered mice were normal physiologically but lacked the ability to process precursor IL-lβ to its active form when monocytes were activated with microbial products, such as lipopolysaccharide (LPS) . Additionally, the production of IL-iα was decreased, and the level of other cytokines, tumor necrosis factor (TNF) and IL-6, involved in inflammatory responses to microbial products was somewhat reduced. These mice were resistant to the lethal effects of septic shock when exposed to LPS (Li, supra) . Therefore, inhibiting ICE activity to reduce the concentration of IL-lβ in the bloodstream may be a method of treating inflammation-related diseases. ICE may be used to help identify patients who are susceptible to these diseases. Since ICE shares sequence homology to ced-3 and overexpression of ICE appears to induce apoptosis, the ICE-deficient mice studies were important because the mice seemed normal in terms of their development. If ICE played a strong role in apoptosis during development, the ICE-deficient mice should have had gross abnormalities in brain, gut, lymphoid and brain tissues (Li, supra) . However, ICE may perform functions other than IL-lβ precursor cleavage. ICE mRNA has been detected in a greater variety of tissues than IL- lβ mRNA has (Miura, supra) . ICE has attracted interest as a target for novel anti-inflammatory drugs, because the cytokine which it activates, IL-lβ, is proinflammatory and has been implicated in the pathophysiology of various diseases, including rheumatoid arthritis, septic shock, inflammatory bowel disease and insulin- dependent diabetes mellitus (Dinarello and Wolff (1993) N Engl J Med 328:106- 13) . The provision of a new ICE gene and polypeptide will further drug research in screening for and designing more effective and more specific inhibitors to this pro-inflammatory substance. Not surprisingly, this ICE homolog was found in a library of activated monocytic cells, namely, phorbol- and endotoxin-treated THP-1 cells. THP-1 Cells THP-1 is a human leukemic cell line with distinct monocytic characteristics derived from the blood of a 1-year-old boy with acute monocytic leukemia (Tsuchiya S et al (1980) Int J Cancer 26:171-176). The monocytic nature of THP-1 was established using the following cytological and cytochemical criteria: 1) a-naphthyl butyrate esterase activity which could be inhibited by NaF (sodium fluoride) , 2) production of lysozyme, 3) phagocytosis (the engulfing of extracellular materials) of latex particles and sensitized sheep red blood cells, and 4) ability of mitomycin C-treated THP-1 cells to activate T-lymphocytes following concanavalin A treatment. Morphologically, the cytoplasm contained small azurophilic granules, the nucleus was indented and irregularly shaped with deep folds, and the cell membrane had Fc and C3b receptors which probably function in phagocytosis. Monocytes develop from monoblasts through promonocytes in the bone marrow and in their mature form have a half-life of approximately three days. Roughly 75% of the circulating monocyte pool is found along the walls of blood vessels although these cells randomly migrate into tissues and become antigen-presenting or phagocytic. Antigen-presenting monocytes include interdigitating reticular and follicular dendritic cells of the lymph nodes and skin. Phagocytic monocytes are prominent as Kupffer cells of the liver and in the lung alveoli and bone marrow. Whereas precursor monocytes are rich in azurophilic, peroxidase- containing cytoplasmic granules, macrophages have more numerous cell surface receptors by which they monitor their environment. These include receptors for immunoglobulin, complement, growth factors, lipoproteins, peptides and polysaccharides. Binding of ligands to these receptors triggers macrophage proliferation, chemotaxis, secretion and phagocytosis. Many human myeloid and myelomonocytic cell lines retain some ability to differentiate into more mature phenotypes in response to various internal stimuli including growth factors, lymphokines, cytokines, vitamin D derivatives, and tumor promoters and external agents such as trauma, smoking, UV irradiation, asbestos exposure, and steroids. THP-1 cells treated with the tumor promoter 12-0-tetradecanoyl-phorbol-13 acetate (TPA) are induced to stop proliferating and differentiate into macrophage-like cells which mimic native onocyte-derived macrophages both morphologically and physiologically. These monocyte/macrophage-like cells exhibit changes in gene expression such as the coinduction of C-fos and c-jun and the down-regulation of c-myb (Auwerx J (1991) Experientia 47:22-31), increase in density of the complement C3b receptor, and decrease in both FcR and the adhesion molecule, CD4. In addition, THP-1 cells produce lipoprotein lipase and apolipoprotein E associated with atherosclerotic lesions, secrete several proinflammatory cytokines, including IL-lβ and TNF (Cochran FR and Finch-Arietta MB (1989) Agents and Actions 27:271-273), and may elaborate powerful oxidants and tissue destroying proteases, such as the IL-1 converting enzyme. DISCLOSURE OF THE INVENTION The subject invention provides a unique nucleotide sequence which encodes a novel human ICE homolog. The new gene, also known as icey, which was identified within Incyte Clone 14775, encodes ICEY polypeptide and represents a new human cysteine protease. The invention also comprises diagnostic tests for physiologic or pathologic activity of activated monocytes or macrophages which include the steps of testing a sample or an extract thereof with ICE homolog-encoding cDNA, fragments or oligomers thereof. Further aspects of the invention include the antisense of icey; cloning or expression vectors containing icey; host cells or organisms transformed with expression vectors containing icey; a method for the production and recovery of purified ICEY polypeptide from host cells; purified ICEY polypeptide; antibodies and inhibitors to ICEY, and pharmacological compounds using ICEY antibodies. BRIEF DESCRIPTION OF DRAWINGS Figures 1A and IB display the nucleotide sequence for ice homolog and the predicted amino acid sequence of ICE homolog (SEQ ID NO:5 and SEQ ID NO:6, respectively) . Figures 2A and 2B show the amino acid alignment of the novel ICE homolog with the human ICE (GenBank locus HSU13697; GI number 717040) . Alignments shown were produced using the multisequence alignment program of DNASTAR software (DNASTAR Inc, Madison Wl) . Figure 3 displays an analysis of ICE homolog alpha regions (A) , beta regions (B) , turn regions (T) , coil regions (C) , hydrophilicity plot (H) , alpha amphipathic regions (AA) , beta amphipathic regions (BA) , antigenic index (Al) and surface probability plot (S) based on the predicted acid amino sequence and composition. Figure 4 displays the alignment of the partial cDNA sequences with the complete icey gene. MODES FOR CARRYING OUT THE INVENTION Definitions As used herein, the term "ICE homolog" or "ICEY", refers to the polypeptide disclosed in SEQ ID NO:6, or an active fragment thereof, which is encoded by an mRNA transcribed from the ice homolog cDNA of SEQ ID NO:5. ICEY may be naturally occurring or chemically synthesized. As used herein, the lower case "icey" refers to a nucleic acid sequence while an upper case "ICEY" refers to a protein, peptide or amino acid sequence. As used herein the term "active" refers to those forms of ICEY which retain the biologic and/or immunologic activities of naturally occurring ICEY. As used herein the term "naturally occurring ICEY" refers to ICEY produced by human cells that have not been genetically engineered and specifically contemplates various ICEY forms arising from post-translational modifications of the polypeptide including but not limited to acetylation, carboxylation, glycosylation, phosphorylation, lipidation and acylation. As used herein the term "derivative" refers to polypeptides derived from naturally occurring ICEY by chemical modifications such as ubiquitination, labeling (e.g., with radionuclides, various enzymes, etc.), pegylation (derivatization with polyethylene glycol) or by insertion or substitution by chemical synthesis of amino acid such as ornithine, which do not normally occur in human proteins. As used herein the term "variant" or "recombinant variant" or "mutant" refers to any polypeptide differing from naturally occurring ICEY by amino acid insertions, deletions, and substitutions, created using recombinant DNA techniques. Guidance in determining which amino acid residues may be replaced, added or deleted without abolishing activities of interest, such as enzymatic activity, may be found by comparing the sequence of the particular ICEY with that of homologous molecules and minimizing the number of amino acid sequence changes made in regions of high homology or regions of known activity. Preferably, amino acid "substitutions" are the result of replacing one amino acid with another amino acid having similar structural and/or chemical properties, such as the replacement