PRESENTATION OF HYDROPHOBIC ANTIGENS TO T-CELLS BY CD1 MOLECULES

Abstract: Provided are CD1 presented antigens, compositions, cells, inhibitors and methods relating to the use of lipoarabinomannan (LAM) antigen presentation by CD1 molecules, including: methods for detecting the presence of a CD1-presented LAM antigen in a sample; methods for isolating such CD1-presented LAM antigens and the isolated antigens; vaccines containing CD1-presented LAM antigens and vaccination methods; methods of blocking CD1 LAM antigen presentation; methods of identifying and/or isolating CD1 blocking agents and the isolated CD1 blocking agents; methods of inducing CD1 expression; and T-cells for use in the methods disclosed herein.

Description: Presentation of Hydrophobic Antigens to T-Cells by CDl Molecules Description of the Background Art The Immune System and T-cells Animals have a complex array of molecular and cellular defenses, collectively referred to as the immune system, that recognize and attack potentially harmful foreign or endogenous but abnormal cells (respectively represented by, e.g., pathogens such as bacteria or viruses, and cancerous or pathogen-infected cells), but tolerate endogenous normal cells. When stimulated by foreign or abnormal biomolecules, the immune system undergoes a series of activities designed to neutralize and destroy the pathogens, or cancerous or pathogen-infected cells, with which the foreign or abnormal biomolecules are associated. These activities, collectively known as an immune response, may consist of a cell-mediated immune response, a humoral (antibody-mediated) immune response, or an immune response that includes elements of cell-mediated and humoral responses. Humoral immune responses are mediated by antibodies that bind specific foreign or abnormal biomolecules. Antibodies are immunoglobulin (Ig) molecules produced by B-cells, as lymphocytes which originate in avian bursa or in mammalian bone marrow, but migrate to and mature in other organs, particularly the spleen. Robertson, M., Nature 301:114 (1983). Cell- mediated immune responses are the result of activities of T- ells , lymphocytes that undergo maturation within the th mus of an animal. Tizard, I.R., Immunology: An Introduction, 2d Ed., Saunders, Philadelphia (hereafter "Tizard"), p. 163, 1988. Both T and B-cells migrate between various organs and/or tissues within an animal's body. Lydyard, P., and Grossi, C, Chapter 3 in Immunology, 2d Ed., Roitt, I., et al., eds ' ., Gower Medical Publishing, London, New York, 1989. T-cells mediate at least two general types of immunologic functions, effector and regulatory, reflecting the fact that T-ceil activities vary considerably among different subpopulations of T-cells within an animal. Rook, G., Chapter 9 in Immunology, 2d Ed., Roitt, I., et al., eds., Gower Medical Publishing, London, New York, 1989. Effector functions include delayed hypersensitivity, allograft rejection, tumor immunity, and graft- versus-host reactivity. Effector functions reflect the ability of some T-cells to secrete proteins called lymphokines, and the ability of other T-cells ("cytotoxic" or "killer" T-cells) to kill other cells. The regulatory functions of T-cells are represented by the ability of "helper" T-cells. Helper T-cells interact with, and produce biomolecules that influence the behavior of, both B-cells and cytotoxic T-cells, in order to promote and direct antibody production and cytotoxic activities, respectively. Mosier, D.E., Science 158: 1573-1575 (1967). Other classes of T-cells, including suppressor T-cells and memory T-cells, also exist. Miedema, F. , and Melief, C.J.M., Immunol. Today 6:258-259 (1983); Tizard, pp. 225-228. Antigen Recognition In order to function properly, the T- and B-cells of an animal's immune system must accurately and reliably identify the enormous number of molecular compositions derived from foreign ("non-self"), or endogenous ("self") but abnormally expressed, compositions that are encountered. Recognition and identification by the immune system occurs at the molecular level. An antigen, a molecular composition having the potential to generate an immune response, is composed of one or more molecular-sized identifying