IMMUNOMODULATORY METHODS USING OLIGOSACCHARIDES

Abstract: Methods for modulating immune responses are provided. The methods involve contacting an immune cell with an agent that modulates interaction of a compound comprising a Lewis antigen with the immune cell such that production by the immune cell of at least one cytokine that regulates development of a T helper type 1 or T helper type 2 response is modulated. In one embodiment, the agent is a stimulatory form of a compound comprising a Lewis antigen, such as a Lewis<y>, Lewis<x> or Lewis<a> oligosaccharide, or a derivative thereof. In another embodiment, the agent is an inhibitory form of a compound comprising a Lewis antigen, such as a Lewis<y>, Lewis<x> or Lewis<a> oligosaccharide, or a derivative thereof. In various embodiments, the immune cell is a human immune cell, a macrophage, a T cell or a non-T, non-B spleen cell. In a preferred embodiment, the invention provides methods of stimulating a specific immune response to an antigne in vivo using a stimulatory agent of the invention. In another preferred embodiment, the invention provides methods for inhibiting allergic responses in vivo using an inhibitory agent of the invention. Pharmaceutical compositions for modulating immune responses comprising the stimulatory or inhibitory agents of the invention are also provided.

Description: IMMUNOMODULATORY METHODS USING OLIGOSACCHARIDES Background of the Invention The T lymphocyte compartment ofthe immune system can be divided into a variety of cell subsets. For example, CD4 + T cells represent the T helper cell subset, whereas CD8 + T cells represent the cytotoxic T cell subset. Additionally, CD4 " T helper cells mature into distinct subpopulations that produce different panels of cytokines: the T helper type 1 (Thl) subset produces interleukin-2 (IL-2), interferon-γ (IFN-γ) and tumor necrosis factor-β (TNF-β), whereas the T helper type 2 (Th2) subset produces interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-6 (IL-6) and interleukin- 10 (IL-10). The Thl and Th2 subsets also have differing functional activities. Thl cells are involved in inducing delayed type hypersensitivity responses, whereas Th2 cells are involved in providing efficient "help" to B lymphocytes and stimulate production of IgGl and IgE antibodies. For a review of Thl and Th2 subsets, see Seder, R.A. and Paul, W.E. (1994) Ann. Rev. Immunol. 12:635-673. Cytokines are thought to play a dominant role in controlling the differentiation of T helper precursors (Thp) to either the Thl or Th2 lineage. Thl -associated cytokines, such as IFN-γ, can enhance the development of Thl cells and inhibit the development of Th2 cells, whereas Th2-associated cytokines, such as IL-4 and IL-10, can enhance the development of Th2 cells and inhibit the development of Thl cells. Thus, cytokines can reciprocally regulate the development and/or progression of either a Thl or a Th2 response. The course of certain disease states is influenced by whether a predominant Thl response or Th2 response is mounted. For example, in experimental leishmania infections in mice, animals that are resistant to infection mount predominantly a Thl response, whereas animals that are susceptible to progressive infection mount predominantly a Th2 response (Heinzel, F.P., et al. (1989) J Exp. Med. 169:59-72; Locksley, R. M. and Scott, P. (1992) Immunoparasitology Today J . :A58-A61). In murine schistosomiasis, a Thl to Th2 switch is observed coincident with the release of eggs into the tissues by female parasites and is associated with a worsening ofthe disease condition (Pearce, E.J., et al. (1991) . Exp. Med. 173:159-166; Grzych, J-M, et al. (1991) J. Immunol. 111:1322-1327; Kullberg, M.C., et al. (1992) J. Immunol. 148:3264-3270). Many human diseases, including chronic infections (such as with human immunodeficiency virus (HIV) or tuberculosis) and certain metastatic carcinomas, also are characterized by a Thl to Th2 switch, with elevated expression of IL-10 (see e.g., Shearer, G.M. and Clerici, M. (1992) Prog. Chem. Immunol 54:21 -43; Clerici, M and Shearer, G.M. (1993) Immunology Today 14:107-1 1 1; Yamamura, M., et al. (1993) J. Clin. Invest. 91:1005-1010; Pisa, P., et al. (1992) Proc. Natl. Acad Sci. USA 89:7708-7712; Fauci, A.S. (1988) Science 239:617-623). Furthermore, certain autoimmune diseases have been shown to be associated with a predominant Thl response. For example, patients with rheumatoid arthritis have predominantly Thl cells in synovial tissue (Simon, A.K., et al. (1994) Proc. Natl. Acad. Sci. USA 91:8562-8566) and experimental autoimmune encephalomyelitis (EAE) can be induced by autoreactive Thl cells (Kuchroo, V.K., et al. (1993) J. Immunol. 151 :4371-4381). Velupillai and Harn (Proc. Natl. Acad. Sci. USA (1994) 9 18-22) have shown that schistosome egg antigen (SEA), which expresses the Lewis x antigen, and conjugates ofthe Lewis x antigen, can stimulate IL-10 production in vitro by B cells from Schistosoma mansoni infected mice, but not B cells from uninfected mice, suggesting that during the course of S. mansoni infection, the observed Thl to Th2 shift may results from IL-10 production by B cells induced by SEA. The significance of these observations beyond the particular S. mansoni system used, however, is unclear. For example, this work did not demonstrate whether human immune cells (e.g., human immune cells in the absence of S. mansoni infection) were responsive to Lewis antigen- containing compounds, nor whether cell types other than B cells, such as macrophages or T cells, could produce IL-10 in response to stimulation with compounds comprising a Lewis antigen in the absence of S. mansoni infection. Moreover, this work did not demonstrate whether Lewis antigen-containing compounds could stimulate production of other cytokines that regulate development of Thl and Th2 responses, such as IL-4 or IL-5. Still further, this work did not demonstrate whether Lewis antigen-containing compounds were capable of modulating immune responses in vivo. Summary of the Invention Given the role of either Thl or Th2 cells in the development or progression of many disease states, methods for influencing whether a Thl or Th2 response is mounted are desirable for a variety of clinical situations. This invention provide methods for modulating immune responses by modulating the interaction of immune cells with a compound comprising a Lewis antigen such that production by the immune cells of at least one cytokine that regulates development of a Thl or Th2 response is modulated. In particularly preferred embodiments, the methods of the invention can be used to stimulate an antigen-specific immune response in a subject (i.e., the compounds ofthe invention can be used as adjuvants) or to inhibit allergic responses in a subject. The methods ofthe invention further can be applied to other clinical situations, including autoimmune disorders, cancer and infectious diseases. The invention is based, at least in part, on the discovery that stimulation of a variety of cell types, including human immune cells, T cells, macrophages and non-T, non-B splenic cells with Lewis antigen-containing conjugates results in the production of cytokines that regulate the development of Thl or a Th2 response. Moreover, it has now been discovered that human immune cells are sensitive to stimulation by Lewis v antigen-containing conjugates, that cells from human allergy patients and cancer patients show responsiveness to Lewis antigens and that even normal human peripheral blood mononuclear cells are responsive to stimulation with Lewis-antigen containing compounds. It further has been discovered that Lewis antigen-containing conjugates can be used to stimulate production of a variety of Th2-associated cytokines, including IL- 10, IL-4 and IL-5. It still further has been discovered that administration of Lewis- antigen containing compounds is effective for modulating immune responses in vivo. For example, stimulatory forms ofthe Lewis-antigen containing compounds ofthe invention can be administered to a subject to promote an antigen-specific immune response (e.g., antigen-specific IgG responses) in the subject. Alternatively, inhibitory forms ofthe Lewis-antigen containing compounds ofthe invention can be administered to a subject to inhibit IgE responses in the subject (e.g., in the treatment of allergies). In one embodiment, the invention provides an immunomodulatory method comprising contacting a human immune cell with an agent that modulates interaction of a compound comprising a Lewis antigen with the human immune cell such that production by the human immune cell of at least one cytokine that regulates development of a Thl or Th2 response is modulated. The human immune cell can be, for example, a T cell, a macrophage or a B cell. In another embodiment, the invention provides an immunomodulatory method comprising contacting a macrophage with an agent that modulates interaction of a compound comprising a Lewis antigen with the macrophage such that production by the macrophage of at least one cytokine that regulates development of a Thl or Th2 response is modulated. In yet another embodiment, the invention provides an immunomodulatory method comprising contacting a T cell with an agent that modulates interaction of a compound comprising a Lewis antigen with the T cell such that production by the T cell of at least one cytokine that regulates development of a Thl or Th2 response is modulated. In one embodiment ofthe immunomodulatory methods ofthe invention, production by immune cells of at least one cytokine (preferably IL-10 or IL-4) that regulates development of a Thl or Th2 response is stimulated. In this embodiment, the agent with which the immune cells are contacted preferably is a stimulatory form of a compound comprising a Lewis antigen, such as a compound comprising cross-linked (i.e., multivalent) Lewis v oligosaccharides, Lewis x oligosaccharides, Lewis 3 oligosaccharides or derivatives thereof (e.g., sulfated, sialylated or sulfo-sialylated forms of these oligosaccharides). The stimulatory compound can be, for example, a conjugate ofthe Lewis antigen and a carrier molecule (e.g., human serum albumin or polyacrylamide). For stimulating responses by human immune cells, the agent preferably comprises a Lewis v oligosaccharide or a derivative thereof. In another embodiment ofthe immunomodulatory methods ofthe invention, production by immune cells of at least one cytokine (preferably IL- 10 or IL-4) that regulates development of a Thl or Th2 response is inhibited. In this embodiment, the agent with which the immune cells are contacted preferably is an inhibitory form of a compound comprising a Lewis antigen, such as a soluble, monovaient (i.e.. non- crosslinked) form of a Lewis v oligosaccharide, a Lewis x oligosaccharide, a Lewis a oligosaccharide or a derivative thereof (e.g. , sulfated, sialylated or sulfo-sialylated forms of these oligosaccharides). For inhibiting responses by human immune cells, the agent preferably comprises a Lewis v oligosaccharide or a derivative thereof. The stimulatory or inhibitory compounds ofthe invention can be contacted with immune cells in vitro to produce one or more cytokines that regulate the development of a Thl or Th2 response. After in vitro stimulation, the immune cells can be administered to a subject to influence whether a Thl or a Th2 response predominates in the subject. Alternatively, a stimulatory or inhibitory compound of the invention can be administered to a subject in vivo such that production of at least one cytokine that regulates development of a Thl or Th2 response is either stimulated or inhibited, respectively, in the subject, thereby influencing whether a Thl or a Th2 response predominates in the subject. In a preferred embodiment, the invention provides a method of stimulating a specific immune response to an antigen in a subject comprising: administering to the subject: (i) the antigen and (ii) a stimulatory form of an agent comprising a Lewis antigen, such that a specific immune response to the antigen is stimulated in the subject. In various embodiments, the agent comprises a Lewis v oligosaccharide or a derivative thereof, a Lewis x oligosaccharide or a derivative thereof, a Lewis a oligosaccharide or a derivative thereof, or a Lewis 0 oligosaccharide or a derivative thereof. The agent can be administered, for example, intranasally, orally, intravenously, intramuscularly, subcutaneously or mucosally. In another preferred embodiment, the invention provides a method of inhibiting an IgE response to an allergan in a subject comprising administering to the subject, in the presence ofthe allergan, an inhibitory form of an agent comprising a Lewis antigen, such that an IgE response to the allergan is inhibited in the subject. In various embodiments, the agent comprises a Lewis oligosaccharide or a derivative thereof, a Lewis oligosaccharide or a derivative thereof, a Lewis a oligosaccharide or a derivative thereof, or a Lewis 0 oligosaccharide or a derivative thereof. The agent can be administered, for example, intranasally, orally, intravenously, intramuscularly, subcutaneously or mucosally. In one embodiment ofthe method, the agent and the allergan are coadministered to the subject. Another aspect of the invention pertains to pharmaceutical compositions suitable for pharmaceutical administration. The pharmaceutical compositions ofthe invention typically comprise a stimulatory or inhibitory agent ofthe invention (e.g., a compound comprising a Lewis antigen) and a pharmaceutically acceptable carrier. In one embodiment, the composition is formulated to modulate responses by human immune cells. In another embodiment, the composition is formulated to modulate responses by macrophages. In yet another embodiment, the composition is formulated to modulate responses by T cells. In particular embodiments, the pharmaceutical formulation is suitable for administration by a specific route of delivery, such as intranasal delivery or oral delivery. Moreover, the pharmaceutical compositions of the invention can be packaged with instructions for using the pharmaceutical composition for a particular purpose, such as to modulate an immune response, for use as an adjuvant, to modulate an allergic response or to modulate an autoimmune disease. In a preferred embodiment, a pharmaceutical composition ofthe invention comprises a stimulatory form of an agent comprising a Lewis antigen and a pharmaceutical