of a leucine with an isoleucine or valine, an aspartate with a glutamate, or a threonine with a serine, i.e., conservative amino acid replacements. "Insertions" or "deletions" are typically in the range of about 1 to 5 amino acids. The variation allowed may be experimentally determined by systematically making insertions, deletions, or substitutions of amino acid in ICEY using recombinant DNA techniques and assaying the resulting recombinant variants for activity. Where desired, nucleic acid encoding ICEY or an ICEY variant can be genetically engineered to contain a "signal or leader sequence" that can direct the polypeptide through the membrane of a cell. As will be understood by one of skill in the art, such a sequence may be naturally occurring on the polypeptides of the present invention or provided from heterologous protein sources by recombinant DNA techniques. As used herein, an ICEY "fragment," "portion," or "segment" refers to a stretch of amino acid residues which has sufficient length to display biologic and/or immunogenic activity and in preferred embodiments will contain at least about 5 amino acids, at least about 7 amino acids, at least about 8 to 13 amino acids, and, in additional embodiments, about 17 or more amino acids. As used herein, an "oligonucleotide" or polynucleotide "fragment", "portion, " or "segment" refers to any stretch of nucleic acids encoding ICEY which is of sufficient length to use as a primer in polymerase chain reaction (PCR) or various hybridization procedures known to those of skill in the art, for the purpose of identifying or amplifying identical or related nucleic acids. The present invention includes purified ICEY polypeptides from natural or recombinant sources, vectors and host cells transformed with recombinant nucleic acid molecules encoding ICEY. Various methods for the isolation of the ICEY polypeptides may be accomplished by procedures well known in the art. For example, such polypeptides may be purified by immunoaffinity chromatography by employing the antibodies provided by the present invention. Various other methods of protein purification well known in the art include those described in Deutscher M (1990) Methods in Enzymology, Vol 182, Academic Press, San Diego; and Scopes R (1982) Protein Purification: Principles and Practice. Springer-Verlag, New York City, both incorporated herein by reference. As used herein the term "recombinant" refers to a polynucleotide which encodes ICEY and is prepared using recombinant DNA techniques. The polynucleotide which encodes ICEY may also include allelic or recombinant variants and mutants thereof. As used herein the term "probe" or "nucleic acid probe" or "oligonucleotide probe" refers to a portion, fragment, or segment of icey that is capable of being hybridized to a desired target nucleotide sequence. A probe can be used to detect, amplify or quantify cDNAs or endogenous nucleic acid encoding ICEY by employing conventional techniques in molecular biology. A probe may be of variable length, preferably from about 10 nucleotides up to several hundred nucleotides. As will be understood by those of skill in the art, hybridization conditions and probe design will vary depending upon the intended use. For example, a probe intended for use in PCR will generally be from about 15 to 30 nucleotides in length, and may include up to 60 nucleotides, and may be part of a pool of degenerate probes, i.e., oligonucleotides which tolerate nucleotide mismatch but accommodate binding to an unknown sequence; whereas a probe for use in Southern or northern hybridizations may be a single, specific nucleotide sequence that is several hundred nucleotides in length. Accordingly, a preferred probe for the specific detection of icey will comprise a polynucleotide or oligonucleotide fragment from a non-conserved nucleotide region of SEQ ID NO:5. As used herein the term "non-conserved nucleotide region" refers to a nucleotide region that is unique to SEQ ID NO:5 and does not comprise a region that is conserved in the family of ICE genes. Probes may be single-stranded or double-stranded and may have specificity in solution, cell, tissue or membrane-based hybridizations including in situ and ELISA-like technologies. The present invention encompasses oligonucleotides, fragments or portions of the polynucleotides disclosed herein, or their complementary strands used as probes. Nucleic acid probes may comprise portions of the sequence having fewer nucleotides than about 6 kb and usually fewer than about 1 kb. The oligonucletides and nucleic acid probes of the present invention may be used to determine whether nucleic acid encoding ICEY is present in a cell or tissue or to isolate identical or similar nucleic acid sequences from chromosomal DNA as described by Walsh PS et al (1992 PCR Methods Appl 1:241-250) . Nucleic acid probes of the present invention may be derived from naturally occurring or recombinant single- or double-stranded nucleic acids or be chemically synthesized. They may be labeled by nick translation, Klenow fill-in reaction, PCR or other methods well known in the art. Probes of the present invention, their preparation and/or labeling are elaborated in Sambrook J et al (1989) Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory, NY; or Ausubel FM et al (1989) Current Protocols in Molecular Biology, John Wiley & Sons, NYC, both incorporated herein by reference. Alternatively, recombinant variants encoding the polypeptides of the present invention or related polypeptides may be synthesized or identified through hybridization techniques known to those of skill in the art by making use of the "redundancy" in the genetic code. Various codon substitutions, such as the silent changes which produce various restriction sites, may be introduced to optimize cloning into a plasmid or viral vector or expression in a particular prokaryotic or eukaryotic system. Mutations may also be introduced to modify the properties of the polypeptide, to change ligand-binding affinities, interchain affinities, or polypeptide degradation or turnover rate. One example involves inserting a stop codon into the nucleotide sequence to limit the size of ICEY so as to provide a binding, non-activating ligand of smaller molecular mass which would serve to block the activity of the natural ICEY. "Activated monocytes" as used herein refers to the activated, mature monocytes or macrophages found in immunologically active tissues. "Monocyte/macrophage disorders" include but are not limited to inflammatory bowel disease, insulin-dependent diabetes mellitus, rheumatoid arthritis, and sepsis. "Animal" as used herein may be defined to include human, domestic or agricultural (cats, dogs, cows, sheep, etc) or test species (mouse, rat, rabbit, etc) . The present invention includes purified ICEY polypeptides from natural or recombinant sources, cells transformed with recombinant nucleic acid molecules encoding ICEY. Various methods for the isolation of the ICEY polypeptides may be accomplished by procedures well known in the art. For example, such polypeptides may be purified by immunoaffinity chromatography by employing the antibodies provided by the present invention. Various other methods of protein purification well known in the art include those described in Deutscher M (1990) Methods in Enzymology, Vol 182, Academic Press, San Diego CA; and Scopes R (1982) Protein Purification: Principles and Practice. Springer-Verlag, New York City, both incorporated herein by reference. "ICE inhibitors", or ICE-like molecules that bind IL-1 but do not activate it, can be synthesized recombinantly by substituting the cysteine for other natural (such as alanine) or synthetic amino acids in the active pentapeptide site. Alternately, the cysteine can be chemically modified by methods routine in the art, so as to inhibit activation. ICE homologs with modified specificity can be readily synthesized by substituting the non-cysteine residues of the conserved pentapeptide, GLU ALA CYS ARG GLY. The preparation of such recombinant mutants are well known in the art. Substitution of the four non-cysteine amino acids of the pentapeptide with other natural and synthetic amino acids can be readily performed by those of skill in the art. The activity of ICE mutants can be tested by methods known to those of skill in the art. The present invention provides a nucleotide sequence found within Incyte clone 14775 uniquely identifying a new, human ICE homolog (ICEY) of the cysteine protease family which was initially found expressed in THP-1 cells treated with phorbol ester. Because ICEY is expressed in activated monocytes, the nucleic acids (icey) , polypeptides (ICEY) and antibodies to ICEY are useful in diagnostic assays based on identification of ICEY associated with inflammation or inflammatory disease processes. ICEY was also found expressed in cDNA libraries made from macrophages; ovarian tumor; colon; fetal placenta; breast; prostate tumor; synovium from a rheumatoid knee, a