features known as epitopes. A polypeptide antigen which has an amino acid sequence which comprises, e.g., a hundred amino acids might comprise dozens of epitopes, wherein each epitope is defined by a portion of the polypeptide comprising from about 3 to about 25 amino acids. The number of epύtopes derivable from polypeptides alone is estimated to be about ten million. Tizard, p. 25. An antigen encountered by a T or B-cell of an animal must be identified as either, being associated with normal endogenous (i.e., self) -3- antigens, an immune response to which would be injurious to the animal, or with foreign or abnormal (i.e., non-self) antigens, to which an immune response should be moimted. As part of the immune system's means of identifying antigens, individual T and B-cells produce antigen receptors which are displayed on the T or B-cell's surface and which bind specific antigens. Turner, M., Chapter 5 in Immunology, 2d Ed., Roitt, I., et al., eds., Gower Medical Publishing, London, New York, 1989. B-cells produce and display antigen receptors that comprise Ig molecules which have unique antigen- binding portions due to unique amino acid sequences in the variable regions of each of the two antibody subunits, known as the Ig heavy and Ig light chains. Each B-cell membrane comprises from 20,000 to 200,000 identical Ig molecules. Tizard, pp. 78-80 and 202. The T-cell antigen receptors (TCRs) produced by and displayed on individual T-cells comprise heavy (TCR/3) and light (TCRα) chains (polypeptide subunits) which are linked by a disulfide bond on the T-cell surface. Each TCR α and /3 subunit has a car_κ>xy-teπninal constant region, the amino acid sequence of which does not vary from T-cell to T-cell, and an amino-terminal variable region, the amino acid sequence of which does vary from T-cell to T-cell. When TCR and TCRβ subunits associate with each other, the variable regions of the TCRα and TCRβ polypeptide subunits combine to form the unique antigen-binding portion of an tt:β TCR. A second type of TCR heterodimer, γ:δ, has been described but its function, if any, is unknown. Davis, M.M., and Bjor man, P.J., Nature 334:395-404 (1988) . Although at least one mixed TCR heterodimer of unknown function, β:δ TCR, has been described, T-cells bearing a:β TCR molecules are numerically dominant in mature animals. Hochstenbach, F., and Brenner, M.B., Nature 540:562-565 (1989). Although each individual T- or B-cell displays identical- ntigen receptors, the receptor displayed varies from cell to cell; an animal's collection of different antigen receptors is thus quite diverse. The genetic basis of this diversity is as follows. The variable region of an Ig heavy chain, or that of a TCR/3 chain, is encoded by three gene segments, the variable (V), diversity (D) and joining (J) segments. The variable region of an Ig l i ght chain, or that of a TCR__ chain, is encoded by V and J gene segments. Multiple DNA sequences encoding many different V, D and J gene segments are present as unexpressed copies in geπ ή line DNA; an analogous but different collection of variable gene segments for TCR subunits is also present. During development of an animal, genes encoding diverse vaπable regions are generated in individual cells of the immune system by the random joining of V, D and J, or V and J. gene segments. The process of DNA rearrangements that generates a randomly assembled variable region of an Ig heavy or TCRβ subunit is called V-D-J joining; the analogous process that generates a rearranged variable region of an Ig light or TCR . subunit is called V-J joining. Sakano, H., etaL. Nature 250:288-294 (1979); Early. P.. etc!.. Cell 19:981-992 (1980); Alt, F.W.. et al., Science 25*1079-1087 (1987); Harlow, E., and Lane, D., Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, pages 10-18, 1988; Davis, M.M., and Bjorkman, P.J., Nature 554:395-404 (1988). A functionally rearranged Ig or TCR subunit gene is one in which the DNA rearrangements of V-D-J or V-J joining have not resulted in a reading frame that is prematurely terminated because of the introduction of stop codons or frameshifting mutations. Because each T or B-cell of the immune system expresses genes encoding their respective