carrier, packaged with instructions for use of the pharmaceutical composition as an adjuvant for stimulating a specific immune response to an antigen. In another preferred embodiment, a pharmaceutical composition ofthe invention comprises an inhibitory form of an agent comprising a Lewis antigen and a pharmaceutical carrier, packaged with instructions for use ofthe pharmaceutical composition in the treatment of an allergy. The invention further provides pharmaceutical composition comprising a conjugate of a Lewis antigen, or derivative thereof, and a carrier molecule, for stimulating Th2-associated cytokine production, wherein the conjugate comprises optimized amounts ofthe Lewis antigen, or derivative thereof, for stimulation of cytokine production. For example, in a preferred embodiment, the Lewis antigen, or derivative thereof comprises at least 10 % of the conjugate by weight, more preferably at least 15% ofthe conjugate by weight, even more preferably at least 20% ofthe conjugate by weight and even more preferably at least 25% ofthe conjugate by weight. Still another aspect ofthe invention pertains to methods for stimulating production of a Th2-associated cytokine by a cell in vitro. The methods involve contacting a cell in vitro with a stimulatory form of an agent comprising a Lewis antigen such that production of a Th2-associated cytokine by the cell is stimulated. Preferably, the cell is selected from the group consisting of a T cell, a macrophage and a non-T, non-B spleen cell. Brief Description of the Drawings Figure 1 A is a bar graph depicting the proliferation of splenocytes from S. mansoni infected mice when stimulated with either media alone, Con A, LPS. anti-IgM, SEA or LNFP III conjugated to HSA. Figure 1 B is a graph depicting the proliferation of splenocytes from S. mansoni infected mice when stimulated with increasing amounts of either Lewis 3 antigen, Lewis x antigen, sialyl-Lewis x antigen or sialyl-Lewis a antigen, each conjugated to polyacrylamide. Figure IC is a bar graph depicting the proliferation of splenocytes from uninfected mice when stimulated with either media alone, Con A, LPS. anti-IgM, SEA or LNFP III conjugated to HSA. Figure ID is a graph depicting the proliferation of splenocytes from uninfected mice when stimulated with increasing amounts of either Lewis 3 antigen, Lewis x antigen, sialyl-Lewis x antigen or sialyl-Lewis a antigen, each conjugated to polyacrylamide. Figure 2A is a bar graph depicting the production of IL-IO by splenocytes from S. mansoni infected mice when stimulated with either media alone, Con A, LPS. anti- IgM, SEA or LNFP III conjugated to HSA. Figure 2B is a graph depicting the production of IL-10 by splenocytes from S. mansoni infected mice when stimulated with increasing amounts of either Lewis 3 antigen, Lewis x antigen, sialyl-Lewis x antigen or sialyl-Lewis 3 antigen, each conjugated to polyacrylamide. Figure 2C is a bar graph depicting the production of IL-10 by splenocytes from uninfected mice when stimulated with either media alone, Con A, LPS. anti-IgM, SEA or LNFP III conjugated to HSA. Figure 2D is a graph depicting the production of IL-10 by splenocytes from uninfected mice when stimulated with increasing amounts of either Lewis 3 antigen, Lewis x antigen, sialyl-Lewis x antigen or sialyl-Lewis a antigen, each conjugated to polyacrylamide. Figure 3 A is a bar graph depicting the production of IL-4 by splenocytes from S. mansoni infected mice when stimulated with either media alone, Con A, LPS. anti-IgM, SEA or LNFP III conjugated to HSA. Figure 3B is a graph depicting the production of IL-4 by splenocytes from S. mansoni infected mice when stimulated with increasing amounts of either Lewis 3 antigen, Lewis x antigen, sialyl-Lewis x antigen or sialyl-Lewis 3 antigen, each conjugated to polyacrylamide. Figure 3C is a bar graph depicting the production of IL-4 by splenocytes from uninfected mice when stimulated with either media alone, Con A, LPS. anti-IgM, SEA or LNFP III conjugated to HSA. Figure 3D is a graph depicting the production of IL-4 by splenocytes from uninfected mice when stimulated with increasing amounts of either Lewis 3 antigen, Lewis x antigen, sialyl-Lewis x antigen or sialyl-Lewis 3 antigen, each conjugated to polyacrylamide. Figure 4A is a bar graph depicting total serum IgE titers in mice administered intranasally either saline, HSA alone, HSA-LNFPIII conjugate, HSA-LNT conjugate or HSA together with free LNFPIII. Figure 4B is a bar graph depicting HSA-specific serum IgE titers in mice administered intranasally either saline, HSA alone, HSA-LNFPIII conjugate, HSA-LNT conjugate or HSA together with free LNFPIII. Figure 4C is a bar graph depicting Lewis x -specific serum IgE titers in mice administered intranasally either saline, HSA alone, HSA-LNFPIII conjugate, HSA-LNT conjugate or HSA together with free LNFPIII. Figure 5A is a bar graph depicting total serum IgE titers in mice administered intranasally either saline, PLA2 alone, PLA together with free LNFPIII or PLA 2 together with free LNT. Figure 5B is a bar graph depicting PLA2-specific serum IgE titers in mice administered intranasally either saline, PLA 2 alone, PLA 2 together with free LNFPIII or PL A? together with free LNT. Figure 6A is a bar graph depicting total serum IgE titers in mice administered intranasally either saline, SEA alone, SEA together with free LNFPIII or SEA together with free LNT. Figure 6B is a bar graph depicting SEA-specific serum IgE titers in mice administered intranasally either saline, SEA alone, SEA together with free LNFPIII or SEA together with free LNT. Figure 7A is a bar graph depicting titers of various isotypes of antibodies in sera of mice immunized with HSA-LNFPIII, as determined by ELISA using HSA-LNFPIII as the antigen bound to the ELISA plate. The results shown are for sera diluted 1 :400. Figure 7B is a bar graph depicting titers of various isotypes of antibodies in sera of mice immunized with HSA-LNFPIII, as determined by ELISA using HSA-LNT as the antigen bound to the ELISA plate. The results shown are for sera diluted 1 :400. Figure 7C is a bar graph depicting titers of various isotypes of antibodies in sera of mice immunized with HSA-LNFPIII, as determined by ELISA using HSA as the antigen bound to the ELISA plate. The results shown are for sera diluted 1 :400. Figure 8A is a bar graph depicting total serum IgE titers in mice administered intranasally either saline, HSA alone (10 μg) or HSA-LNFPIII conjugate (0.01 μg, 0.1 μg, 1 μg or 10 μg). Figure 8B is a bar graph depicting HSA-specific serum IgE titers in mice administered intranasally either saline, HSA alone (10 μg) or HSA-LNFPIII conjugate (0.01 μg, 0.1 μg, 1 μg or 10 μg). Figure 8C is a bar graph depicting HSA-specific serum IgM and IgG titers in mice administered intranasally either saline, HSA alone (10 μg) or HSA-LNFPIII conjugate (0.01 μg, 0.1 μg, l μg or lO μg). Figure 9A is a bar graph depicting the amount of IL-4 produced by nasal lymphocytes obtained from mice immunized in vivo with either saline, HSA alone or HSA-LNFPIII conjugate (1 μg or 10 μg). Figure 9B is a bar graph depicting the amount of IL-5 produced by nasal lymphocytes obtained from mice immunized in vivo with either saline, HSA alone or HSA-LNFPIII conjugate (1 μg or 10 μg). Figure 9C is a bar graph depicting the amount of IL-10 produced by nasal lymphocytes obtained from mice immunized in vivo with either saline, HSA alone or HSA-LNFPIII conjugate (1 μg or 10 μg). Figure 9D is a bar graph depicting the amount of IFN-γ produced by nasal lymphocytes obtained from mice immunized in vivo with either saline, HSA alone or HSA-LNFPIII conjugate (1 μg or 10 μg). Detailed Description of the Invention This invention provides immunomodulatory methods in which a cell (e.g., a human immune cell, a macrophage or a T cell) is contacted with an agent which modulates production by the cell of one or more cytokines that regulate Thl or Th2 responses. The invention is based, at least in part, on the discovery that when human immune cells, macrophages or T cells are stimulated with a multivalent, crosslinked form of a Lewis antigen, the cells produce one or more cytokines (such as IL- 10 and/or IL-4) that promote the development of a Th2 response and inhibit the development of a Thl response. Human immune cells that exhibit this responsiveness include T cells from a pollen allergic individual and peripheral blood mononuclear cells from individuals with colon or lung carcinomas or B lymphoma. Moreover, it has now been discovered that human immune cells preferentially respond to compounds comprising a Lewisy oligosaccharides. Still further, it has now been discovered that Lewis antigens conjugated to a carrier at a ligand density such that the sugars represent approximately 20-24% ofthe conjugate by weight are especially effective at stimulating production of cytokines that promote the development of a Th2 response (e.g., IL-10 and IL-4), an in particular can stimulate IL-4 production by splenocytes of uninfected subjects. A preferred carrier for such stimulatory conjugates is polyacrylamide. In contrast to these stimulatory methods, contact ofthe cells with a monovaient, non-crosslinked form of the Lewis antigen inhibits the production of cytokines that promote Th2 responses and downregulate Thl responses that normally are produced when the cells encounter a stimulatory form of a Lewis antigen. Thus, the methods of the invention allow for cytokine production either to be stimulated or inhibited, depending on whether a stimulatory agent or an inhibitory agent is used. Accordingly, the immunomodulatory methods ofthe invention allow for an immune response to be directed to either a Thl or a Th2 response. The ability to influence the development of either a Thl or a Th2 response using the immunomodulatory methods ofthe invention is applicable to the treatment of a wide variety of disorders, including cancer, infectious diseases (e.g., HIV and tuberculosis), allergies and autoimmune diseases. In order that the present invention may be more readily understood, certain terms are first defined. Standard abbreviations for sugars are used herein. As used herein, the term "Lewis antigen" is intended to include carbohydrates having as a core sequence either the lacto type I structure {Gal(βl-3)GlcNac} or the lacto type II structure {Gal(βl-4)GlcNac}, substituted with one or more fucosyl residues. The Lewis antigen may comprise a single substituted core sequence or a repetitive series of substituted core sequences. Moreover, the core sequence may be present within a larger sugar. Accordingly, a Lewis antigen-containing oligosaccharide can be, for example, a trisaccharide, a tetrasaccharide, a pentasaccharide, and so on. Types of Lewis antigens include Lewis x , Lewisy, Lewis 3 and Lewis 0 oligosaccharides and derivatives thereof. Synthetic structural homologues of these carbohydrates that retain the immunomodulatory capacity described herein are also intended to be encompassed by the term "Lewis antigen". As used herein, the term "Lewis x oligosaccharide" refers to a lacto type II carbohydrate comprising the structure: {Gal(βl-4)[Fuc(αl-3)]GlcNac}. As used herein, the term "Lewisy oligosaccharide" refers to a lacto type II carbohydrate comprising the structure: {Fuc(αl-2)Gal(βl-4)[Fuc(αl-3)]GlcNac}. As used herein, the term "Lewis 3 oligosaccharide" refers to a lacto type I carbohydrate comprising the structure: {Gal(βl-3)[Fuc(αl-4)]GlcNac}. As used herein, the term "Lewis 0 oligosaccharide" refers to a lacto type I carbohydrate comprising the structure: {Fuc(αl-2)Gal(βl-3)[Fuc(αl-4)]GlcNac}. As used herein, a "derivative" of a Lewis oligosaccharide refers to a Lewis oligosaccharide having one or more additional substituent groups. Examples of derivatives include terminally sialylated forms of Lewis oligosaccharides (e.g., sialyl- Lewis x , sialyl-Lewisy, sialyl-Lewis 3 , sialyl-Lewis 0 ), sulfated forms of Lewis oligosaccharides and sulfo-sialylated forms of Lewis oligosaccharides. As used herein, the term "human immune cell" is intended to include cells ofthe human immune cell which are capable of producing cytokines that regulate the development of a Thl or Th2 response. Examples of human immune cells include human T cells, human macrophages and human B cells. As used herein, the term "macrophage" is intended to include all cells within the macrophage lineage, including monocytes, circulating macrophages, tissue macrophages, activated macrophages, and the like, from a mammal (e.g., human or mouse). As used herein, the term "T cell" (i.e., T lymphocyte) is intended to include all cells within the T cell lineage, including thymocytes, immature T cells, mature T cells and the like, from a mammal (e.g., human or mouse). As used herein, a "T helper type 2 response" (Th2 response) refers to a response by CD4 + T cells that is characterized by the production of one or more cytokines selected from IL-4, IL-5, IL-6 and IL-10, and that is associated with efficient B cell "help" provided by the Th2 cells (e.g., enhanced IgGl and/or IgE production). As used herein, a "T helper type 1 response" (Thl response) refers to a response by CD4 + T cells that is characterized by the production of one or more cytokines selected from IL-2, IFN-g and TNF-β, and that is associated with delayed type hypersensitivity responses. As used herein, the term "a cytokine that regulates development of a Thl or Th2 response" is intended to include cytokines (produced by Thl or Th2 cells or other cell types), that have a positive or negative effect on the initiation and/or progression of a Thl or Th2 response, and especially those cytokines that have reciprocal effects on the development ofthe Thl vs. Th2 subpopulations, in particular, cytokines that promote the development of a Th2 response and downregulate the development of a Thl response. Preferred cytokines that are produced by the methods ofthe invention are IL- 10, IL-4 and prostaglandin E 2 (PGE 2 ). The most preferred cytokine produced by the methods ofthe invention is IL-10. As used herein, the term "development of a Thl or Th2 response" is intended to include initiation of either a Thl or Th2 response (e.g., commitment of T helper precursors to either the Thl or Th2 lineage) and progression of either a Thl or Th2 response (e.g. , further differentiation of cells to either the Thl or Th2 phenotype and/or continued function of Thl or Th2 cells during an ongoing immune response). Thus, a