osteoarthritic knee and a rheumatoid wrist; lymphocytes; lymphocytes from a 24 hour mixed lymphocyte reaction; spleen; pancreas; spinal cord; cervix; lung; peripheral blood granulocytes treated with fMLP; ganglioneuroma; fetal liver/spleen; neonatal placenta; and eosinophils from an individual having hyper eosinophilia. Excessive expression of ICEY may lead to tissue damage or destruction. Therefore, a diagnostic test for ICEY can accelerate diagnosis and proper treatment of numerous inflammatory disorders including activated monocyte disorders such as inflammatory bowel disease, insulin-dependent diabetes mellitus, rheumatoid arthritis, septic shock and similar pathologic problems. The nucleotide sequences encoding ICEY (or their complement) have numerous applications in techniques known to those skilled in the art of molecular biology. These techniques include use as hybridization probes, use in the construction of oligomers for PCR, use for chromosome and gene mapping, use in the recombinant production of ICEY, and use in generation of anti-sense DNA or RNA, their chemical analogs and the like. Uses of nucleotides encoding ICEY disclosed herein are exemplary of known techniques and are not intended to limit their use in any technique known to a person of ordinary skill in the art. Furthermore, the nucleotide sequences disclosed herein may be used in molecular biology techniques that have not yet been developed, provided the new techniques rely on properties of nucleotide sequences that are currently known, e.g., the triplet genetic code and specific base pair interactions. It will be appreciated by those skilled in the art that as a result of the degeneracy of the genetic code, a multitude of ICEY-encoding nucleotide sequences, some bearing minimal homology to the nucleotide sequence of any known and naturally occurring gene may be produced. The invention has specifically contemplated each and every possible variation of nucleotide sequence that could be made by selecting combinations based on possible codon choices. These combinations are made in accordance with the standard triplet genetic code as applied to the nucleotide sequence of naturally occurring icey, and all such variations are to be considered as being specifically disclosed. Although the nucleotide sequences which encode ICEY and/or its variants are preferably capable of hybridizing to the nucleotide sequence of the naturally occurring icey under stringent conditions, it may be advantageous to produce nucleotide sequences encoding ICEY or its derivatives possessing a substantially different codon usage. Codons can be selected to increase the rate at which expression of the peptide occurs in a particular prokaryotic or eukaryotic expression host in accordance with the frequency with which particular codons are utilized by the host. Other reasons for substantially altering the nucleotide sequence encoding ICEY and/or its derivatives without ' altering the encoded amino acid sequence include the production of RNA transcripts having more desirable properties, such as a greater half-life, than transcripts produced from the naturally occurring sequence. Nucleotide sequences encoding ICEY may be joined to a variety of other nucleotide sequences by means of well established recombinant DNA techniques (cf Sambrook J et al., supra). Useful nucleotide sequences for joining to icey include an assortment of cloning vectors, e.g., plasmids, cosmids, lambda phage derivatives, phagemids, and the like, that are well known in the art. Vectors of interest include expression vectors, replication vectors, probe generation vectors, sequencing vectors, and the like. In general, vectors of interest may contain an origin of replication functional in at least one organism, convenient restriction endonuclease sensitive sites, and selectable markers for the host cell. Another aspect of the subject invention is to provide for icey-specific nucleic acid hybridization probes capable of hybridizing with naturally occurring nucleotide sequences encoding ICEY. Such probes may also be used for the detection of similar ICEY encoding sequences and should preferably contain at least 50% of the nucleotides from the conserved region or active site. The hybridization probes of the subject invention may be derived from the nucleotide sequences of the Figures 1A and IB or from genomic sequences including promoters, enhancer elements and/or possible introns of the respective naturally occurring iceys. Hybridization probes may be labeled by a variety of reporter groups, including radionuclides such as 32 P or 35 S, or enzymatic labels such as alkaline phosphatase coupled to the probe via avidin/biotin coupling systems, and the like. PCR as described U.S. Patent Nos. 4,683,195; 4,800,195; and 4,965,188 provides additional uses for oligonucleotides based upon the nucleotide sequence which encodes ICEY. Such probes used in PCR may be of recombinant origin, may be chemically synthesized, or a mixture of both and comprise a discrete nucleotide sequence for diagnostic use or a degenerate pool of possible sequences for identification of closely related genomic sequences. Other means of producing specific hybridization probes for icey DNAs include the cloning of nucleic acid sequences encoding ICEY or ICEY derivatives into vectors for the production of mRNA probes. Such vectors are known in the art and are commercially available and may be used to synthesize RNA probes in vitro by means of the addition of the appropriate RNA polymerase as T7 or SP6 RNA polymerase and the appropriate radioactively labeled nucleotides. It is now possible to produce a DNA sequence, or portions thereof, encoding ICEY and their derivatives entirely by synthetic chemistry, after which the gene can be inserted into any of the many available DNA vectors using reagents, vectors and cells that are known in the art at the time of the filing of this application. Moreover, synthetic chemistry may be used to introduce mutations into the icey sequences or any portion thereof. The nucleotide sequence of nucleic acid encoding ICEY can be confirmed through DNA sequencing techniques. Methods for DNA sequencing are well known in the art. Conventional enzymatic methods employed DNA polymerase Klenow fragment, SEQUENASE * (US Biochemical Corp, Cleveland, OH) or Taq polymerase to extend DNA chains from an oligonucleotide primer annealed to the DNA template of interest. Methods have been developed for the use of both single- and double-stranded templates. The chain termination reaction products were electrophoresed on urea-acrylamide gels and detected either by autoradiography (for radionuclide-labeled precursors) or by fluorescence (for fluorescent-labeled precursors) . Recent improvements in mechanized reaction preparation, sequencing and analysis using the fluorescent detection method have permitted expansion in the number of sequences that can be determined per day (using machines such as the Catalyst 800 and the Applied Biosystems 377 or 373 DNA sequencer) . The nucleotide sequence can be used in an assay to detect inflammation or disease associated with abnormal levels of expression of ICEY. The nucleotide sequence can be labeled by methods known in the art and added to a fluid or tissue sample from a patient under hybridizing conditions. After an incubation period, the sample is washed with a compatible fluid which optionally contains a dye (or other label requiring a developer) if the nucleotide has been labeled with an enzyme. After the compatible fluid is rinsed off, the dye is quantified and compared with a standard. If the amount of dye is significantly elevated, the nucleotide sequence has hybridized with the sample, and the assay indicates the presence of inflammation and/or disease. The nucleotide sequence for icey can be used to construct hybridization probes for mapping that gene. The nucleotide sequence provided herein may be mapped to a particular chromosome or to specific regions of that chromosome using well known genetic and/or chromosomal mapping techniques. These techniques include in situ hybridization, linkage analysis against known chromosomal markers, hybridization screening with libraries, flow-sorted chromosomal preparations, or artificial chromosome constructions YAC, PI or BAC constructions. The technique of fluorescent in situ hybridization of chromosome spreads has been described, among other places, in Verma et al (1988) Human Chromosomes: A Manual of Basic Techniques, Pergamon Press, New York City. Fluorescent in situ hybridization of chromosomal preparations and other physical chromosome mapping techniques may be correlated with additional genetic map data. Examples of genetic map data can be found in the 1994 Genome Issue of Science (265:1981f). Correlation between the location of icey on a physical chromosomal map and a specific disease (or predisposition to a specific disease) can help delimit the region of DNA associated with that genetic disease. The nucleotide sequence of the subject