antigen receptors in which a unique functionally rearranged variable region is present, many different T or B-cells, each producing a receptor that has a unique antigen-recognizing region, are generated. Hay, F., Chapter 6 in Immunology, 2d Ed., Roitt. I.. et l., eds., Gower Medical Publishing, U ) ndon, New York, 1989. The total catalog of different antigen receptors dispUyed on the T-cells of an animal is referred to as the animal's TCR repertoire. Bevan, M.J., et al., Science 264:796-797 (1994). For m atιueT- orB-celk, b_ιιdi_^ activates the cell, i.e., stimulates the cell to undertake activities related to generating a cell-mediated or humoral immune response. Typically, activated mature T or B-cells proliferate in response to antigen. In contrast, for immature T or B-cells, binding of antigen to a displayed TCR or B-cell antigen receptor, respectively, results in elimination of the cell by a process called negative selection or clonal deletion. Clonal deletion occurs during normal development of a healthy wildtype animal, and is a mechanism by which the immune system learns to tolerate the animal's normal endogenous (self) antigens, i.e., to treat the animal's self antigens as non-immunogenic antigens. Failure of the immune system to achieve or maintain tolerance of self antigens may result in autoimmune responses (i.e., autoimmune response to self antigens) that can culminate in autoimmune disease in animals including humans. Autoimmune disease can occur when an appropriate immune response to a non-self antigen results in the production of immune effector biomolecules (e.g. , autoantibodies) or cells that cross-react with self antigens. Human autoimmune diseases include such crippling conditions as Multiple Sclerosis (MS) and Systemic Lupus Eiythematosus (SUE). Roitt, I., Chapter 23 in Immunology, 2d Ed., Roitt, l., etal., eds., Gower Medical Publishing, London, New York, 1989; Steinman, L., Sci. American 269:107-114 (1993). Antigen Presentation Although the antigen receptors of B-cells can directly bind soluble antigen, T-cells typically respond to antigen only when it is displayed on specific classes of other cells known generically as an antigen-presenting cells (APCs). Feldmann, M., and Male, D., Chapter 8 in Immunology, 2d Ed., Roitt, l., et al., eds., Gower Medical Publishing, London, New York, 1989. APCs, e.g., macrophages and dendritic cells, present antigens derived from polypeptides via glycoproteins, known as MHC (major histocompatibility complex) proteins, which are displayed on the surface of APCs. Bevan, M. J. , et al.. Science 264:796-797 (1994). The nomenclature for MHC gene products varies from species to species. For example, human MHC proteins are also referred to as human lymphocyte antigens (HLA), murine MHC proteins are also referred to as H-2 antigens, and rat MHC proteins are also called RT1 antigens. Tizard, p. 181. Particular MHC proteins bind selected classes of antigens with limited specificity. For the most part, the specificity deteπninants in a TCR:Ag:MHC complex are (1) the unique polypeptide sequences of the variable portion of the TCR and (2) the unique polypeptide sequences of antigen. However, to some degree, MHC-preseπtcd oligopeptide antigens are embedded within an MHC molecule and TCR recognition of antigen only occurs within the context of an appropriate class of MHC molecule. Janeway, C.A., Sci. American 269:73-79 (1993). This phenomenon, called MHC restriction, is of fundamental importance to T-cell antigen recognition and physiology. Zinkernagel, R.M., and Doherty, P.C., Nature 245:701-702 (1974). In MHC-mediated presentation of antigens, the a:β T-cell antigen receptor recognizes peptide antigens in conjunction with products of MHC genes. In the case of soluble antigens, recognition occurs in conjunction with Class II molecules. For viral antigens, recognition is in conjunction with Class I molecules. Furthermore, large soluble antigens are processed from polypeptides by an appropriate accessory cell, such as a macrophage or dendritic cell. The general sequence of events involved in T-cell recognition of polypeptide antigens in MHC restriction is as follows. A polypeptide antigen is phagocytosed by an antigen-presenting