cytokine(s) produced in accordance with the methods ofthe invention may have an effect on the initiation of a Thl or Th2 response, the progression of a Thl or Th2 response, or both. As used herein, the term "Th2-associated cytokine" is intended to refer to a cytokine that is produced preferentially or exclusively by Th2 cells rather than by Thl cells. Examples of Th2-associated cytokines include IL-10, IL-4, IL-5, IL-6 and IL-13. As used herein, the term "non-T, non-B spleen cells" refers to cells isolated from total splenocytes that have been depleted of T cells and B cells. T cells typically are depleted by removal from the total splenocytes of cells bearing T cell-specific surface markers (e.g., removal of Thy + or CD5 + cells). Similarly, B cells typically are depleted by removal from the total splenocytes of cells bearing B cell-specific surface markers (e.g., removal of B220 + cells). As used herein, the various forms of the term "modulation" are intended to include stimulation (e.g. , increasing or upregulating a particular response or activity) and inhibition (e.g., decreasing or downregulating a particular response or activity). As used herein, the term "contacting" (i.e., contacting an agent with a cell) is intended to include incubating the agent and the cell together in vitro (e.g., adding the agent to cells in culture) and administering the agent to a subject such that the agent and cells ofthe subject are contacted in vivo. Various aspects ofthe invention are described in further detail in the following subsections. I. Immunomodulatory Agents In the immunomodulatory methods of the invention, a cell (e.g., a human immune cell, macrophage or T cell) is contacted with an agent that modulates interaction of a compound comprising a Lewis antigen with the cell such that production by the cell of at least one cytokine that regulates development of a Thl or Th2 response is modulated. Preferably, the agent itself comprises a Lewis antigen, as described in further detail below. In one embodiment, the agent is a "stimulatory agent", which stimulates production by the cell of at least one cytokine that regulates development of a Thl or Th2 response. In another embodiment, the agent is an "inhibitory agent", which inhibits production by the cell of at least one cytokine that regulates development of a Thl or Th2 response (i.e., the inhibitory agent can block the production of cytokines that normally occurs when the cell encounters a stimulatory form of a Lewis antigen). A. Stimulatory Agents The stimulatory agents ofthe invention stimulate production by cells of at least one cytokine that regulates development of a Thl or Th2 response. In a preferred embodiment, the stimulatory agent is a stimulatory form of a compound comprising a Lewis antigen. A "stimulatory form of a compound comprising a Lewis antigen" typically is one in which the carbohydrate structure is present in a multivalent, crosslinked form. In a preferred embodiment, the stimulatory form of a compound comprising a Lewis antigen is a conjugate of a carrier molecule and multiple carbohydrate molecules expressing a Lewis antigen. For example, carbohydrate molecules can be conjugated to a protein carrier, such as a conjugate of human serum albumin (HSA) and Lewisy oligosaccharides (referred to herein as HSA-Ley). When a sugar-carrier protein conjugate is to be administered to a subject, the carrier protein should be selected such that an immunological reaction to the carrier protein is not stimulated in the subject (e.g. , a human carrier protein should be used with a human subject, etc.). Alternative to a carrier protein, multiple Lewis antigens can be conjugated to other carrier molecules, such as a solid support, such as beads (e.g., polyacrylamide, agarose, sepharose, polystyrene and the like) or a plate. The degree of stimulatory ability ofthe conjugate is influenced by the density of sugars conjugated to the carrier (see Example 4). Preferably, the sugar molecules comprise at least 10% ofthe conjugate by weight, more preferably at least 15% ofthe conjugate by weight, even more preferably at least 20% ofthe conjugate by weight and even more preferably at least 25% of the conjugate by weight. In certain embodiments, the sugar molecules comprise about 10-25 % ofthe conjugate by weight, about 15-25% ofthe conjugate by weight or about 20-25% ofthe conjugate by weight. In a preferred embodiment, the stimulatory form of a compound comprising a Lewis antigen is a conjugate of multiple carbohydrate molecules expressing a Lewis antigen and the carrier polyacrylamide. More preferably, the polyacrylamide conjugates comprise 25 to 30 (or more) sugars/conjugate, wherein the average molecular weight ofthe conjugate is approximately 30 kD. The Lewis antigens present in the conjugate can be, for example, Lewisy, Lewis x , Lewis 3 or Lewis 0 oligosaccharides, or derivatives thereof. In certain embodiments for stimulation of human cells, the stimulatory agent preferably comprises Lewisy oligosaccharides or derivatives thereof. Within the stimulatory agent, the Lewis antigen can be present within a larger carbohydrate structure. For example, the carbohydrate portion ofthe stimulatory agent can be lacto-N-fucopentaose III (LNFP- III), which has the structure: {Gal(βl-4)[Fuc(αl-3)]GlcNac(βl-3)Gal(βl-4)GIc} and comprises the Lewis x oligosaccharide, or lacto-vV-difucohexose I (LND), which has the structure: {Fuc(αl-2)Gal(βl-3)[Fuc(αl-4)]GlcNac(βl-3)Gal(βl-4)Glc} and comprises the Lewis 0 oligosaccharide. Other related carbohydrates comprising Lewis antigens that are suitable for use in a stimulatory agent ofthe invention will be apparent to those skilled in the art. In addition to conjugates comprising Lewis antigen-containing sugars described above, another form of a stimulatory agent comprising a Lewis antigen is an isolated protein that naturally expresses Lewis antigens in a form suitable for stimulatory activity. One example of such a protein is schistosome egg antigen (SEA), which expresses the Lewis x oligosaccharide. Other proteins that have been reported to express Lewis antigens include tumor-associated antigens (see e.g., Pauli, B. U., et al. (1992) Trends in Glycoscience and Glycotechnology 4:405-414; Hakomori, S-I. (1989) Adv. Cancer Res. 52:257-331) and HIV gpl20 (Adachi, M., et al. (1988)J. Exp. Med. 167:323-331). Stimulatory agents for use in the methods ofthe invention can be purchased commercially or can be purified or synthesized by standard methods. Conjugates of Lewis antigen-containing sugars and a carrier protein (e.g., HSA) are available from Accurate Chemicals, Westbury, NY. Conjugates of Lewis antigen-containing sugars and polyacrylamide are available from GlycoTech. Rockville, MD. Schistosome egg antigen (SEA) can be purified from Schistosoma mansoni eggs as described in Harn, D.H., et al. (1984) J. Exp. Med. 159: 1371-1387. Lewis antigen-containing sugars, or derivatives thereof, can be conjugated to a carrier protein or solid support (e.g., beads or a plate) by standard methods, for example using a chemical cross-linking agent. A wide variety of bifunctional or polyfunctional cross-linking reagents, both homo- and hetero functional, are known in the art and are commercially available (e.g., Pierce Chemical Co., Rockford, IL). The ability of a stimulatory agent ofthe invention to stimulate production by immune cells of at least one cytokine that regulates a Thl or Th2 response can be evaluated using an in vitro culture system such as that described in the Examples. Cells (e.g., peripheral blood mononuclear cells) are cultured in the presence of the stimulatory agent to be evaluated (e.g., at a concentration of 100 μM for sugar conjugates) in a medium suitable for culture of the chosen cells. After a period of time (e.g., 24-72 hours), production of a cytokine that regulates development of a Thl or Th2 response is assessed by determining the level ofthe cytokine in the culture supernatant. Preferably, the cytokine assayed is IL-10. Additionally or alternatively, IL-4 and/or PGE 2 levels can be assessed. Cytokine levels in the culture supernatant can be measured by standard methods, such as by an enzyme linked immunosorbent assay (ELISA) utilizing a monoclonal antibody that specifically binds the cytokine. An ELISA for measuring IL- 10 levels is described further in Kullberg, M.C., et al. (1992) J. Immunol. 148:3264- 3270. An ELISA kit for measuring PGE 2 levels is commercially available from Advanced Magnetics, Cambridge, MA. The ability of a stimulatory agent to stimulate cytokine production is evidenced by a higher level of cytokine (e.g., IL-10) in the supernatants of cells cultured in the presence ofthe stimulatory agent compared to the level of cytokine in the supernatant of cells cultured on the absence ofthe stimulatory agent. B. Inhibitory Aeents The inhibitory agents ofthe invention inhibit production by cells of at least one cytokine that regulates development of a Thl or Th2 response. More specifically, cytokine production by a cell that normally occurs when the cell encounters a stimulatory form of a Lewis antigen can be inhibited by contacting the cell with an inhibitory agent ofthe invention (i.e., the inhibitory agents of the invention act as blocking agents to inhibit cytokine production that normally would result from interaction ofthe cell with a stimulatory form of a Lewis antigen). In a preferred embodiment, the inhibitory agent is an inhibitory form of a compound comprising a Lewis antigen. A "inhibitory form of a compound comprising a Lewis antigen" typically is one in which the carbohydrate structure is present in a monovaient, non- crosslinked form. Preferred inhibitory agents are soluble, "free" sugars comprising a Lewis antigen. The Lewis antigen expressed by the inhibitory agent can be, for example, a Lewisy, Lewis x , Lewis 3 or Lewis 0 oligosaccharide (a single substituted core sequence or a repetitive series of substituted core sequences) or derivatives thereof. For inhibition of human cells, the inhibitory agent preferably comprises a Lewisy oligosaccharide or a derivative thereof. Within the inhibitory agent, the Lewis antigen can be present within a larger carbohydrate structure. For example, the carbohydrate portion ofthe inhibitory agent can be lacto-N-fucopentaose III (LNFP-III), which has the structure: {Gal(βl-4)[Fuc(αl-3)]GlcNac(βl-3)Gal(βl-4)Glc} and comprises the Lewis x oligosaccharide, or lacto-N-difucohexose I (LND), which has the structure: {Fuc(αl- 2)Gal(βl-3)[Fuc(αl-4)]GlcNac(βl-3)Gal(βl-4)Glc} and comprises the Lewis 0 oligosaccharide. Other related carbohydrates comprising Lewis antigens that are suitable for use in an inhibitory agent ofthe invention will be apparent to those skilled in the art. Soluble, free sugars comprising a Lewis antigen for use as inhibitory agents can be purchased commercially or synthesized by standard methods (as described above). In addition to free sugars comprising Lewis antigens, another form of an inhibitory agent is an antibody to a Lewis antigen. Polyclonal antibodies, or more preferably monoclonal antibodies (mAbs), that specifically bind a Lewis antigen (e.g., a Lewisy, Lewis x , Lewis 3 or Lewis 0 oligosaccharide, or derivatives thereof) can be used as inhibitory agents. Monoclonal antibodies to Lewis antigens, or derivatives thereof, are known in the art (e.g., mAbs to Le x , Ley, sialyl-Le x or sialyl-Ley, from the Biomembrane Institute, Seattle, WA, as described in Martensson, S., et al. (1995) Hum. Pathol. 26:735-739; and mAbs to Le 3 or sialyl-Le 3 , as described in Kageshita, T., et al. ( 1995) Cancer Res. 55 : 1748- 1751 ) The ability of an inhibitory agent ofthe invention to inhibit production by immune cells of at least one cytokine that regulates a Thl or Th2 response that normally occurs when the immune cell encounters a stimulatory form of a Lewis antigen can be evaluated using an in vitro culture system such as that described in the Examples. Cells (e.g., peripheral blood mononuclear cells) are cultured in the presence of both an inhibitory agent to be evaluated and a stimulatory agent as described in the preceding section (e.g., a sugar conjugate at a concentration of 100 μM) in a medium suitable for culture ofthe chosen cells. After a period of time (e.g., 24-72 hours), production of a cytokine that regulates development of a Thl or Th2 response (e.g., IL-10 or IL-4) is assessed by determining the level ofthe cytokine in the culture supernatant as described in the preceding section. The ability of an inhibitory agent to inhibit cytokine production is evidenced by a lower level of cytokine in the supernatants of cells cultured in the presence of both the inhibitory agent and the stimulatory agent compared to the level of cytokine in the supernatant of cells cultured only in the presence ofthe stimulatory agent. II. Pharmaceutical Compositions Another aspect ofthe invention pertains to pharmaceutical compositions ofthe stimulatory or inhibitory agents ofthe invention. The pharmaceutical compositions of the invention typically comprise a stimulatory or inhibitory agent ofthe invention and a pharmaceutically acceptable carrier. As used herein "pharmaceutically acceptable carrier" includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absoφtion delaying agents, and the like that are physiologically compatible. The type of carrier can be selected based upon the intended route of administration. In various embodiments, the carrier is suitable for intravenous, intraperitoneal, subcutaneous, intramuscular, transdermal or oral administration. In a preferred embodiment, the composition is formulated such that it is suitable for intravenous administration. Pharmaceutically acceptable carriers include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. The use of such media and agents for pharmaceutically active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with the active compound, use thereof in the pharmaceutical compositions ofthe invention is contemplated. Supplementary active compounds can also be incorporated into the compositions. Therapeutic compositions typically must be sterile and stable under the conditions of manufacture and storage. The composition can be formulated as a solution, microemulsion, liposome, or other ordered structure suitable to high drug concentration. The carrier can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyetheylene glycol, and the like), and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance ofthe required particle size in the case of dispersion and by the use of surfactants. In many cases, it will be preferable to include isotonic agents, for example, sugars, polyalcohols such as manitol, sorbitol, or sodium chloride in the composition. Prolonged absoφtion ofthe injectable compositions can be brought about by including in the composition an agent which delays absoφtion, for example, monostearate salts and gelatin. Moreover, the modulators can be administered in a time release formulation, for example in a composition which includes a slow release polymer. The active compounds can be prepared with carriers that will protect the compound against rapid release, such as a controlled release formulation, including implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, polylactic acid and polylactic, polyglycolic copolymers (PLG). Many methods for the preparation of such formulations are patented or generally known to those skilled in the art. Sterile injectable solutions can be prepared by incoφorating the active compound in the required amount in an appropriate solvent with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incoφorating the active compound into a sterile vehicle which contains a basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and freeze-drying which yields a powder ofthe active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof. Depending on the route of administration, the agent may be coated in a material to protect it from the action of enzymes, acids and other natural conditions which may inactivate the agent. For example, the agent can be administered to a subject in an appropriate carrier or diluent co-administered with enzyme inhibitors or in an appropriate carrier such as liposomes. Pharmaceutically acceptable diluents include saline and aqueous buffer solutions. Enzyme inhibitors include pancreatic trypsin inhibitor, diisopropylfluorophosphate (DEP) and trasylol. Liposomes include water-in- oil-in-water emulsions as well as conventional liposomes (Strejan, et al, (1984) J. Neuroimmunol 7:27). Dispersions can also be prepared in glycerol, liquid polyethylene glycols, and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations may contain a preservative to prevent the growth of microorganisms. The active agent in the composition (i.e., a stimulatory or inhibitory agent ofthe invention) preferably is formulated in the composition in a therapeutically effective amount. A "therapeutically effective amount" refers to an amount effective, at dosages and for periods of time necessary, to achieve the desired therapeutic result, such as the development or progression of a Th2 or Thl response to thereby influence the therapeutic course of a particular disease state. A therapeutically effective amount of an active agent may vary according to factors such as the disease state, age, sex, and weight ofthe individual, and the ability ofthe agent to elicit a desired response in the individual. Dosage regimens may be adjusted to provide the optimum therapeutic response. A therapeutically effective amount is also one in which any toxic or detrimental effects ofthe agent are outweighed by the therapeutically beneficial effects. In another embodiment, the active agent is formulated in the composition in a prophylactically effective amount. A "prophylactically effective amount" refers to an amount effective, at dosages and for periods of time necessary, to achieve the desired prophylactic result, for example, influencing the development or progression of either a Th2 or Thl response for prophylactic puφoses. Typically, since a prophylactic dose is used in subjects prior to or at an earlier stage of disease, the prophylactically effective amount will be less than the therapeutically effective amount. A non-limiting range for a therapeutically or prophylactically effective amounts of a stimulatory or inhibitory agent ofthe invention is 0.01 nM-20 mM. It is to be noted that dosage values may vary with the severity ofthe condition to be alleviated. It is to be further understood that for any particular subject, specific dosage regimens should be adjusted over time according to the individual need and the professional judgment ofthe person administering or supervising the administration of the compositions, and that dosage ranges set forth herein are exemplary only and are not intended to limit the scope or practice ofthe claimed composition. The amount of active compound in the composition may vary according to factors such as the disease state, age, sex, and weight of the individual. Dosage regimens may be adjusted to provide the optimum therapeutic response. For example, a single bolus may be administered, several divided doses may be administered over time or the dose may be proportionally reduced or increased as indicated by the exigencies of the therapeutic situation. It is especially advantageous to formulate parenteral compositions in dosage unit form for ease of administration and uniformity of dosage. Dosage unit form as used herein refers to physically discrete units suited as unitary dosages for the mammalian subjects to be treated; each unit containing a predetermined quantity of active compound calculated to produce the desired therapeutic effect in association with the required pharmaceutical carrier. The specification for the dosage unit forms of the invention are dictated by and directly dependent on (a) the unique characteristics ofthe active compound and the particular therapeutic effect to be achieved, and (b) the limitations inherent in the art of compounding such an active compound for the treatment of sensitivity in individuals. A stimulatory or inhibitory agent ofthe invention can be formulated into a pharmaceutical composition wherein the agent is the only active compound therein. Alternatively, the pharmaceutical composition can contain additional active compounds. For example, two or more stimulatory or inhibitory agents may be used in combination. Moreover, a stimulatory or inhibitory agent ofthe invention can be combined with one or more other agents that have immunomodulatory properties. For example, a stimulatory or inhibitory agent may be combined with one or more cytokines or adjuvants. A pharmaceutical composition ofthe invention, comprising a stimulatory or inhibitory agent ofthe invention, can be administered to a subject to modulate immune responses (e.g., Th2 vs. Thl responses) in the subject. As used herein, the term "subject" is intended to include living organisms in which an immune response can be elicited, e.g., mammals. Examples of subjects include humans, dogs, cats, mice, rats, and transgenic species thereof. A pharmaceutical composition ofthe invention can be formulated to be suitable for a particular route of administration. For example, in various embodiments, a pharmaceutical composition ofthe invention can be suitable for injection, inhalation or insufflation (either through the mouth or the nose), or for intranasal, mucosal, oral, buccal, parenteral, rectal, intramuscular, intravenous, intraperitoneal, and subcutaneous delivery. In certain embodiments, a pharmaceutical composition ofthe invention can be packaged with instructions for using the pharmaceutical composition for a particular puφose, such as to modulate an immune response, for use as an adjuvant, to modulate an allergic response or to modulate an autoimmune disease. III. Modulation of Immune Responses The invention provides immunomodulatory methods that can be used to influence the development of a Thl or a Th2 response. In the methods ofthe invention, a cell is contacted with an agent that modulates interaction of a compound comprising a Lewis antigen with the cell such that production by the cell of at least one cytokine that regulates development of a Thl or Th2 response is modulated (i.e., stimulated or inhibited). The methods ofthe invention can be practiced either in vitro or in vivo. For practicing the method ofthe invention in vitro, cells can be obtained from a subject by standard methods and incubated (i.e., cultured) in vitro with a stimulatory or inhibitory agent ofthe invention to stimulate or inhibit, respectively, the production of at least one cytokine that regulates development of a Thl or Th2 response. For example, peripheral blood mononuclear cells (PBMCs) can be obtained from a subject and isolated by density gradient centrifugation, e.g., with Ficoll Hypaque. Specific cell populations can be depleted or enriched using standard methods. For example, monocytes/macrophages can be isolated by adherence on plastic. T cells or B cells can be enriched or depleted, for example, by positive and/or negative selection using antibodies to T cell or B cell surface markers, for example by incubating cells with a specific mouse monoclonal antibody (mAb), followed by isolation of cells that bind the mAb using anti-mouse-Ig coated magnetic beads. Monoclonal antibodies to cell surface markers are commercially available. When a stimulatory agent is used in vitro, resulting in stimulation ofthe production of at least one cytokine that regulates Thl or Th2 responses, the cytokine(s) can be recovered from the culture supematant for further use. For example, the culture supematant, or a purified fraction thereof, can be applied to T cells in culture to influence the development of Thl or Th2 cells in vitro. Alternatively, the culture supematant, or a purified fraction thereof, can be administered to a subject to influence the development of Thl vs. Th2 responses in the subject. Moreover, cells treated in vitro with either a stimulatory or inhibitory agent can be administered to a subject to influence the development of a Thl vs. Th2 response in the subject. For administration to a subject, it may be preferable to first remove residual agents in the culture from the cells before administering them to the subject. This can be done for example by a Ficoll/Hypaque gradient centrifugation ofthe cells. For practicing the methods ofthe invention in vivo, a stimulatory or inhibitory agent is administered to a subject in a pharmacologically acceptable carrier (as described in the previous section) in amounts sufficient to achieve the desired effect, such as to modulate production of at least one cytokine that regulates development of a Thl or Th2 response in the subject or to stimulate an antigen-specific immune response in the subject or to inhibit a disease or disorder (e.g., an allergy or an autoimmune disease) in the subject. Any route of administration suitable for achieving the desired immunomodulatory effect is contemplated by the invention. One preferred route of administration for the agent is intranasally. Another preferred route of administration is orally. Yet another preferred route of administration is intravenous. The stimulatory methods ofthe invention (i.e., methods that use a stimulatory agent) result in production of at least one cytokine (e.g., IL-10 or IL-4) which promotes development of a Th2 response and/or inhibits development of a Thl response. Alternatively, the inhibitory methods ofthe invention (i.e. , methods that use an inhibitory agent) inhibit the production of at least one cytokine (e.g., IL-10 or IL-4) which promotes development of a Th2 response and/or inhibits development of a Thl response. Thus, to apply a method ofthe invention to the treatment of a disease condition wherein a Thl response is beneficial, an immunomodulatory method is selected that promotes such a Thl response (while downregulating a Th2 response). Alternatively, to apply a method ofthe invention to the treatment of a disease condition wherein a Th2 response is beneficial, an immunomodulatory method is selected that promotes such a Th2 response (while downregulating a Thl response). Application of the methods ofthe invention to the treatment of disease conditions may result in cure of the condition, a decrease in the type or number of symptoms associated with the condition, either in the long term or short term (i.e., amelioration ofthe condition) or simply a transient beneficial effect to the subject. Numerous disease conditions associated with a predominant Thl or Th2-type response have been identified and could benefit from modulation ofthe type of response mounted in the individual suffering from the disease condition. Application ofthe immunomodulatory methods ofthe invention to such diseases is described in further detail below. A. Cancer The inhibitory methods ofthe invention can be used to inhibit the production of cytokines that upregulate Th2 responses and downregulate Thl responses in cancer patients, thereby promoting a Thl response in the patients to ameliorate the course ofthe disease. The expression of Th2 -promoting cytokines, in particular IL-10, has been reported to be elevated in cancer patients (see e.g., Yamamura, M., et al. (1993) J. Clin. Invest. 91:1005-1010; Pisa, P., et al. (1992) Proc. Natl. Acad. Sci. USA 89:7708-7712). Moreover, malignant cells have been reported to express tumor-associated antigens that comprise Lewis antigens (see e.g., Pauli, B. U., et al. (1992) Trends in Glycoscience and Glycotechnology 4:405-414; Hakomori, S-I. (1989) Adv. Cancer Res. 52:257-331 ; Martensson, S., et al. (1995) Hum. Pathol. 