invention may be used to detect differences in gene sequence between normal and carrier or affected individuals. Nucleotide sequences encoding ICEY may be used to produce purified ICEY using well known methods of recombinant DNA technology. Among the many publications that teach methods for the expression of genes after they have been isolated is Goeddel (1990) Gene Expression Technology, Methods and Enzymology, Vol 185, Academic Press, San Diego CA. ICEY may be expressed in a variety of host cells, either prokaryotic or eukaryotic. Host cells may be from the same species in which icey nucleotide sequences are endogenous or from a different species. Advantages of producing ICEY by recombinant DNA technology include obtaining adequate amounts of the protein for purification and the availability of simplified purification procedures. Cells transformed with DNA encoding ICEY may be cultured under conditions suitable for the expression of ICEY and recovery of the protein from the cell culture. ICEY produced by a recombinant cell may be secreted or may be contained intracellularly, depending on the ICEY sequence and the genetic construction used. In general, it is more convenient to prepare recombinant proteins in secreted form. Purification steps vary with the production process and the particular protein produced. In addition to recombinant production, fragments of ICEY may be produced by direct peptide synthesis using solid-phase techniques (cf Stewart et al (1969) Solid-Phase Peptide Synthesis, WH Freeman Co, San Francisco CA; Merrifield J (1963) J Am Chem Soc 85:2149-2154. In vitro protein synthesis may be performed using manual techniques or by automation. Automated synthesis may be achieved, for example, using Applied Biosystems 431A Peptide Synthesizer (Foster City, California CA) in accordance with the instructions provided by the manufacturer. Various fragments of ICEY may be chemically synthesized separately and combined using chemical methods to produce the full length molecule. ICEY for antibody induction does not require biological activity; however, the protein must be antigenic. Peptides used to induce specific antibodies may have an amino acid sequence consisting of at least five amino acids and preferably at least 10 amino acids. They should mimic a portion of the amino acid sequence of the protein and may contain the entire amino acid sequence of a small naturally occurring molecule such as ICEY. Short stretches of ICEY amino acid may be fused with those of another protein such as keyhole limpet hemocyanin and the chimeric molecule used for antibody production. Various methods are known to those of skill in the art for preparing monoclonal and polyclonal antibodies to ICEY. In one approach, denatured ICEY from the reverse phase HPLC separation is obtained and used to immunize mice or rabbits using techniques known to those of skill in the art. About 100 micrograms are adequate for immunization of a mouse, while up to 1 mg is used for immunization of a rabbit. For identifying mouse hybridomas, the denatured protein can be radioiodinated and used to screen potential murine B-cell hybridomas for those which produce antibody. This procedure requires only small quantities of protein, such that 20 mg would be sufficient for labeling and screening of several thousand clones. In another approach, the amino acid sequence of ICEY, as deduced from translation of the cDNA sequence, is analyzed to determine regions of high immunogenicity. For example, oligopeptides comprising hydrophilic regions, as shown in Figure 3, can be synthesized and used in suitable immunization protocols to raise antibodies. Analysis to select appropriate epitopes is described by Ausubel FM et al (1989, Current Protocols in Molecular Biology, John Wiley & Sons, NYC) . The optimal amino acid sequences for immunization are usually at the C-terminus, the N-terminus and those intervening, hydrophilic regions of the polypeptide which are likely to be exposed to the external environment when the protein is in its natural conformation. Typically, selected peptides, about 15 residues in length, are synthesized using an Applied Biosystems Peptide Synthesizer Model 431A using fmoc-chemistry and coupled to keyhole limpet hemocyanin (KLH, Sigma) by reaction with M-maleimidobenzoyl-N-hydroxysuccinimide ester (MBS; cf. Ausubel FM et al, supra) . If necessary, a cysteine may be introduced at the N-terminus of the peptide to permit coupling to KLH and animals can be immunized with the peptide-KLH complex in complete Freund's adjuvant. The resulting antisera can be tested for antipeptide activity by binding the peptide to plastic, blocking with 1% BSA, reacting with antisera, washing and reacting with labeled (radioactive or fluorescent) , affinity purified, specific goat anti-rabbit IgG. Hybridomas may also be prepared and screened using standard techniques. Hybridomas of interest can be detected by screening with labeled ICEY to identify those fusions producing the monoclonal antibody with the desired specificity. In a typical protocol, wells of plates (FAST; Becton-Dickinson, Palo Alto, CA) are coated with affinity purified, specific rabbit-anti-mouse (or suitable anti-species Ig) antibodies at 10 mg/ml. The coated wells are blocked with 1% BSA, washed and exposed to supernatants from hybridomas. After incubation, the wells are exposed to labeled ICEY at 1 mg/ml. Clones producing antibodies will bind a quantity of labeled ICEY which is detectable above background. Such clones can be expanded and subjected to 2 cycles of cloning at limiting dilution (1 cell/3 wells) . Cloned hybridomas are injected into pristane-treated mice to produce ascites, and monoclonal antibody can be purified from mouse ascitic fluid by affinity chromatography using Protein A. Monoclonal antibodies with affinities of at least 10 8 M" 1 , preferably 10 9 to 10 10 or stronger, will typically be made by standard procedures as described in Harlow and Lane (1988) Antibodies: A Laboratory Manual. Cold Spring Harbor Laboratory New York; and in Goding (1986) Monoclonal Antibodies: Principles and Practice, Academic Press, New York City, both incorporated herein by reference. Antibodies specific for ICEY may be produced by inoculation of an appropriate animal with the polypeptide or an antigenic fragment. An antibody is specific for ICEY if it is produced against all or a part of ICEY and binds to all or part of ICEY. Induction of antibodies includes not only the stimulation of an immune response by injection into animals, but also analogous steps in the production of synthetic antibodies or other specific-binding molecules such as the screening of recombinant immunoglobulin libraries (Orlandi R et al (1989) PNAS 86:3833-3837, or Huse WD et al (1989) Science 256:1275-1281) or the in vitro stimulation of lymphocyte populations. Current technology (Winter G and Milstein C (1991) Nature 349:293-299) provides for a number of highly specific binding reagents based on the principles of antibody formation. These techniques may be adapted to produce molecules specifically binding ICEY. An additional embodiment of the subject invention is the use of ICEY specific antibodies, inhibitors, receptors or their analogs as bioactive agents to treat activated monocyte disorders, such as inflammatory bowel disease, insulin-dependent diabetes mellitus, rheumatoid arthritis, septic shock and similar pathologic problems. Bioactive compositions comprising agonists, antagonists, receptors or inhibitors of ICEY may be administered in a suitable therapeutic dose determined by any of several methodologies including clinical studies on mammalian species to determine maximal tolerable dose and on normal human subjects to determine safe dose. Additionally, the bioactive agent may be complexed with a variety of well established compounds or compositions which enhance stability or pharmacological properties such as half-life. It is contemplated that the therapeutic, bioactive composition may be delivered into the bloodstream by intravenous infusion or any other effective means which could be used for treating conditions associated with ICEY production and function. Antibodies, inhibitors, or antagonists of ICEY (or other treatments for excessive ICEY production, hereinafter termed "treatments") , can provide different effects when administered therapeutically. Treatments will be formulated in a nontoxic, inert, pharmaceutically acceptable aqueous carrier medium preferably at a pH of about 5 to 8, more preferably 6 to 8, although the pH may vary according to the characteristics of the antibody, inhibitor, or antagonist being formulated and the condition to be treated. Characteristics of treatments for excessive ICEY production include solubility of the molecule, half-life and immunogenicity; these and other characteristics may aid in defining an effective carrier. Native human proteins are preferred as treatments for excessive ICEY production, but organic or synthetic molecules resulting from drug