cell, internalized,- processed, and then a peptide derived from the polypeptide is displayed on the cell surface in conjunction with Class I or Class II MHC molecules. In order to present antigen, MHC Class I molecules require a additional protein, β 2 - microglobulin. Tizard, pp. 181-183. A T-cell antigen receptor a:β heterodimer then recognizes the peptide antigen plus the MHC gene product. Recognition of peptide antigen alone or MHC gene product alone is not sufficient to signal T-cell activation. Only the MHC:Ag complex can be appropriately recognized by a TCR molecule. Steward, M., Chapter 7 in Immunology, 2d Ed., Roitt, I., et al., eds., Gower Medical Publishing, London, New York, 1989. The genes encoding MHC proteins are diverse; however, unlike Ig and TCR molecules, which vary from cell to cell in an individual animal, MHC antigens vary from individual animal to individual animal or from one group of related individual animate to another group. Members of familial groups, represented in the mouse by inbred strains of mice, share similar MHC antigens with each other, but not with individuals from other strains of mice. Snell, G.D., Science 213: 172-178 (1981); Owen, M.. Chapter 4 in Immunology, 2d Ed., Roitt, I., et al., eds., Gower Medical Publishing, London, New York, 1989. Because variant MHC molecules will be capable of binding different antigens, the antigens that T-cells will be able to recognize (i.e., specifically bind in the MHC context) and respond to varies among different strains of mice. Cooke, A., Chapter 11 in Immunology, 2d Ed., Roitt, I., et al., eds., Gower Medical Publishing, London, New York, 1989. In humans, particular genetic aileles encoding MHC (HLA) molecules are more highly associated with autoimmune diseases, presumably because these MHC molecules are more competent at binding (and thus presenting to T- cells) self antigens. Vaughan, in Immunological Diseases, 3rd Ed., Vol. π, Samter, M., ed., pp. 1029-1037 (1978); Steinman, L., Sci. American 269:107-114 (1993). T-cell Subsets Classes of T-cells are to some extent distinguished on the basis that different T-cells display different CD proteins on their surfaces. Immature T- cells display both CD4 and CD8 proteins (Le., immature T-cells are CD4 + 8 + ), mature helper T-cells are CD4 + 8 " (Le., display CD4 protein but not CD8 protein) and mature cytotoxic T-cells are CD4 " 8 + (Le., display CD8 protein but not CD4 protein). Smith, L., Nature 526:798-800 (1987); Weissman, I.L., and Cooper, M.D., Sci. American 269:65-71 (1993). In most cases so far examined, CD8 + T lymphocytes recognize MHC class I complexes, while CD4 + cells recognize MHC class II complexes on antigen presenting cells. The involvement of CD8 and CD4 in antigen recognition by cr.β TCRs is significant. CD4 and CD8 molecules increase the avidity of the TCR interaction Ag:MHC complexes and are sometimes referred to as co-receptors (Bierer, B.E., et al., Ann. Rev. Immunol. 7:579- 599 (1989); Steward, M., Chapter 7 in Immunology, 2d Ed., Roitt, I., et al., eds., Gower Medical Publishing, London, New York, 1989). Because of the importance of CD4 and CD8 in antigen recognition in the MHC context, CD4"8" (double negative; DN) T-cells have classically been considered to be immature thymic T-cell precursors. Lydyard, L., and Grossi, C, Chapters 2 and 14 in Immunology, 2d Ed., Roitt, I., et al., eds., Gower Medical Publishing, London, New York, 1989; Smith, L., Nature 526:798-800 (1987); Strominger, J.L., et al., Int. J. Cancer Suppl. 4:43-47 (1989); Shirai, T., et al., J. Immunology 744:3756-3761 (1990); Weissman, I.L. and Cooper, M.D., Sci. American 269:65-71 (1993). The DN subpopulation of T-cells is distinctive in regard to the TCRs that they display. The majority of human DN T-cells isolated from peripheral blood express δ:y TCRs. Porcelli, S., et al., Immunological Reviews 720:137-183 (1991). A large proportion (approximately 60%) of murine DN :β TCR T-cells express V08 gene products (Fowlkes, B.J., et al., Nature 529:251-254 (1987); Bix, M., et al., J. Exp. Med. 775:901-908 (1993)). Several analyses in mice point to a striking lack of junctional (V-J or V-D-J) diversity and restricted use of germline V and J gene elements, especially for TCRα subunits. Koseki, H., et al., Proc. Natl. Acad. Sci. USA 57:5248-5252 (1990); Kubota, H., et al., 3. Immunol. 