26:735-739; Kageshita, T., et al. (1995) Cancer Res. 55:1748-1751 ; Ohta, S., et al. (\995) Immunol. Letters 44:35-40). Still further, as demonstrated herein in Examples 2 and 3, peripheral blood mononuclear cells from patients with a variety of cancers (e.g., lung carcinoma, colon carcinoma or B lymphoma) respond to stimulation with Lewis antigen-protein carrier conjugates by producing IL-10. Thus, in the natural setting, stimulatory forms of Lewis antigens on tumor cells likely stimulate IL- 10 production in cancer patients, thereby shifting the immune response toward a Th2 response and away from a Thl response. This Th2 to Thl shift can be counteracted by treating a cancer patient with an inhibitory agent ofthe invention to inhibit IL-10 production in the patient and promote a Thl response. A preferred inhibitory agent for inhibiting IL- 10 production in human subjects comprises an inhibitory form of a Lewis oligosaccharide or derivative thereof (e.g., soluble, free Ley), although the particular Lewis antigen effective for inhibiting IL- 10 production in individual cancer patients may vary for different patients and/or tumors (e.g., as shown in Examples 2 and 3, cells from two patients with B lymphoma and one patient with colon carcinoma responded preferentially to Ley, whereas cells from one patient with B lymphoma responded preferentially to Le° and cells from one patient with lung carcinoma responded to Le x ). To determine which inhibitory agent is likely to be most effective for a particular cancer patient, it may be necessary first to determine which Lewis antigen is expressed on the tumor cells ofthe patient (e.g., by reacting a sample of tumor cells in vitro with a panel of mAbs that bind to different Lewis antigens) and/or which Lewis antigen the cells from the cancer patient preferentially respond to in vitro (e.g., by culturing PBMCs from the cancer patient in vitro with various stimulatory forms of Lewis antigens in an assay as described in the Examples). Based on these in vitro tests, an appropriate inhibitory agent can be selected that, when administered to the cancer patient, will block the stimulation of IL-10 production that results when cells ofthe cancer patient encounter Lewis antigens on tumor cells in vivo. B. Infectious Disease The inhibitory methods ofthe invention also can be used to inhibit the production of cytokines that upregulate Th2 responses and downregulate Thl responses in patients with infectious diseases, thereby promoting a Thl response in the patients to ameliorate the course ofthe disease. The expression of Th2 -promoting cytokines, in particular IL-10, has been reported to increase during a variety of infections, including HIV infection, tuberculosis, leishmaniasis, schistosomiasis, filarial nematode infection and intestinal nematode infection (see e.g. ; Shearer, G.M. and Clerici, M. (1992) Prog. Chem. Immunol. 54:21-43; Clerici, M and Shearer, G.M. (1993) Immunology Today 14: 107-1 1 1 ; Fauci, A.S. (1988) Science 239:617-623; Locksley, R. M. and Scott, P. (1992) Immunoparasitology Today LA58-A61 ; Pearce, E.J., et al. (1991) J Exp. Med. 173:159-166; Grzych, J-M., et al. (1991) J Immunol. 111:1322-1327; Kullberg, M.C., et al. (1992) J. Immunol. 148:3264-3270; Bancroft, A.J., et al. (1993) J. Immunol. 150:1395-1402; Pearlman, E., et al. (1993) Infect. Immun. 61:1105-11 12; Else, K.J., et al. ( 1994) J. Exp. Med. 179:347-351 ) and is associated with a Thl to Th2 shift. Infected cells and/or proteins from infectious agents have been reported to express Lewis antigens. For example, the Lewisy oligosaccharide has been reported to be expressed by HIV-infected cells (Adachi, M., et al. (1988) J. Exp. Med. 167:323-331). Schistosome egg antigen expresses the Lewis x oligosaccharide (Ko, A., et al. (1987) Proc. Natl. Acad. Sci. USA 87:4159-4163). Liver cells in chronic active hepatitis express the Lewisy oligosaccharide (Muguruma, M, et al. ( 1994) Anatomic Pathology 102: 176- 181). while Kupffer cells express sialyl oligomeric Lewis x (Okado. Y. and Tsuji, T. (1990) Lancet 33^:1302-1307). Thus, during the course of various natural infection, stimulatory forms of Lewis antigens on infected cells and/or expressed by proteins ofthe infectious agent likely stimulate IL-10 production in the infected subject, thereby shifting the immune response toward a Th2 response and away from a Thl response. This Th2 to Thl shift can be counteracted by treating the infected subject with an inhibitory agent ofthe invention to inhibit IL-10 production in the infected subject and promote a Thl response (similar to the approach described above for treating cancer patients). The inhibitory agent that is likely to be most effective for treatment of a particular infection can be determined by approaches similar to those described above for selecting inhibitory agents to treat cancer patient (for example, the type of Lewis antigen expressed by infected cells and/or proteins ofthe infectious agent can be determined and/or one can determine which Lewis antigen the cells from the subject preferentially respond to in vitro). C. Allergies: Allergies are mediated through IgE antibodies whose production is regulated by the activity of Th2 cells and the cytokines produced thereby. In allergic reactions, IL-4 is produced by Th2 cells, which further stimulates production of IgE antibodies and activation of cells that mediate allergic reactions, i.e., mast cells and basophils. IL-4 also plays an important role in eosinophil mediated inflammatory reactions. As demonstrated in Example 2, T cells from a patient allergic to pollen respond to stimulation with stimulatory forms of Lewis antigens by producing IL-10. Production of IL-10 in allergic patients may promote a Th2 response and downregulates a Thl response, thereby exacerbating the allergic condition. As demonstrated in Example 5, administration of an inhibitory agent ofthe invention downregulates IgE responses to a variety of antigens. Accordingly, an allergic subject can be treated with an inhibitory agent of the invention to downregulate allergan-specific IgE responses as a means to alleviate the allergic condition. While not intending to be limited by mechanism, it is thought that the inhibitory agents act in vivo to inhibit Th2-associated cytokine production (e.g., IL-10 production) in the subject and shift the immune response away from a Th2 response and toward a Thl response. Allergic reactions may be systemic or local in nature, depending on the route of entry ofthe allergen and the pattern of deposition of IgE on mast cells or basophils. Thus, for treatment of an allergic subject, an inhibitory agent ofthe invention can be administered either systemically or locally. Moreover, it may be beneficial to coadminister to the subject the allergen together with the inhibitory agent to inhibit (e.g., desensitize) the allergen-specific response. In a preferred embodiment, the invention provides a method of inhibiting an IgE response to an allergan in a subject comprising administering to the subject, in the presence ofthe allergan, an inhibitory form of an agent comprising a Lewis antigen, such that an IgE response to the allergan is inhibited in the subject. In various embodiments, the agent comprises a Lewisy oligosaccharide or a derivative thereof, a Lewis x oligosaccharide or a derivative thereof, a Lewis 3 oligosaccharide or a derivative thereof, or a Lewis 0 oligosaccharide or a derivative thereof. In certain embodiments, the agent and the allergan are coadministered to the subject. D. Autoimmune Diseases: The methods ofthe invention also can be used therapeutically for treating autoimmune diseases which are associated with a Thl - or Th2-type dysfunction. Many autoimmune disorders are the result of inappropriate activation of T cells that are reactive against self tissue and that promote the production of cytokines and autoantibodies involved in the pathology ofthe diseases. It has been shown that modulation of T helper-type responses can either have a beneficial or detrimental effect on an autoimmune disease. For example, in experimental allergic encephalomyelitis (EAE), stimulation of a Th2-type response by administration of IL-4 at the time of the induction ofthe disease diminishes the intensity ofthe autoimmune disease (Paul, W.E., et al. (1994) Cell 76:241-251). Furthermore, recovery ofthe animals from the disease has been shown to be associated with an increase in a Th2-type response as evidenced by an increase of Th2-specific cytokines (Koury, S. J., et al. (1992) J. Exp. Med. 176:1355-1364). Moreover, T cells that can suppress EAE secrete Th2-specific cytokines (Chen, C, et al. (1994) Immunity L 147-154). Since stimulation of a Th2-type response in EAE has a protective effect against the disease, stimulation of a Th2 response in subjects with multiple sclerosis (for which EAE is a model) may be beneficial therapeutically. Similarly, stimulation of a Th2-type response in type I diabetes in mice provides a protective effect against the disease. Indeed, treatment of NOD mice with IL-4 (which promotes a Th2 response) prevents or delays onset of type I diabetes that normally develops in these mice (Rapoport, M.J., et al. (1993) J. Exp. Med. 178:87-99). Thus, stimulation of a Th2 response in a subject suffering from or susceptible to diabetes may ameliorate the effects ofthe disease or inhibit the onset ofthe disease. Yet another autoimmune disease in which stimulation of a Th2-type response may be beneficial is rheumatoid arthritis (RA). Studies have shown that patients with rheumatoid arthritis have predominantly Thl cells in synovial tissue (Simon, A.K., et al, (1994) Proc. Natl Acad. Sci. USA 9 8562-8566). By stimulating a Th2 response in a subject with RA, the detrimental Thl response can be concomitantly downmodulated to thereby ameliorate the effects of the disease. To treat an autoimmune disease in which a Th2-type response is beneficial to the course ofthe disease in the subject, a stimulatory agent ofthe invention can be administered to the subject in amounts sufficient to stimulate a Th2-type response. The stimulatory agent can be used alone, or in combination with one or more additional agents that promote Th2 responses (e.g., Th2-promoting cytokines, such as IL-4 or IL- 10). Depending on the disease, the stimulatory agent may be administered either systemically or locally. For example in the case of rheumatoid arthritis, the agent may be administered directly into the joints. For systemic treatment, the stimulatory agent preferably is administered intravenously. Altemative to direct administration ofthe stimulatory agent to the subject, autoimmune diseases may be treated by an ex vivo approach. In this case, immune cells (e.g., T cells, macrophages and/or B cells) are obtained from a subject having an autoimmune disease, cultured in vitro with a stimulatory agent ofthe invention to stimulate production by the cells of one or more cytokines that promote a Th2 response (e.g., IL-10), followed by readministration ofthe cells to the subject. In contrast to the autoimmune diseases described above in which a Th2 response is desirable, other autoimmune diseases may be ameliorated by a Thl -type response. Such diseases can be treated using an inhibitory agent ofthe invention (as described above for cancer and infectious diseases). The treatment may be further enhanced by administrating a Thl -promoting cytokine (e.g., IFN-γ) to the subject in amounts sufficient to further stimulate a Thl -type response. The efficacy of agents for treating autoimmune diseases can be tested in the above described animal models of human diseases (e.g., EAE as a model of multiple sclerosis and the NOD mice as a model for diabetes) or other well characterized animal models of human autoimmune diseases. Such animal models include the mrl/lpr/lpr mouse as a model for lupus erythematosus, murine collagen-induced arthritis as a model for rheumatoid arthritis, and murine experimental myasthenia gravis (see Paul ed., Fundamental Immunology, Raven Press, New York, 1989, pp. 840-856). A modulatory (i.e., stimulatory or inhibitory) agent ofthe invention is administered to test animals and the course ofthe disease in the test animals is then monitored by the standard methods for the particular model being used. Effectiveness ofthe modulatory agent is evidenced by amelioration ofthe disease condition in animals treated with the agent as compared to untreated animals (or animals treated with a control agent). Non-limiting examples of autoimmune diseases and disorders having an autoimmune component that may be treated according to the invention include diabetes mellitus, arthritis (including rheumatoid arthritis, juvenile rheumatoid arthritis, osteoarthritis, psoriatic arthritis), multiple sclerosis, myasthenia gravis, systemic lupus erythematosis, autoimmune thyroiditis, dermatitis (including atopic dermatitis and eczematous dermatitis), psoriasis, Sjogren's Syndrome, including keratoconjunctivitis sicca secondary to Sjogren's Syndrome, alopecia areata, allergic responses due to arthropod bite reactions, Crohn's disease, aphthous ulcer, iritis, conjunctivitis, keratoconjunctivitis, ulcerative colitis, asthma, allergic asthma, cutaneous lupus erythematosus, scleroderma, vaginitis, proctitis, drug eruptions, leprosy reversal reactions, erythema nodosum leprosum, autoimmune uveitis, allergic encephalomyelitis, acute necrotizing hemorrhagic encephalopathy, idiopathic bilateral progressive sensorineural hearing loss, aplastic anemia, pure red cell anemia, idiopathic thrombocytopenia, polychondritis, Wegener's granuiomatosis, chronic active hepatitis, Stevens- Johnson syndrome, idiopathic sprue, lichen planus, Crohn's disease, Graves ophthalmopathy, sarcoidosis, primary biliary cirrhosis, uveitis posterior, and interstitial lung fibrosis. E. Inflammatory Bowel Disease in Infants The methods and compositions ofthe invention also can be used to downregulate inflammatory immune responses in the bowel in newborn infants. The largest biological source for Lewis-antigen containing oligosaccharides is human breast milk and breast fed babies have a lower incidence of diarrhea and colitis/inflammatory bowel disease. Commercially available formula was tested for the presence of Lewis antigen-containing sugars by ELISA and was found not to contain detectable amounts of these sugars, nor did the ingredients list these sugars as additives. Nonfat dry milk was listed as an additive to the formula but when non-fat dry milk was tested for the presence of Lewis antigen-containing sugars by ELISA, again none were detected. Thus, Lewis antigen- containing compounds as described herein can be added to commercial baby formulas and administered to infants orally to inhibit diarrhea and colitis/inflammatory bowel disease. Accordingly, the invention provides an infant formula comprising one or more Lewis antigen-containing compounds as an additive. In addition to the foregoing disease situations, the immunomodulatory methods ofthe invention also are useful for other puφoses. For example, the stimulatory methods of the invention (i.e., methods using a stimulatory agent) can be used to stimulate production of Th2 -promoting cytokines (such as IL-10 or IL-4) in vitro for commercial production of these cytokines (e.g., cells can be cultured with a stimulatory agent in vitro to stimulate IL-10 or IL-4 production and the IL-10 or IL-4 can be recovered from the culture supematant, further purified if necessary, and packaged for commercial use). Furthermore, the immunomodulatory methods ofthe invention can be applied to vaccinations to promote either a Thl or a Th2 response to an antigen of interest in a subject. That is, the