screens may be equally effective in particular situations. Treatments for excessive ICEY production may be delivered by known routes of administration including but not limited to topical creams and gels; transmucosal spray and aerosol, transdermal patch and bandage; injectable, intravenous and lavage formulations; and orally administered liquids and pills, particularly formulated to resist stomach acid and enzymes. The particular formulation, exact dosage, and route of administration will be determined by the attending physician and will vary according to each specific situation. Such determinations are made by considering multiple variables such as the condition to be treated, the treatment to be administered, and the pharmacokinetic profile of the particular treatment. Additional factors which may be taken into account include disease state (e.g. severity) of the patient, age, weight, gender, diet, time of administration, drug combination, reaction sensitivities, and tolerance/response to therapy. Long-acting formulations might be administered only once per day, or even less often: every 3 to 4 days, every week, or every two weeks depending on half-life and clearance rate of the particular treatments. Normal dosage amounts may vary from 0.1 to 100,000 micrograms, up to a total dose of about 1 g, depending upon the route of administration. Guidance as to particular dosages and methods of delivery is provided in the literature; see US Patent Nos. 4,657,760; 5,206,344; or 5,225,212. It is anticipated that different formulations will be effective for different treatments and that systemic administration may necessitate delivery in a manner different from that of local administration to a specific organ or tissue. It is contemplated that conditions or diseases which activate monocytes, macrophages and possibly other leukocytes may precipitate damage that is treatable with antibodies, inhibitors or antagonists of ICEY. Activated monocyte disorders may be specifically diagnosed by the tests discussed infra, and such testing may be performed in suspected cases of inflammatory bowel disease, insulin-dependent diabetes mellitus, rheumatoid arthritis, sepsis and similar physiologic/pathologic problems. The examples below are provided to illustrate the subject invention. These examples are provided by way of illustration and are not included for the purpose of limiting the invention. INDUSTRIAL APPLICABILITY I Isolation of mRNA and Construction of cDNA Libraries The icey sequence was identified among the unique sequences 14775 (SEQ ID Nθ:l) and 157811 (SEQ ID Nθ:2) obtained from human activated THP-1 libraries. THP-1 is a human leukemic cell line derived from the blood of a 1-year-old boy with acute monocytic leukemia. Cells used for the activated (or PMA+LPS) library were cultured for 48 hr with 100 nm PMA in DMSO and for 4 hr with lμg/ l LPS. The activated THP-1 library was custom constructed by Stratagene (Stratagene, 11099 M. Torrey Pines Rd. , La Jolla, CA 92037) essentially as described below. Stratagene prepared the cDNA library using oligo d(T) priming. Synthetic adapter oligonucleotides were ligated onto the cDNA molecules enabling them to be inserted into the Uni-ZAP™ vector system (Stratagene) . This allowed high efficiency unidirectional (sense orientation) lambda library construction and the convenience of a plasmid system with blue/white color selection to detect clones with cDNA insertions. The quality of the cDNA library was screened using DNA probes, and then, the pBluescript ® phagemid (Stratagene) was excised. This phagemid allows the use of a plasmid system for easy insert characterization, sequencing, site-directed mutagenesis, the creation of unidirectional deletions and expression of fusion polypeptides. Subsequently, the custom- constructed library phage particles were infected into E. coli host strain XLl-Blue ® (Stratagene) . The high transformation efficiency of this bacterial strain increases the probability that the cDNA library will contain rare, under-represented clones. Alternative unidirectional vectors might include, but are not limited to, pcDNAI (Invitrogen, San Diego CA) and pSHlox-1 (Novagen, Madison Wl) . II Isolation of cDNA Clones The phagemid forms of individual cDNA clones were obtained by the in vivo excision process, in which XL1-BLUE was coinfected with an fl helper phage. Proteins derived from both lambda phage and fl helper phage initiated new DNA synthesis from defined sequences on the lambda target DNA and create a smaller, single-stranded circular phagemid DNA molecule that includes all DNA sequences of the pBluescript plasmid and the cDNA insert. The phagemid DNA was released from the cells and purified, then used to re-infect fresh bacterial host cells (SOLR, Stratagene Inc) , where the double-stranded phagemid DNA was produced. Because the phagemid carries the gene for β-lactamase, the newly transformed bacteria were selected on medium containing ampicillin. Phagemid DNA was purified using the QIAWELL-8 Plasmid Purification System from QIAGEN ® DNA Purification System. This technique provides a rapid and reliable high-throughput method for lysing the bacterial cells and isolating highly purified phagemid DNA. The DNA eluted from the purification resin was suitable for DNA sequencing and other analytical manipulations. III Sequencing of cDNA Clones The cDNA inserts from random isolates of the THP-1 library were sequenced in part. The cDNAs were sequenced by the method of Sanger F. and AR Coulson (1975; J. Mol. Biol.94:441f) , using a Hamilton Micro Lab 2200 (Hamilton, Reno NV) in combination with four Peltier Thermal Cyclers (PTC200 from MJ Research, Watertown MA) and Applied Biosystems 377 or 373 DNA Sequencing Systems (Perkin Elmer) and reading frame determined. IV Homology Searching of cDNA Clones and Deduced Proteins Each sequence so obtained was compared to sequences in GenBank using a search algorithm developed by Applied Biosystems Inc. and incorporated into the INHERIT™ 670 Sequence Analysis System. In this algorithm, Pattern Specification Language (developed by TRW Inc.) was used to determine regions of homology. The three parameters that determine how the sequence comparisons run were window size, window offset, and error tolerance. Using a combination of these three parameters, the DNA database was searched for sequences containing regions of homology to the query sequence, and the appropriate sequences were scored with an initial value. Subsequently, these homologous regions were examined using dot matrix homology plots to distinguish regions of homology from chance matches. Smith-Waterman alignments of the protein sequence were used to display the results of the homology search. This method did not immediately identify an ICE homolog. Subsequently, the human ICE sequence was obtained from GenBank GI number 717040 and compared with the sequences in the LIFESEQ™ database (Incyte Pharmaceuticals, Inc.). Incyte clones 14775 and 157811 were determined to have homology to the Genbank sequence, GI 717040. The presence of icey in the activated THP-1 library, which represents activated macrophages, is consistent with its expression in tissues with active immunological defenses, particularly inflamed and diseased tissues, including those previously defined relative to activated monocyte disorders. Peptide and protein sequence homologies were ascertained using the INHERIT 670 Sequence Analysis System in a way similar to that used in DNA sequence homologies. Pattern Specification Language and parameter windows were used to search protein databases for sequences containing regions of homology which were scored with an initial value. Dot-matrix homology plots were examined to distinguish regions of significant homology from chance matches. The nucleotide and amino acid sequences for the entire coding region of the human ICE homolog, ICEY, claimed in this invention are shown in Figures 1A and IB. V Identification and Full Length Sequencing of the Genes Incyte clones numbered 14775 and 157811 (SEQ ID NOS 1 and 2, respectively) were resequenced with M13 and M13 reverse primers to obtain additional 3' and 5' nucleotide sequence. The additional sequences did not overlap, indicating that the coding region was incomplete. Because only clone 14775 appeared to have the complete coding region, that clone alone was primed with newly designed oligos (SED ID NOS:3 and 4) to obtain internal sequence to finish the nucleotide sequence of the gene. The additional sequence which had been obtained from clone 157811 was used to confirm and edit the sequences from clone 14775. The confirmed icey sequence was homologous to but clearly different from any known ICE molecule. The complete nucleotide sequence for icey was translated, and the in-frame translation is shown in Figures 1A and IB. When all three possible predicted translations of the sequence were searched against protein databases such as SwissProt and PIR, no exact matches were found to any of the possible