agents ofthe invention can serve as adjuvants to direct an immune response to a vaccine either to a Thl response or a Th2 response. For example, to stimulate an antibody response to an antigen of interest (i.e., for vaccination puφoses), the antigen and a stimulatory agent ofthe invention can be coadministered to a subject to promote a Th2 response to the antigen in the subject, since Th2 responses provide efficient B cell help and promote IgGl production. As demonstrated in Example 6, the stimulatory agents of the invention are effective at stimulating antigen-specific IgG responses in vivo (i.e., the stimulatory agents are effective as adjuvants for stimulating a specific immune response to an antigen of interest in a naive subject). Alternatively, to promote a cellular immune response to an antigen of interest, the antigen and an inhibitory agent ofthe invention can be coadministered to a subject to promote a Thl response to the antigen in a subject, since Thl responses favor the development of cell-mediated immune responses (e.g., delayed hypersensitivity responses). The antigen of interest and the modulatory agent can be formulated together into a single pharmaceutical composition or in separate compositions. In a preferred embodiment, the antigen of interest and the modulatory agent are administered simultaneously to the subject. Alternatively, in certain situations it may be desirable to administer the antigen first and then the modulatory agent or vice versa (for example, in the case of an antigen that naturally evokes a Thl response, it may be beneficial to first administer the antigen alone to stimulate a Thl response and then administer a stimulatory agent, alone or together with a boost of antigen, to shift the immune response to a Th2 response). This invention is further illustrated by the following examples which should not be construed as limiting. The contents of all references, patents and published patent applications cited throughout this application are hereby incoφorated by reference. EXAMPLE 1: In this example, the ability of macrophages to produce IL-10 upon stimulation with various oligosaccharide conjugates was examined. Granuloma macrophages were prepared from C57BL/6 mice as described in Flores Villanueva, P.O., et al. (1994) J. Immunol. 153:5190-5199 and Flores Villanueva, P.O., et al. (1994) J. Immunol. 152: 1847-1855. Two million cells in 1 ml of DMEM, 10 % FCS were incubated with either no stimulant (i.e., medium alone; a negative control), lipopolysaccharide (LPS; at 20 μg/ml; a positive control), schistosome egg antigen (SEA; at 10 μg/ml), various sugars conjugated to human serum albumin (at 100 μg/ml) or human serum albumin alone (HSA; at 100 μg/ml; a negative control). The sugar conjugates tested were lacto- N-fucopentaose III (LNFP-III), lacto-N-neotetraose (LNT) and Lewisy (Ley). The oligosaccharide conjugates were obtained from Accurate Chemicals, Westbury, NY. At various time points (24, 48 and 72 hours), the level of IL-10 in the supematant was determined by two-site ELISA as described by ullberg, et al. (J. Immunol. (1982) 148:3264-3270). Briefly, polystyrene microtiter plates (Costar) were coated with IL-10-specific monoclonal antibodies (clone SXC-1 ; DNAX Coφ.). Culture supernatants were incubated on the antibody-coated plates and then probed with biotinylated antibody. Serial dilutions of recombinant mouse IL-10 (PharMingen) were assayed simultaneously to construct a standard curve for relative IL-10 concentration. To detect the biotinylated antibody bound to IL-10, avidin-peroxidase conjugate (Sigma Chemical Coφ., St. Louis, MO) was diluted in phosphate buffered saline (PBSV10 % fetal calf serum and added to the wells for 30 minutes at room temperature. The plates were washed with PBS/0.5 % Tween 20 (Fisher), and then tetramethylbenzidine substrate (Kirkegaard & Perry Laboratories) was added; the reaction was stopped with 0.4 M phosphoric acid and read at 450 nm in a UvMax Reader (Molecular Devices). The results are shown below in Table I. Table I: IL-10 Secretion by Granuloma Macrophages IL- 10 LEVEL (PG/ML) STIMULANTS 24 HR 48 HR 72 HR Medium 898 1510 871 LPS 7864 6559 4555 SEA 2805 2282 2835 HSA-LNFP-III 1967 1682 121 1 HSA-LNT 1038 1298 912 HSA-Ley 3860 3955 3076 HSA 1247 1214 1089 The greatest response was observed with the Lewisy conjugate as the stimulant. A less vigorous response was seen with SEA and the LNFP-III conjugate, both of which expresses the Lewis x antigen. No response was seen with the LNT conjugate. The results shown in Table I indicate that granuloma macrophages can produce IL-10 upon stimulation with compounds comprising a Lewis antigen, in particular a Lewisy antigen. EXAMPLE 2: In this example, the ability of peripheral blood mononuclear cells (PBMCs) from humans suffering from various disorders to produce IL-10 upon stimulation with various oligosaccharide conjugates was examined. Human PBMCs were obtained from: l) an individual who was allergic to pollen; 2) an individual suffering from lung carcinoma and 3) an individual suffering from colon carcinoma. One million PBMC in RPMI- 1640 medium containing 10 % human AB serum were incubated with either no stimulant (i.e., medium alone; a negative control), lipopolysaccharide (LPS; at 20 μg/ml; a positive control), various sugars conjugated to human serum albumin (at 100 μg/ml) or human serum albumin alone (HSA; at 100 μg/ml; a negative control). The sugar conjugates tested were lacto-jV-fucopentaose I (LNFP-I), lacto-/V-fucopentaose III (LNFP-III), lacto-N-neotetraose (LNT) and Le isy (Ley). After 24 hours, the level of IL-10 (in pg/ml) in the supematant was determined by two-site ELISA as described by in Example 1 , using an anti-human IL- 10 monoclonal antibody obtained from PharMingen. Additionally, cellular proliferation was measured by standard 3 H-thymidine uptake at 90 hours. The results are shown below in Table II. Table II: Responses of Human Cells from Allergic or Cancer Patients to Various Sugar Conjugates POLLEN ALLERGIC LUNG CARCINOMA COLON CARCINOMA STIMULANT CPM IL-10 CPM IL-10 CPM IL-10 Medium 649 160 143 1200 30 0 LPS 1946 906 232 1400 222 8221 HSA-LNFP-I 490 432 3452 10000 423 347 HSA-LNFP-III 1456 442 137 1000 270 202 HSA-LNT 1 133 220 141 1000 186 304 HSA-Ley 5960 736 458 1200 934 689 HSA 460 166 152 1200 141 0 The greatest response by cells ofthe pollen allergic individual was observed with the Lewisy conjugate as the stimulant. Less vigorous responses were seen with the LNFP-I and LNFP-III conjugates. A minimal response was seen with the LNT conjugate. The greatest response by cells ofthe individual suffering from colon carcinoma also was observed with the Lewisy conjugate as the stimulant. Less vigorous responses were seen with the LNFP-I, LNFP-III and LNT conjugates. For the individual with lung carcinoma, a vigorous response was observed only with the LNFP-I conjugate. The results shown in Table II indicate that human PBMCs from individuals suffering from various disorders (e.g., allergies or cancers) can produce IL-10 upon stimulation with compounds comprising a Lewis antigen. EXAMPLE 3: In this example, the ability of peripheral blood mononuclear cells (PBMCs) from three humans with B lymphomas to produce IL-10 upon stimulation with various oligosaccharide conjugates was examined. One million PBMC in RPMI-1640 medium containing 10 % human AB serum were incubated with either no stimulant (i.e., medium alone; a negative control), lipopoly saccharide (LPS; at 20 μg/ml; a positive control), various sugars conjugated to human serum albumin (at 100 μg/ml) or human serum albumin alone (HSA; at 100 μg/ml; a negative control). The sugar conjugates tested were lacto-N-fucopentaose I (LNFP-I), lacto-N-fucopentaose III (LNFP-III), lacto-N- neotetraose (LNT), Lewisy (Ley) and lacto-N-difucohexose I (LND). After 24 hours, the level of IL-10 (in pg/ml) in the supematant was determined by two-site ELISA as described by in Example 2. Additionally, cellular proliferation was measured by standard 3 H -thymidine uptake at 90 hours. The results are shown below in Table III. Table HI: Responses of Human PBMC from B Lymphoma Patients to Various Sugar Conjugates B-LYMPHOMA-1 B-LYMPHOMA-2 B-LYMPHOMA-3 STIMULANT CPM IL-10 CPM IL-10 CPM 1L-10 Medium 444 814 288 0 1710 0 LPS 80424 6053 1084 201 3424 1049 HSA-LNFP-I 889 2422 970 0 4504 0 HSA-LNFP-III 459 4386 1009 0 3425 64 HSA-LNT 444 1081 731 0 3530 39 HSA-Ley 621 1 6786 1099 2 5838 210 HSA-LND 1214 3521 502 307 4324 0 HSA 248 945 660 0 3149 0 The greatest response by cells ofthe B-lymphoma-1 patient was observed with the Lewisy conjugate as the stimulant. Less vigorous responses were seen with the LNFP-I, LNFP-III and LND conjugates. Similarly, the greatest response by cells ofthe B-lymphoma-3 patient was observed with the Lewisy conjugate as the stimulant. Less vigorous responses were seen with the LNFP-III and LNT conjugates. For the B- lymphoma-2 patient, a vigorous response was observed only with the LND conjugate, which expresses the Lewis 0 oligosaccharide. The results shown in Table III indicate that human PBMCs from individuals suffering from B lymphomas can produce IL-10 upon stimulation with compounds comprising a Lewis antigen. EXAMPLE 4: In this example, the ability of splenocytes from uninfected mice or mice infected with S. mansoni to produce IL-10 or IL-4 was examined upon stimulation ofthe cells with various oligosaccharide conjugates having different sugar densities. In particular, the stimulatory ability of LNFP III-HSA (which comprises the Lewis x antigen) was compared to conjugates of Lewis 3 antigen, Lewis x antigen, sialyl-Lewis x antigen or sialyl-Lewis 3 antigen to a polyacrylamide (PAA) carrier molecule. The PAA conjugates (obtained from GlycoTech, Rockville, MD) have a ligand density approximately 5-6 fold higher than that ofthe HSA conjugate. Within the LNFP III-HSA conjugate, approximately 10-12 sugar molecules/HSA molecule are present. The total conjugate weight is 67 kD, of which the LNFP III molecules comprise approximately 3.5-4.0 % of the total weight. Thus, when 50 μg/ml of LNFP III-HSA conjugate is used for stimulation, the actual concentration of sugar used is between 1.5 and 2.0 μg/ml. Within the polyacrylamide conjugates, approximately 25-30 sugar molecules/PAA molecule are present. The total conjugate is approximately 30 kD, of which the Lewis antigens comprise approximately 20-24 % ofthe total weight. Thus, when 50 μg/ml of Lewis antigen-PAA conjugate is used for stimulation, the actual concentration of sugar used is approximately 10-12 μg/ml. In these experiments unfractionated splenocytes isolated from 7-week S. mansoni-infected CBA/J mice or uninfected mice were used. The splenocytes were incubated either with media alone, Con A (50 μg/ml), LPS (50 μg/ml), anti-IgM (25 μg/ml) (all as controls), SEA (5-10 μg/ml), HSA-LNFP III (50 μg/ml), Lewis 3 -PAA (2, 10 or 50 μg/ml), Lewis x -PAA (2, 10 or 50 μg/ml), sialyl-Lewis x -PAA (2, 10 or 50 μg/ml) or sialyl-Lewis 3 -PAA (2, 10 or 50 μg/ml). Proliferation ofthe splenocytes was assessed by standard tritiated thymidine uptake. The results are shown in Figures IA, IB, IC and ID. Lewis 3 , Lewis x , sialyl- Lewis x and sialyl-Lewis 3 , each conjugated to PAA, did not stimulate proliferation of the splenocytes from either infected or uninfected mice. The level of IL-10 production was assessed as described in Example 1. The results are shown in Figures 2A, 2B, 2C and 2D. Lewis 3 , Lewis x , sialyl-Lewis x and sialyl-Lewis 3 , each conjugated to PAA, were able to stimulate IL-10 production by splenocytes from infected mice and were substantially more effective at stimulating IL- 10 production than LNFP III-HSA (compare Fig. 2A and Fig. 2B). For example, 50 μg/ml of LNFP III-HSA stimulated the production of approximately 1000 pg/ml of IL- 10 (see Fig. 2A), whereas the same amount of Lewis x -PAA and sialyl-Lewis a -PAA stimulated production of approximately 17,500 pg/ml of IL- 10 and the same amount of Lewis a -PAA and sialyl-Lewis x -PAA stimulated production of approximately 7,500 pg/ml of IL-10 (see Fig. 2B). Lewis x -PAA was also able to stimulated IL-10 production by splenocytes from uninfected mice (e.g., production of approximately 600 pg/ml of IL-10 was stimulated by 50 μg/ml of Lewis x -PAA, whereas the same amount of LNFP III-HSA did not stimulate IL-10 production by splenocytes from uninfected mice; compare Figs. 2C and 2D). The level of IL-4 production in the cultures was assessed by a standard ELISA using an anti-mouse IL-4 monoclonal antibody obtained from PharMingen. The results are shown in Figures 3A, 3B, 3C and 3D. The Lewis x -PAA was effective at stimulating IL-4 production by splenocytes from both uninfected and infected mice (see Figs. 3B and 3D). Sialyl-Lewis a -PAA stimulated lower amounts of IL-4 production in splenocytes from infected mice (see Fig. 3B), as did LNFP III-HSA (see Fig. 3A), whereas these conjugates did not stimulate IL-4 production by splenocytes from uninfected mice (see Figs. 3C and 3D). These results demonstrate that Lewis antigen-containing sugar conjugates, in particular those with a high sugar density, can stimulate IL-10 and IL-4 production by naive splenocytes (i.e., splenocytes from uninfected mice). In particular, IL-4 production was greater by stimulated naive splenocytes than stimulated splenocytes from infected mice. This IL-4 production likely is not by B cells. Rather this IL-4 production is likely by T cells and or other non-T, non-B cells (e.g., mast cells, basophils and/or eosinophils). EXAMPLE 5: In this example, the ability of Lewis antigen containing compounds to influence IgE production was examined. Three different antigen systems (HSA, phospholipase A (PLA 2 ) from bee venom, and SEA) were used. Cross-linked sugars were examined for their ability to enhance specific and total IgE production, whereas free sugars were examined for their ability to inhibit specific and total IgE production. In all experiments, the antigen, with or without free or cross-linked sugar, was administered intranasally to mice. In first series of experiments, human serum albumin (HSA), normally a poorly immunogenic antigen, was used as the antigen to elicit an IgE response. Mice were administered intranasally either saline (negative control), HSA alone, HSA-LNFPIII conjugate, HSA-LNT conjugate or HSA together with free LNFPIII. Titers ofthe following antibodies in the sera ofthe animals were then determined: total