translations of icey. Figures 2A and 2B show the comparison of the ICEY amino acid sequence with human ICE GenBank GI number 717040. Amino acids in agreement are highlighted in black. The expected structure (alpha, beta, and flexible regions) , as well as hydrophilicity and antigenicity plots for ICEY are shown as Figure 3. Figure 4 shows the alignments of the completed gene sequence (top line) (SEQ ID NO:5) with the partial cDNA sequences of clones numbered 14775 and 157811 (SEQ ID N0S:1 and 2, respectively) . The sequence alignment of SEQ ID NO:l is shown on the left and that of SEQ ID NO:2 on the right. VI Antisense analysis Knowledge of the correct, complete cDNA sequence of the new icey gene will enable its use in antisense technology in the investigation of gene function. Oligonucleotides, genomic or cDNA fragments comprising the antisense strand of icey are used either in vitro or in vivo to inhibit expression of the protein. Such technology is now well known in the art, and probes are designed at various locations along the icey nucleotide sequence. By treatment of cells or whole test animals with such antisense sequences, the gene of interest can effectively be turned off. Frequently, the function of the gene is ascertained by observing behavior at the cellular, tissue or organismal level (e.g. lethality, loss of differentiated function or changes in morphology, for example) . In addition to using sequences constructed to interrupt transcription of the open reading frame, modifications of gene expression is obtained by designing antisense sequences to intron regions, promoter/enhancer elements, or even to trans-acting regulatory genes. Similarly, inhibition of activity is achieved using Hogeboom base-pairing methodology, also known as "triple helix" base pairing. VII Expression of ICEY Expression of icey is accomplished by subcloning the cDNAs into appropriate expression vectors and transfecting the vectors into appropriate expression hosts. The cloning vector used for the generation of the tissue library is used for expression of the icey sequence in £__. coli. Upstream of the cloning site, this vector contains a promoter for β-galactosidase, followed by nucleotide sequence encoding the amino terminal Met and the subsequent 7 residues of β-galactosidase. Immediately following these eight residues is an engineered bacteriophage promoter useful for artificial priming and transcription and a number of unique restriction sites, including Eco RI, for cloning. Induction of the isolated, transfected bacterial strain with IPTG using standard methods produces a fusion protein corresponding to the first seven residues of β-galactosidase, about 15 residues of "linker", and the protein encoded by the cDNA. Since cDNA clone inserts are generated by an essentially random process, there is one chance in three that the included cDNA will lie in the correct frame for proper translation. If the cDNA is not in the proper reading frame, the proper reading frame is obtained by deletion or insertion of the appropriate number of bases by well known methods including in vitro mutagenesis, digestion with exonuclease III or mung bean nuclease, or oligonucleotide linker inclusion. The icey cDNA is shuttled into other vectors known to be useful for expression of protein in specific hosts. Oligonucleotide amplimers containing cloning sites as well as a segment of DNA sufficient to hybridize to stretches at both ends of the target cDNA (25 bases) is synthesized chemically by standard methods. These primers are used to amplify the desired gene segments by PCR. The resulting new gene segments are digested with appropriate restriction enzymes under standard conditions and isolated by gel electrophoresis. Alternately, similar gene segments are produced by digesting the cDNA with appropriate restriction enzymes and filling in the missing gene segments with chemically synthesized oligonucleotides. Segments of the coding sequence from more than one gene are ligated together and cloned in appropriate vectors to optimize expression of recombinant sequence. Suitable expression hosts for such chimeric molecules include but are not limited to mammalian cells such as Chinese Hamster Ovary (CHO) and human 293 cells, insect cells such as Sf9 cells, yeast cells such as Saccharomyces cerevisiae, and bacteria such as E. coli. For each of these cell systems, a useful expression vector also includes an origin of replication to allow propagation in bacteria and a selectable marker, such as the β-lactamase antibiotic resistance gene, to allow selection in bacteria. In addition, the vectors may include a second selectable marker such as the neomycin phosphotransferase gene to allow selection in transfected eukaryotic host cells. Vectors for use in eukaryotic expression hosts may require RNA processing elements such as 3' polyadenylation sequences if such are not part of the cDNA of interest. Additionally, the vector may contain promoters or enhancers which increase gene expression. Such promoters are host specific and include MMTV, SV40, or metallothionine promoters for CHO cells; trp, lac, tac or T7 promoters for bacterial hosts; or alpha factor, alcohol oxidase or PGH promoters for yeast. Transcription enhancers, such as the rous sarcoma virus (RSV) enhancer, are used in mammalian host cells. Once homogeneous cultures of recombinant cells are obtained through standard culture methods, large quantities of recombinantly produced ICEY are recovered from the conditioned medium and analyzed using chromatographic methods known in the art. Because expression of the ICEY protein may be lethal to certain cell types, care should be given to the selection of a suitable host species and growth conditions. Alternately, the protein is expressed in the inactive form, such as in inclusion bodies. The inclusion bodies are separated from the cells, the protein solubilized and refolded into an active form. VIII Isolation of Recombinant ICEY Purification of ICEY is accomplished by creating a chimeric protein having one or more polypeptide domains added to the ICEY amino acids to facilitate protein purification. Such purification facilitating domains include, but are not limited to, metal chelating peptides such as histidine-tryptophan modules that allow purification on immobilized metals, protein A domains that allow purification on immobilized immunoglobulin, and the domain utilized in the FLAGS extension/affinity purification system (Immunex Corp., Seattle WA) . The inclusion of a cleavable linker sequence such as Factor XA or enterokinase (Invitrogen, San Diego CA) between the purification domain and the icey sequence is used to purify ICEY from the fusion protein complex. IX Diagnostic Test Using ICEY Specific Antibodies Particular ICEY antibodies are useful for the diagnosis of prepathologic conditions, and chronic or acute diseases which are characterized by differences in the amount or distribution of ICEY. ICEY has been found in the activated THP-1 library and is thus associated with abnormalities or pathologies which activate monocytes. Diagnostic tests for ICEY include methods utilizing the antibody and a label to detect ICEY in human body fluids, tissues or extracts of such tissues. The polypeptides and antibodies of the present invention are used with or without modification. Frequently, the polypeptides and antibodies will be labeled by joining them, either covalently or noncovalently, with a substance which provides for a detectable signal. A wide variety of labels and conjugation techniques are known and have been reported extensively in both the scientific and patent literature. Suitable labels include radionuclides, enzymes, substrates, cofactors, inhibitors, fluorescent agents, chemiluminescent agents, magnetic particles and the like. Patents teaching the use of such labels include US Patent Nos. 3,817,837; 3,850,752; 3,939,350; 3,996,345; 4,277,437; 4,275,149; and 4,366,241. Also, recombinant immunoglobulins may be produced as shown in US Patent No. 4,816,567, incorporated herein by reference. A variety of protocols for measuring soluble or membrane-bound ICEY, using either polyclonal or monoclonal antibodies specific for the respective protein are known in the art. Examples include enzyme-linked immunosorbent assay (ELISA) , radioimmunoassay (RIA) and fluorescent activated cell sorting (FACS) . A two-site monoclonal-based immunoassay utilizing monoclonal antibodies reactive to two non-interfering epitopes on ICEY is preferred, but a competitive binding assay can be employed. These assays are described, among other places, in Maddox, DE et al (1983, J Exp Med 158:1211) . X Purification of Native ICEY Using Specific Antibodies Native or recombinant ICEY is purified by immunoaffinity chromatography using antibodies specific for ICEY. In general, an immunoaffinity column is constructed by covalently coupling the anti-ICEY antibody to an activated chromatographic resin. Polyclonal immunoglobulins are prepared from immune sera either by precipitation