IgE, HSA- specific IgE and Lewis x -specific IgE. The results for this experiment are summarized in the bar graphs of Figures 4A, 4B and 4C, respectively. Figure 4A demonstrates that administration of LNFPIII conjugated to HSA (HSA-LNFPIII) does not increase total IgE production as compared to administration of HSA alone (compare the second and third sets of bars in Figure 4A). However, coadministration of free LNFPIII with HSA results in an approximately 60% reduction in the levels of total IgE as compared to administration of HSA alone (compare the second and fifth sets of bars in Figure 4A). The HSA-specific IgE titers, summarized in Figure 4B, demonstrate that administration of HSA alone results in virtually no specific IgE production (see the second set of bars in Figure 4B), which is what one would expect for such a poorly immunogenic molecule. In contrast, when mice are administered the HSA-LNFPIII conjugate, there is a phenomenal enhancement of HSA-specific IgE production. This response correlates with the presence ofthe Lewis x moiety on LNFPIII, since administration of HSA-LNT (which lacks the Lewis x moiety) does not result in this response. Figure 4C demonstrates that LNFPIII in the HSA-LNFPIII conjugate functions solely as an adjuvant in enhancing specific IgE responses to HSA in this experiment, since no IgE antibodies specific for the Lewis x trisaccharide were detected. , In the second series of experiments, phospholipase A (PLA ), a known allergen from bee venom, was used as the antigen to elicit IgE responses. Mice were administered intranasally either saline (negative control), PLA 2 alone, PLA 2 together with free LNFPIII or PLA 2 together with free LNT. Titers ofthe following antibodies in the sera ofthe animals were then determined: total IgE and PLA -specific IgE. The results for this experiment are summarized in the bar graphs of Figures 5A and 5B, respectively. Figure 5 A demonstrates that administration of PLA 2 alone elicits a strong total IgE response (see the second set of bars in Figure 5 A), thereby demonstrating that PLA is a much stronger immunogen than HSA in this regard. Coadministration of free LNFPIII, but not free LNT, with PLA 2 lowered the total IgE response by approximately 70% compared to administration of PLA 2 alone (compare the second and third sets of bars of Figure 5 A with the second and fourth sets of bars of Figure 5A), demonstrating that the unconjugated form ofthe Lewis x -containing compound was effective in inhibiting the total IgE response elicited by PLA . The results for the PLA 2 -specific IgE titers, summarized in Figure 5B, are similar: PLA 2 alone elicits a strong PLA 2 -specific IgE response (see the second set of bars in Figure 5B), which specific response can be inhibited by coadministration of free LNFPIII but not free LNT (see the third and fourth sets of bars in Figure 5B). Free LNFPIII reduced the PLA 2 -specific IgE response by approximately 40% in the experiment shown in Figure 5B. In a third series of experiments, SEA (a highly immunogenic mixture of antigens found in the saline soluble extract of schistosome eggs) was used as the antigen to elicit IgE responses. Mice were administered intranasally either saline (negative control), SEA alone, SEA together with free LNFPIII or SEA together with free LNT. Titers of the following antibodies in the sera ofthe animals were then determined: total IgE and SEA-specific IgE. The results for this experiment are summarized in the bar graphs of Figures 6A and 6B, respectively. Similar to PLA , SEA alone elicits a strong total IgE response (see the second set of bars in Figure 6A). For this antigen, the total IgE response was only marginally inhibited by coadministration of free LNFPIII, whereas coadministration of free LNT had a greater inhibitory effect (see the third and fourth bars in Figure 6A). For the SEA-specific IgE response, however, once again coadministration ofthe antigen and free LNFPIII resulted in a marked decrease in the antigen-specific IgE response as compared to administration ofthe antigen alone (compare the second and third bars in Figure 6B). Coadministration of free LNT was significantly less effective than free LNFPIII in inhibiting the antigen-specific IgE response (see the fourth bar in Figure 6B). Taken together, the results from the experiments in this example demonstrate that polylactosamine sugars ofthe invention (e.g., Lewis antigen containing compounds, such as Lewis x -containing compounds) are effective in modulating IgE responses in vivo, with the conjugated form of the sugars acting to stimulate antigen-specific IgE responses and the free (i.e., unconjugated) form ofthe sugars acting to inhibit antigen- specific IgE, and in certain cases total IgE, responses. In view ofthe effect of these compounds on IgE responses, the unconjugated forms ofthe Lewis antigen containing compounds of the invention can be used to inhibit IgE-mediated allergic responses, for example by administering the free sugars in the presence of an allergan to which a subject is exposed environmentally or by coadministering the free sugar and the allergan to the subject. EXAMPLE 6: In this example, the ability of cross-linked Lewis antigen containing compounds to enhance specific IgG production was examined. For these experiments, Balb/C mice were immunized intranasally with either saline (negative control), HSA, HSA-LNFPIII, HSA-LNT or HSA together with free LNFPIII. Sera was obtained from the immunized animals and diluted 1 :400. Titers of specific antibodies of particular isotypes were determined by ELISA. More specifically, ELISAs were performed using either HSA- LNFPIII, HSA-LNT or HSA as the antigen bound to the ELISA plate, to determine the specificity ofthe antibodies. Various secondary antibodies were used to quantitate the amount of antigen-specific IgM, IgG, IgGl, IgG2a, IgG2b or IgG3 antibodies in the sera. Ofthe various immunization protocols, only immunization with HSA-LNFPIII gave rise to significant levels of antibody production. The ELISA analyses of sera obtained from HSA-LNFPIII-immunized mice are summarized in the bar graphs of Figures 7A, 7B and 7C. Figure 7A, which shows ELISA results with HSA-LNFPIII as the antigen bound to the plate, demonstrates that immunization ofthe animals with HSA-LNFPIII dramatically enhances the production of both IgM and IgG antibodies. The antibodies are primarily ofthe IgGl isotype, along with some IgG2a and IgG2b isotypes. Figure 7B, which shows ELISA results with HSA-LNT as the antigen bound to the plate, is a control to show that the IgG response elicited by HSA-LNFPIII is specific for HSA and not for LNFPIII, since the IgG antibodies from the HSA-LNFPIII immunized mice also bound to HSA-LNT. In contrast, the IgM response seen in Figure 7A, when HSA-LNFPIII was used as the ELISA antigen, was not seen in Figure 7B, when HSA-LNT was used as the ELISA antigen, indicating that the IgM response likely was against LNFPIII and not HSA. Figure 7C, which shows ELISA results with HSA as the antigen bound to the plate, further confirms that the IgG adjuvant enhancing effect of LNFPIII is HSA-specific. In fact, the levels of anti-HSA antibodies seen in Figure 7C in animals immunized with HSA-LNFPIII are identical to the levels of antibodies seen in Figure 7A, except for the lack of IgM antibodies to HSA in Figure 7C. These results further confirm that the observed IgM response likely is specific for LNFPIII, whereas the enhanced IgG responses are specific for HSA. The results described in this example clearly demonstrate that LNFPIII (which expresses the Lewis x antigen), when administered in a cross-linked form, is able to dramatically enhance specific IgG production in vivo to a normally weak antigen such an HSA in a naive animal. EXAMPLE 7: In this example, similar experiments to those described in Examples 5 and 6 were performed using HSA-LNFPIII as the agent for stimulating IgE and IgG responses in vivo. To examine the dose dependency ofthe observed stimulatory effect, animals were immunized intranasally with increasing amounts of HSA-LNFPIII (0.01 μg, 0.1 μg, 1 μg or 10 μg). HSA alone (10 μg) was used as a control. Production of total IgE, HSA-specific IgE and HSA-specific IgM and IgG antibodies was quantitated as described for Examples 5 and 6. The results are summarized in the bar graphs of Figures 8A, 8B and 8C, which demonstrate that HSA-LNFPIII stimulates production of total IgE, HSA-specific IgE and HSA-specific IgG and IgGl in a dose dependent manner. As little as 1 μg of HSA-LNFPIII was capable of stimulating significantly greater HSA-specific IgE and IgG production than 10 μg of HSA alone. It should be noted that the doses in these experiments refer to the total amount, by weight, of HSA or HSA-LNFPIII conjugate. As there are only on average about 10 molecules of LNFPIII for every molecule of HSA, these experiments demonstrate that the amount of sugar needed to enhance the antibody response in vivo is very small. EXAMPLE 8: In this example, the types of cells responsive to the multimeric sugar conjugates, and the types of cytokines produced, either in vitro or in vivo, were investigated further. For the in vitro studies, naive splenocytes were isolated from CBA mice and fractionated into T cell, B cell and non-T, non-B spleen cell populations. B cell populations were defined by expression ofthe B220 surface marker (i.e., B220 + cells). T cell populations were defined by expression of CD5 or Thy surface markers (i.e., CD5 + or Thy + ). Production of either IL- 10 or IFN-γ by the various cell populations in response to culture with either media alone (negative control), ConA (positive control), LPS (positive control), LNFPIII-HSA or LNT-HSA was analyzed, the results of which are summarized below in Table IV. Table IV: Cytokine Production In vitro by Spleen Cell Subpopulations IL-10 Total Non-B Non-T Non-T B cells T cells T cells (μg ml) Spleen (B220-) (CD5-) (Thy-) (B220+) (CD5+) (Thy+) media 0 0 0 0 0 0 0 ConA 150 458 155 497 132 15 0 LPS 535 320 430 430 552 264 72 LNFPIII- 552 364 552 475 617 207 201 HSA LNT- 0 0 0 0 0 0 0 HSA IFN-γ Total Non-B Non-T Non-T B cells T cells T cells (μg/ml) Spleen (B220-) (CD5-) (Thy-) (B220+) (CD5+) (Thy+) media 0 0 0 0 0 0 0 ConA 3432 14316 2413 8884 1035 885 1 19 LPS 47 321 0 0 0 403 617 LNFPIII- 0 273 0 0 0 349 790 HSA LNT- 0 66 0 0 0 0 24 HSA The results shown in Table IV confirm that naive B cell, T cell and non-T, non-B spleen cells respond to the Lewis x -containing compound LNFPIII-HSA by producing IL-10. The T cell population also produced IFN-γ in vitro and, in data not shown in Table IV, also produced IL-4 and IL-5. In further experiments, spleen cells from five different strains of mice were tested for responsiveness to the multimeric sugar conjugates in vitro. The five strains tested were: CBA/J, Balb/c, C57/B6, RAG-KO (in which the RAG2 gene has been functionally disrupted, thereby disrupting immunoglobulin expression) and Z-KO (in which the TCR-zeta chain gene has been functionally disrupted, thereby disrupting T cell receptor expression). Spleen cells from all five strains of mice produced Th2- associated cytokines (e.g., IL-10, IL-4, IL-5) in response to stimulation with the sugar conjugates (e.g., LNFPIII-HSA or Lewis x -PAA), demonstrating that this response is independent ofthe genetic background ofthe spleen cell donors. Furthermore, the fact that both the RAG-KO strain and the Z-KO strain respond to the sugar conjugates indicates that neither the TCR nor immunoglobulin are involved as receptors for the sugars or in signalling events for sugar-induced cytokine production. In a separate series of experiments, the cytokine responses from nasal lymphocytes obtained from animals immunized intranasally with HSA or HSA-LNFPIII was examined. After priming and boosting with either HSA or HSA-LNFPIII in vivo. nasal lymphocytes were recovered from the immunized animals. The nasal lymphocytes were then cultured in vitro for 72 hours and the culture supematant examined for cytokine production (thus, there was no in vitro recall with the antigen). The results for IL-4, IL-5, IL-10 and IFN-γ production are shown in the bar graphs of Figures 9A, 9B, 9C and 9D, respectively. These results demonstrate that in vivo priming and boosting with HSA-LNFPIII (either 1.0 or 10 icrograms) leads to markedly increased production of IL-4, IL-5 and IL-10 by nasal lymphocytes, compared to priming and boosting with HSA alone (see Figures 9A, 9B and 9C). Production of IFN-g by the nasal lymphocytes was not observed (see Figure 9D). This is in contrast to the results for splenic T cells cultured in vitro with the sugar conjugates, discussed above, which did display some IFN-γ production. Thus, while in vitro stimulation of cells leads to production of Th2 -associated cytokines but may also lead to production of certain Thl- associated cytokines (at least under certain conditions or using certain cell types), the results with the nasal lymphocytes demonstrates that in vivo priming and boosting with the sugar conjugate leads to amplification strictly of Th2-associated cytokine responses (e.g., IL-4, IL-5 and IL-10). EXAMPLE 9: In this example, the ability of Lewis antigen-containing compounds to stimulate Th2 -associated cytokine production from naive human peripheral blood mononuclear cells (PBMCs) was examined. PBMCs were obtained from two normal individuals. Subject 1 was blood type O. Subject 2 was blood type AB. PBMCs were purified by Ficoll-Paque gradient centrifugation. The purified PBMCs were cultured in vitro with various sugar conjugates and IL-10 levels in the supematant were determined 72 hours later by ELISA. The results are summarized below in Table V. Table V: Stimulation of IL-10 Production from Naive Human PBMCs Levels of IL-10 (picograms/ml) Stimulants Subject 1 Subject 2 Media 8 7 Lewisy-PAA 11 29 Lewis a -PAA 48 52 HSA 97 5 LNT-HSA 131 181 LNFPIII-HSA 1971 576 This experiment demonstrates that naive human PBMCs (i.e., PBMCs from humans that are not suffering from a disease or disorder and that have not been specifically pre-immunized) respond to stimulation with multimeric forms of Lewis antigen-containing compounds, in particular LNFPIII-HSA (which comprises the Lewis x moiety), by producing the Th2-associated cytokine IL-10. EQUIVALENTS Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments ofthe invention described herein. Such equivalents are intended to be encompassed by the following claims.