with ammonium sulfate or by purification on immobilized Protein A (Pharmacia LKB Biotechnology, Piscataway, NJ) . Monoclonal antibodies are prepared from mouse ascites fluid by ammonium sulfate precipitation or chromatography on immobilized Protein A. Partially purified immunoglobulin is covalently attached to a chromatographic resin such as CnBr-activated Sepharose (Pharmacia LKB Biotechnology) . The antibody is coupled to the resin, the resin is blocked, and the derivative resin is washed according to the manufacturer's instructions. Such immunoaffinity columns are utilized in the purification of ICEY by preparing a fraction from cells containing ICEY in a soluble form. This preparation is derived by solubilization of the whole cell or of a subcellular fraction obtained via differential centrifugation by the addition of detergent or by other methods well known in the art. Alternatively, soluble ICEY containing a signal sequence is secreted in useful quantity into the medium in which the cells are grown. A soluble ICEY-containing preparation is passed over the immunoaffinity column, and the column is washed under conditions that allow the preferential absorbance of ICEY (eg, high ionic strength buffers in the presence of detergent) . Then, the column is eluted under conditions that disrupt antibody/ICEY binding (e.g., a buffer of pH 2-3 or a high concentration of a chaotrope such as urea or thiocyanate ion) , and ICEY is collected. XI ICEY Activity The activity of purified or expressed ICEY is tested by methods known to those of skill in the art. One such method calls for stimulating macrophages with LPS to induce the expression of pre-IL-lβ and then treating with ATP and ICEY. Mature IL-lβ levels in the medium are measured by enzyme-linked immunosorbent assay (ELISA) , as described in Li et al. (1995) Cell 80:401-411. XII Drug Screening ICEY, or biologically or immunologically active fragments thereof, are used for screening compounds in any of a variety of drug screening techniques. The ICEY polypeptide or f agment employed in such a test is either free in solution, affixed to a solid support, borne on a cell surface or located intracellularly. One method of drug screening utilizes eukaryotic or prokaryotic host cells which are stably transformed with recombinant nucleic acids expressing ICEY or a fragment thereof. Drugs are screened against such transformed cells in competitive binding assays. Such cells, either in viable or fixed form, can be used for standard binding assays. One may measure, for example, the formation of complexes between ICEY and the agent being tested. Alternatively, one can examine the diminution in complex formation between ICEY and its target cell, the monocyte or macrophage, caused by the agent being tested. Thus, the present invention provides methods of screening for drugs, natural inhibitors or any other agents which can affect inflammation and disease. These methods comprise contacting such an agent with a ICEY polypeptide or fragment thereof and assaying 1) for the presence of a complex between the agent and the ICEY polypeptide or fragment, or 2) for the presence of a complex between the ICEY polypeptide or fragment and the cell, by methods well known in the art. In such competitive binding assays, the ICEY polypeptide or fragment is typically labeled. After suitable incubation, free ICEY polypeptide or fragment is separated from that present in bound form, and the amount of free or uncomplexed label is a measure of the ability of the particular agent to bind to ICEY or to interfere with the ICEY/cell complex and agent complex. Another technique for drug screening provides high throughput screening for compounds having suitable binding affinity to the ICEY polypeptide and is described in detail in European Patent Application 84/03564, published on September 13, 1984, incorporated herein by reference. Briefly stated, a plurality of different peptide test compounds are synthesized on a solid substrate, such as plastic pins or some other surface. The peptide test compounds are reacted with ICEY polypeptide and washed. Bound ICEY polypeptide is then detected by methods well known in the art. Purified ICEY can also be coated directly onto plates for use in the aforementioned drug screening techniques. In addition, non-neutralizing antibodies can be used to capture the peptide and immobilize it on the solid support. This invention also contemplates the use of competitive drug screening assays in which neutralizing antibodies capable of binding ICEY specifically compete with a test compound for binding to ICEY polypeptides or fragments thereof. In this manner, the antibodies can be used to detect the presence of any peptide which shares one or more antigenic determinants with ICEY. XIV Rational Drug Design The goal of rational drug design is to produce structural analogs of biologically active polypeptides of interest or of small molecules with which they interact, e.g., agonists, antagonists, or inhibitors. Any of these examples can be used to fashion drugs which are more active or stable forms of the polypeptide or which enhance or interfere with the function of a polypeptide in vivo (cf Hodgson J (1991) Bio/Technology 9:19-21, incorporated herein by reference) . In one approach, the three-dimensional structure of a protein of interest, or of a protein-inhibitor complex, is determined by x-ray crystallography, by computer modeling or, most typically, by a combination of the two approaches. Both the shape and charges of the polypeptide must be ascertained to elucidate the structure and to determine active site(s) of the molecule. Useful information regarding the structure of a polypeptide may be gained by modeling based on the structure of homologous proteins. The crystal structure of an ICE protein (Walker, 1994, supra) can be used as a starting point. Relevant structural information is used to design analogous ICEY-like molecules or to identify efficient inhibitors. Useful examples of rational drug design include molecules which have different specificity or improved activity or stability as shown by Braxton S and Wells JA (1992 Biochemistry 31:7796-7801) or which act as inhibitors, agonists, or antagonists of native peptides as shown by Athauda SB et al (1993 J Biochem 113:742-746), incorporated herein by reference. It is also possible to isolate a target-specific antibody, selected by functional assay, as described above, and to solve its crystal structure. This approach, in principle, yields a pharmacore upon which subsequent drug design can be based. It is possible to bypass protein crystallography altogether by generating anti-idiotypic antibodies (anti-ids) to a functional, pharmacologically active antibody. As a mirror image of a mirror image, the binding site of the anti-ids would be expected to be an analog of the original receptor. The anti-id could then be used to identify and isolate peptides from banks of chemically or biologically produced peptides. The isolated peptides would then act as the pharmacore. Using methods described infr . a sufficient amount of ICEY may be made available to perform such analytical studies as X-ray crystallography. In addition, knowledge of the ICEY amino acid sequence provided herein will provide guidance to those employing computer modeling techniques in place of or in addition to x-ray crystallography. All publications and patents mentioned in the above specification are herein incorporated by reference. The foregoing written specification is considered to be sufficient to enable one skilled in the art to practice the invention. Indeed, various modifications of the above described modes for carrying out the invention which are readily apparent to those skilled in the field of molecular biology or related fields are intended to be within the scope of the following claims. SEQUENCE LISTING (1) GENERAL INFORMATION: (i) APPLICANT: INCYTE PHARMACEUTICALS, INC. (ii) TITLE OF INVENTION: HUMAN ICE HOMOLOG (iii) NUMBER OF SEQUENCES:6 (iv) CORRESPONDENCE ADDRESS: (A) ADDRESSEE: INCYTE PHARMACEUTICALS, INC. (B) STREET: 3330 Hillview Avenue (C) CITY: Palo Alto (D) STATE: CA (E) COUNTRY: USA (F) ZIP: 94304 (V) COMPUTER READABLE FORM: (A) MEDIUM TYPE: Floppy disk (B) COMPUTER: IBM PC compatible (C) OPERATING SYSTEM: PC-DOS/MS-DOS (D) SOFTWARE: Patentln Release #1.0, Version #1.30 (vi) CURRENT APPLICATION DATA: (A) APPLICATION NUMBER: To Be Assigned (B) FILING DATE: Filed Herewith (vii) PRIOR APPLICATION DATA: (A) APPLICATION SERIAL NO: 08/443,865 (B) FILING DATE: 31-MAY-1995 (viii) ATTORNEY/AGENT INFORMATION: (A) NAME: LUTHER, BARBARA J. (B) REGISTRATION NUMBER: 33954 (C) REFERENCE/DOCKET NUMBER: PF-0037 PCT (ix) TELECOMMUNICATION INFORMATION: (A) TELEPHONE: 415-855-0555 (B) TELEFAX: 415-852-0195 (2) INFORMATION FOR SEQ ID NO:l: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 303 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (vii) IMMEDIATE SOURCE: (A) LIBRARY: THP-1 (B) CLONE: 014775 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:l: ACAGTCTTTA CTTTTATTGA AATACCAAAT ATTGACTATG CAAGCTATAC TGGTAAATGT 60 CTCTTTGATG TTGACAGAGG AGGGCTGGGC TGCCTGTGGT TTCATTTTCA ATTGCCAGGA 120 AAGAGGTAGA AATCTCTTGT CAAGGTTGCT CGTTCTATGG TGGGCATCTG GGCTTTAGCC 180 TGTGGAACTT CAAATGATTT CTGTACCTTC CGAAATATTT CCATTAGGTG GCAGCAGCAA 240 GAATATTTCT GGAAGCATGT GATGAGTTCC GTAATGAGAT GGAGCCCCTT TGCGGTCTCT 300 TTC 303 (2) INFORMATION FOR SEQ ID NO:2: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 167 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (vi) ORIGINAL SOURCE: (E) HAPLOTYPE: THP-1 (vii) IMMEDIATE SOURCE: (A) LIBRARY: 157811 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2: CAAACACTTC TCAATATGGA CCAAAAGATC ACCAGTGTAA AACCTCTTCT GCAAATCGAG 60 GCTGGCCACC TGCAGCAGAT CTCAAATATA CTCAAACTTT GTCCTCGTGA AGAATTCCTG 120 AGACTGTGTA AAAAAAATCA TGATGAGATC TATCCAATAA AAAAGAG 167 (2) INFORMATION FOR SEQ ID NO:3: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 23 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: CDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3: CCCCCAGGTT CTCAGATGAC TGT 23 (2) INFORMATION FOR SEQ ID NO:4: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 23 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: cDNA (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4: ACAGTCATCT GAGAACCTGG GGG 23 (2) INFORMATION FOR SEQ ID NO:5: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 1274 base pairs (B) TYPE: nucleic acid (C) STRANDEDNESS: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: DNA (genomic) (vii) IMMEDIATE SOURCE: (A) LIBRARY: THP-1 (B) CLONE: 14775 (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5: TGCATTCGGA CGAGGTTAGC TATGGCTGAA GACAACCACA AAAAAAAAAC AGTTAAGATG 60 TTGGAATACC TGGGCAAAGA TGTTCTTCAT GGTGTTTTTA ATTATTTGGC AAAACACGAT 120 GTTCTGACAT TGAAGGAAGA GGAAAAGAAA AAATATTATG ATACCAAAAT TGAAGACAAG 180 GCCCTGATCT TGGTAGACTC TTTGGAAAGA ATCGCGTGGT CATCAAATGT TTACCCAAAC 240 ACTTCTCAAT ATGGACCAAA AGATCACCAG TGTAAAACCT CTTCTGCAAA TCGAGGTGGA 300 CCACCTGAGT CAGCAGAATC TACAAATATA CTCAAACTTT GTCCTCGTGA AGAATTCCTG 360 AGACTGTGTA AAAAAAATCA TGATGAGATC TATCCAATAA AAAAGAGAGA GGACCGCAGA 420 CGCCTGGCTC TCATCATATG CAATACAAAG TTTGATCACC TGCCTGCAAG GAATGGGGCT 480 CACTATGACA TCGTGGGGAT GAAAAGGCTG CTTCAAGGCC TGGGCTACAC TGTGGTTGCC 540 GAAAAGAATC TCACAGCCAG GGATATGGAG TCAGTGCTGA GGGCATTTGC TGCCAGACCA 600 GAGCACAAGT CCTCTGACAG CACGTTCTTG GTACTCATGT CTCATGGCAT CCTAGAGGGA 660 ATCTGCGGAC CTGCGCATAA AAAGAAAAAA CCGGATGTGC TGCTTTATGA CACCATCTTC 720 CAGATATTCA ACAACCGCAA CTGCCTCAGT CTAAAGGACA AACCCAAGGT CATCATTGTC 780 CAGGCCTGCA GAGGTGAAAA ACATGGGAAC TCTGGTCAGA GACTCTCCAC ACCTTGCATC 840 ATCTCTTCAC AGTCATCTGA GAACCTGGAG GCAGATTCTG TTTTCAAGAC CCCGAGGAGA 900 AGGACTTCAT TGCTGTTCTG TTCTTCAACA CCACATAACG TGTCCTGGAG AGACCGCACA 960 AGGGGCTCCA TCTTCATTGG GGAACTCATG CACATGCTTC CAGAAATATT CTTCTCTCCA 1020 CCTAATGGAA ATATTTCGGA GGTACAGAAA TCATTTGAAG TTCCACAGGC TAAAGCCCAG 1080 ATGCCCACCA TAGAACGAGC AACCTTGACA AGAGATTTCT ACCTCTTTCC TGGCAATTGA 1140 AAATGAAACC ACAGGCAGCC CAGCCCTCCT CTGTCAACAT CAAAGAGCAC ATTTACCAGT 1200 ATAGCTTGCA TAGTCAATAT TTGGTATTTC AATAAAAGTA AAGACTGTAT CTTTTTAAAA 1260 AAAAAAAAAA AAAA 1274 (2) INFORMATION FOR SEQ ID NO:6: (i) SEQUENCE CHARACTERISTICS: (A) LENGTH: 372 amino acids (B) TYPE: amino acid (D) TOPOLOGY: linear (ii) MOLECULE TYPE: protein (xi) SEQUENCE DESCRIPTION: SEQ ID NO:6 Met Ala Glu Asp Asn His Lys Lys Lys Thr Val Lys Met Leu Glu Tyr 1 5 10 15 Leu Gly Lys Asp Val Leu His Gly Val Phe Asn Tyr Leu Ala Lys His 20 25 30 Asp Val Leu Thr Leu Lys Glu Glu Glu Lys Lys Lys Tyr Tyr Asp Thr 35 40 45 Lys lie Glu Asp Lys Ala Leu lie Leu Val Asp Ser Leu Glu Arg lie 50 55 60 Ala Trp Ser Ser Asn Val Tyr Pro Asn Thr Ser Gin Tyr Gly Pro Lys 65 70 75 80 Asp His Gin Cys Lys Thr Ser Ser Ala Asn Arg Gly Gly Pro Pro Glu 85 90 95 Ser Ala Glu Ser Thr Asn lie Leu Lys Leu Cys Pro Arg Glu Glu Phe 100 105 110 Leu Arg Leu Cys Lys Lys Asn His Asp Glu lie Tyr Pro lie Lys Lys 115 120 125 Arg Glu Asp Arg Arg Arg Leu Ala Leu lie lie Cys Asn Thr Lys Phe 130 135 140 Asp His Leu Pro Ala Arg Asn Gly Ala His Tyr Asp lie Val Gly Met 145 150 155 160 Lys Arg Leu Leu Gin Gly Leu Gly Tyr Thr Val Val Ala Glu Lys Asn 165 170 175 Leu Thr Ala Arg Asp Met Glu Ser Val Leu Arg Ala Phe Ala Ala Arg 180 185 190 Pro Glu His Lys Ser Ser Asp Ser Thr Phe Leu Val Leu Met Ser His 195 200 205 Gly He Leu Glu Gly He Cys Gly Pro Ala His Lys Lys Lys Lys Pro 210 215 220 Asp Val Leu Leu Tyr Asp Thr He Phe Gin He Phe Asn Asn Arg Asn 225 230 235 240 Cys Leu Ser Leu Lys Asp Lys Pro Lys Val He He Val Gin Ala Cys 245 250 255 Arg Gly Glu Lys His Gly Asn Ser Gly Gin Arg Leu Ser Thr Pro Cys 260 265 270 He He Ser Ser Gin Ser Ser Glu Asn Leu Glu Ala Asp Ser Val Phe 275 280 285 Lys Thr Pro Arg Arg Arg Thr Ser Leu Leu Phe Cys Ser Ser Thr Pro 290 295 300 His Asn Val Ser Trp Arg Asp Arg Thr Arg Gly Ser He Phe He Gly 305 310 315 320 Glu Leu Met His Met Leu Pro Glu He Phe Phe Ser Pro Pro Asn Gly 325 330 335 Asn He Ser Glu Val Gin Lys Ser Phe Glu Val Pro Gin Ala Lys Ala 340 345 350 Gin Met Pro Thr He Glu Arg Ala Thr Leu Thr Arg Asp Phe Tyr Leu 355 360 365 Phe Pro Gly Asn 370

Claims: CLAIMS 1. A purified polynucleotide comprising a nucleic acid sequence encoding the polypeptide having the sequence as depicted in SEQ ID NO:6, or its complement. 2. The polynucleotide of Claim 1 wherein the nucleic acid sequence consists of SEQ ID NO:5. 3. An expression vector comprising the polynucleotide of Claim 2. 4. A host cell comprising the expression vector of Claim 3. 5. A nucleic acid probe comprising a non-conserved fragment of the polynucleotide of Claim 2. 6. An antisense molecule comprising a polynucleotide sequence complementary to at least a portion of the polynucleotide of Claim 2. 7. A method for producing a polypeptide comprising the sequence as depicted in SEQ ID NO:6, said method comprising: a) culturing the host cells of Claim 4 under conditions suitable for the expression of the polypeptide, and b) recovering said polypeptide from the cell culture. 8. A purified Interleukin Converting Enzyme homolog (ICEY) having the amino acid sequence as depicted in SEQ ID NO:6. 9. An antibody specific for the purified polypeptide of Claim 8. 10. A diagnostic composition for the detection of nucleic acid sequences encoding Interleukin Converting Enzyme homolog (ICEY) comprising the nucleic acid probe of Claim 5. 11. A diagnostic test for the detection of nucleotide sequences encoding Interleukin Converting Enzyme homolog (ICEY) in a biological sample, comprising the steps of: a) combining the biological sample with a polynucleotide which comprises the nucleotide sequence of SEQ ID NO:5 or a fragment thereof, wherein said fragment is derived from a non-conserved region of said nucleotide, under conditions suitable for the formation of a nucleic acid hybridization complex between the nucleic acid sequence of SEQ ID NO:5 and a complementary nucleic acid sequence in said sample; b) detecting said hybridization complex; and c) comparing the amount of said hybridization complex with a standard wherein the presence of an abnormal level of said hybridization complex correlates positively with a condition associated with inflammation. 12. The diagnostic test of Claim 12 wherein the polynucleotide is labeled with a reporter molecule and the hybridization complex is detected by measuring said reporter molecule. 13. A diagnostic test for the detection of nucleotide sequences encoding Interleukin Converting Enzyme homolog (ICEY) in a biological sample, comprising the steps of: a)combining the biological sample with polymerase chain reaction primers under conditions suitable for nucleic acid amplification, wherein said primers comprise fragments from non-conserved regions of the nucleotide sequence of SEQ ID NO:5; b) detecting amplified nucleotide sequences; and c) comparing the amount of amplified nucleotide sequences in said biological sample with a standard thereby determining whether the amount of said nucleotide sequence varies from said standard, wherein the presence of an abnormal level of said nucleotide sequence correlates positively with a condition associated with inflammation. 14. A method of screening a plurality of compounds for specific binding affinity with the polypeptide of Claim 8 or any portion thereof, comprising the steps of : a) providing a plurality of compounds; b) combining Interleukin Converting Enzyme homolog (ICEY) with each of a plurality of compounds for a time sufficient to allow binding under suitable conditions; and c) detecting binding of ICEY to each of the plurality of compounds, thereby identifying the compounds which specifically bind ICEY.

Inventors: BRAXTON SCOTT MICHAEL, DELEGEANE ANGELO M, DIEP DINH, BRAXTON, SCOTT, MICHAEL, DELEGEANE, ANGELO, M., DIEP, DINH
Applicants: BRAXTON SCOTT MICHAEL, DELEGEANE ANGELO M, DIEP DINH, INCYTE PHARMA INC, BRAXTON, SCOTT, MICHAEL, DELEGEANE, ANGELO, M., DIEP, DINH, INCYTE PHARMACEUTICALS, INC.
Application year: 1996
Main classification: C12N15
IPC codes: C07K16, C12N1, C12N9, C12N15, C12P21, C12Q1, C12R1