Claims: CLAIMS 1. Use of an agent that modulates interaction of a compound comprising a Lewis antigen with a human immune cell in the preparation of a medicament for modulating production by a human immune cell of at least one cytokine that regulates development of a T helper type 1 (Thl) or T helper type 2 (Th2) response. 2. Use of an agent that modulates interaction of a compound comprising a Lewis antigen with a macrophage in the preparation of a medicament for modulating production by the macrophage of at least one cytokine that regulates development of a T helper type 1 (Thl) or T helper type 2 (Th2) response. 3. Use of an agent that modulates interaction of a compound comprising a Lewis antigen with a T cell in the preparation of a medicament for modulating production by the T cell of at least one cytokine that regulates development of a T helper type 1 (Thl) or T helper type 2 (Th2) response. 4. The use of claim 1, 2 or 3, wherein the medicament stimulates production of IL-10 in a subject. 5. The use of claim 1, 2, or 3, wherein the agent is a stimulatory form of a compound comprising a Lewis antigen. 6. The use of claim 1, 2 or 3, wherein the agent is a stimulatory form of a compound comprising a Lewisy oligosaccharide or a derivative thereof. 7. The use of claim 1 , 2 or 3, wherein the agent is a stimulatory form of a compound comprising a Lewis x oligosaccharide or a derivative thereof. 8. The use of claim 1 , 2 or 3, wherein the agent is a stimulatory form of a compound comprising a Lewis 3 oligosaccharide or a derivative thereof, or a Lewis 0 oligosaccharide or a derivative thereof. 9. The use of claim 1 , 2 or 3, wherein the medicament inhibits production of IL-10 in a subject. 10. The use of claim 1, 2, or 3, wherein the agent is an inhibitory form of a compound comprising a Lewis antigen. 1 1. The use of claim 1, 2 or 3, wherein the agent is an inhibitory form of a compound comprising a Lewisy oligosaccharide or a derivative thereof. 12. The use of claim 1, 2 or 3, wherein the agent is an inhibitory form of a compound comprising a Lewis x oligosaccharide or a derivative thereof. 13. The use of claim 1 , 2 or 3, wherein the agent is an inhibitory form of a compound comprising a Lewis 3 oligosaccharide or a derivative thereof, or a Lewis 0 oligosaccharide or a derivative thereof. 14. A pharmaceutical composition comprising an agent that modulates interaction of a compound comprising a Lewis antigen with human immune cells of a human subject in an amount sufficient to modulate production by the human immune cells of at least one cytokine that regulates development of a T helper type 1 (Thl) or a T helper type 2 (Th2) response when the agent is administered to the human subject, and a pharmaceutically acceptable carrier. 15. A pharmaceutical composition comprising an agent that modulates interaction of a compound comprising a Lewis antigen with macrophages of a subject in an amount sufficient to modulate production by the macrophages of at least one cytokine that regulates development of a T helper type 1 (Thl) or a T helper type 2 (Th2) response when the agent is administered to the subject, and a pharmaceutically acceptable carrier. 16. A pharmaceutical composition comprising an agent that modulates interaction of a compound comprising a Lewis antigen with T cells of a subject in an amount sufficient to modulate production by the T cells of at least one cytokine that regulates development of a T helper type 1 (Thl) or a T helper type 2 (Th2) response when the agent is administered to the subject, and a pharmaceutically acceptable carrier. 17. The pharmaceutical composition of claim 14, 15 or 16, wherein the agent is a stimulatory form of a compound comprising a Lewis antigen. 18. The pharmaceutical composition of claim 14, 15 or 16, wherein the agent is a stimulatory form of a compound comprising a Lewisy oligosaccharide or a derivative thereof. 19. The pharmaceutical composition of claim 14, 15 or 16, wherein the agent is a stimulatory form of a compound comprising a Lewis x oligosaccharide or a derivative thereof. 20. The pharmaceutical composition of claim 14, 15 or 16, wherein the agent is a stimulatory form of a compound comprising a Lewis 3 oligosaccharide or a derivative thereof, or a Lewis 0 oligosaccharide or a derivative thereof. 21. The pharmaceutical composition of claim 14, 15 or 16, wherein the agent is an inhibitory form of a compound comprising a Lewis antigen. 22. The pharmaceutical composition of claim 14, 15 or 16, wherein the agent is an inhibitory form of a compound comprising a Lewisy oligosaccharide or a derivative thereof. 23. The pharmaceutical composition of claim 14, 15 or 16, wherein the agent is an inhibitory form of a compound comprising a Lewis x oligosaccharide or a derivative thereof. 24. The pharmaceutical composition of claim 14, 15 or 16, wherein the agent is an inhibitory form of a compound comprising a Lewis 3 oligosaccharide or a derivative thereof, or a Lewis 0 oligosaccharide or a derivative thereof. 25. The pharmaceutical composition of claim 14, 15 or 16, which is suitable for intranasal delivery. 26. The pharmaceutical composition of claim 14, 15 or 16, which is suitable for oral delivery. 27. The pharmaceutical composition of claim 14, 15 or 16, which is packaged with instructions for using the pharmaceutical composition to modulate an immune response. 28. The pharmaceutical composition of claim 14, 15 or 16, which is packaged with instructions for using the pharmaceutical composition as an adjuvant. 29. The pharmaceutical composition of claim 14, 15 or 16, which is packaged with instructions for using the pharmaceutical composition to modulate an allergic response. 30. The pharmaceutical composition of claim 14, 15 or 16, which is packaged with instructions for using the pharmaceutical composition to modulate an autoimmune disease. 31. A pharmaceutical composition comprising a conjugate of a Lewis antigen, or derivative thereof, and a carrier molecule, wherein the Lewis antigen, or derivative thereof, comprises at least 10 % ofthe conjugate by weight, the conjugate being in an amount sufficient to stimulate production of at least one cytokine that regulates development of a T helper type 1 (Thl) or a T helper type 2 (Th2) response when the conjugate is administered to the subject, and a pharmaceutically acceptable carrier. 32. The pharmaceutical composition of claim 31 , wherein the Lewis antigen, or derivative thereof, comprises at least 15% of the conjugate by weight. 33. The pharmaceutical composition of claim 31 , wherein the Lewis antigen, or derivative thereof, comprises at least 20% ofthe conjugate by weight. 34. The pharmaceutical composition of claim 31 , wherein the Lewis antigen, or derivative thereof, comprises at least 25% ofthe conjugate by weight. 35. Use of a stimulatory form of an agent comprising a Lewis antigen in the preparation of an adjuvant for stimulating a specific immune response to an antigen. 36. The use of claim 35, wherein the agent comprises Lewisy oligosaccharide or a derivative thereof. 37. The use of claim 35, wherein the agent comprises a Lewis x oligosaccharide or a derivative thereof. 38. The use of claim 35, wherein the agent comprises a Lewis 3 oligosaccharide or a derivative thereof, or a Lewis 0 oligosaccharide or a derivative thereof. 39. Use of an inhibitory form of an agent comprising a Lewis antigen in the preparation of a medicament for treating an allergy. 40. The use of claim 39, wherein the agent comprises Lewisy oligosaccharide or a derivative thereof. 41. The use of claim 39, wherein the agent comprises a Lewis x oligosaccharide or a derivative thereof. 42. The use of claim 39, wherein the agent comprises a Lewis a oligosaccharide or a derivative thereof, or a Lewis* 5 oligosaccharide or a derivative thereof. 43. A method of stimulating a specific immune response to an antigen in a subject comprising: administering to the subject: (i) the antigen and (ii) a stimulatory form of an agent comprising a Lewis antigen, such that a specific immune response to the antigen is stimulated in the subject. 44. The method of claim 43, wherein the agent comprises a Lewisy oligosaccharide or a derivative thereof. 45. The method of claim 43, wherein the agent comprises a Lewis x oligosaccharide or a derivative thereof. 46. The method of claim 43, wherein the agent comprises a Lewis 3 oligosaccharide or a derivative thereof, or a Lewis 0 oligosaccharide or a derivative thereof. 47. The method of claim 43, wherein the agent is administered intranasally. 48. The method of claim 43, wherein the agent is administered orally. 49. The method of claim 43, wherein the agent is administered intravenously. 50. The method of claim 43, wherein the agent is administered intramuscularly. 51. The method of claim 43, wherein the agent is administered subcutaneously. 52. The method of claim 43, wherein the agent is administered mucosally. 53. A method of inhibiting an IgE response to an allergan in a subject comprising administering to the subject, in the presence ofthe allergan, an inhibitory form of an agent comprising a Lewis antigen, such that an IgE response to the allergan is inhibited in the subject. 54. The method of claim 53, wherein the agent comprises a Lewisy oligosaccharide or a derivative thereof. 55. The method of claim 53, wherein the agent comprises a Lewis x oligosaccharide or a derivative thereof. 56. The method of claim 53, wherein the agent comprises a Lewis 3 oligosaccharide or a derivative thereof, or a Lewis 0 oligosaccharide or a derivative thereof. 57. The method of claim 53, wherein the agent and the allergan are coadministered to the subject. 58. A method for stimulating production of a Th2-associated cytokine by a cell in vitro comprising: contacting the cell in vitro with a stimulatory form of an agent comprising a Lewis antigen such that production of a Th2-associated cytokine by the cell is stimulated, wherein the cell is selected from the group consisting of a T cell, a macrophage and a non-T, non-B spleen cell. 59. The method of claim 58, wherein the Th2-associated cytokine is IL-10. 60. The method of claim 58, wherein the Th2-associated cytokine is IL-4. 61. The method of claim 58, wherein the Th2-associated cytokine is IL-5. 62. The method of claim 58, wherein the agent comprises a Le is oligosaccharide or a derivative thereof. 63. The method of claim 58, wherein the agent comprises a Lewis x oligosaccharide or a derivative thereof. 64. The method of claim 58, wherein the agent comprises a Lewis 3 oligosaccharide or a derivative thereof, or a Lewis 0 oligosaccharide or a derivative thereof.

Inventors: HARN DONALD A, VELUPILLAI PALANIVEL, HARN, DONALD, A., VELUPILLAI, PALANIVEL
Applicants: HARN DONALD A, HARVARD COLLEGE, VELUPILLAI PALANIVEL, HARN, DONALD, A., PRESIDENT AND FELLOWS OF HARVARD COLLEGE, VELUPILLAI, PALANIVEL
Application year: 1997
Main classification: A61K39
IPC codes: A61K31, A61K38, A61K39, A61P37