749:1143-1150 (1992). Iixamination of fresh DN α:/S TCR T-ceUs m hu__-__s rev_-Ued a st an invariant (canonical) Vα24-JαQ rea_τ___gem___t that lacked N region additions. PorceUi, S., et al., J. Exp. Med. 775:1-16 (1993). Taken together, these observations suggest that DN or.β TCR T-cells may represent a developmentally distinct subpopulation of T lymphocytes whose limited receptor repertoire reflects recognition of a restricted set of antigens and/or antigen-presenting molecules. CDl Proteins Polypeptide molecules encoded by the genes of the CDl locus are recognized by select CD4~8" T-cell clones expressing either :β or y:δ TCRs (PorceUi, S., et al., Nature 547:447-450 (1989); Faure, F. t et al., Eur. J. Immun. 20:703-706 (1990)). Because of the structural resemblance of CDl molecules, encoded by genes on human chromosome 1, to MHC molecules, encoded by genes on human chromosome 6 (Calabi, F. and Milstein, C, Nature 525:540-543 (1986); Balk, S.P., et al., Proc. Natl Acad. Sci. USA 56:252-256 (1989)), it has been suggested that CDl may represent a family of antigen presenting molecules separate from those encoded by the MHC genes. PorceUi, S., etal. , Nature 547:447-450 (1989); Strominger, J.L., Cell 57:895-898 (1989); PorceUi, S., et al., Immun. Rev. 720:137-183 (1991). The five CDl genes reveal exon and domain structure (αl, c_2, c_3) that is similar to that of MHC class I genes, yet the proteins are only distantly related in sequence. AU CDl family members share a conserved α3 domain; however, even this domain shows only 32% homology in amino acid sequence with consensus residues of class I MHC o3 domains and there is no detectable homology with al domains. A major difference between MHC and CDl molecules is polymorphism. Human MHC genes are extremely polymorphic: multiple alleles have been described at each known MHC locus. In contrast, CDl genes are apparently nonpolymorphic. Despite these differences, the CDl proteins, like MHC Class I molecules, are expressed as large subunits (heavy chains) non-covalently associated with S^microglobulin. Van Agthoven, A., and Terhorst, C, J. Immunol. 725:426-432 (1982); Terhorst, C, et al.. Cell 25:771-780 (1981)). Five CDl genes have thus far been identified in humans: CDla, CDlb, CDlc, CDld and CDle. Four of the five CDl gene products have been defined serologically, are referred to as CDla, CDlb, CDlc and CDld and are distinguished by unique heavy chains with approximate molecular weights of 49kDa, 45kDa, 43kDa and 48kDa respectively (Amiot, M., et al., J. Immunol. 756:1752-1758 (1986); PorceUi, S., et al., Immunol. Rev. 720:137-183 (1991); Bleicher, P.A., et al.. Science 250:679-682 (1990)). CDl proteins are displayed on a number of APCs including Langerhans cells (which are the major dendritic antigen-presenting ceUs in the skin), activated B-ceUs, dendritic ceUs in lymph nodes, and on activated blood monocytes (PorceUi, S., et al., Nature 560:593-597 (1992); Leukocyte Typing IV, Knapp, W., ed., Oxford University Press, Oxford, U.K., pp. 251-269, 1989; Tissue Antigens, Kissmeyer-Nielsen, F., ed., Munksgard, Copenhagen, Denmark, pp. 65-72, 1989. Previous work has shown that CDl proteins are recognized by CD4""8~ T-ceU lines derived from patients with SUE. PorceUi, et al. , Nature 547:447- 450 (1989). Leukemia cells expressing CDl proteins were lysed by the T- cells independent of MHC restriction, even though no foreign (non-self) antigen was present. DN T-cells lysed leukemic cells in a CDl-dependent manner in the absence of antigen. Thus, the possibility exists that CDl proteins play a role in autoimmune diseases. The central dogma of immunology has been that the immune system does not normally react to self. Autoimmunity defines a state in which the natural unresponsiveness or tolerance to self terminates. As a result, -11- antibodies or cells react with self constituents, thereby causing disease. There is as yet no established unifying concept to explain the origin and pathogenesis of the various autoimmune disorders. The disease process may be caused, among other things, by sensitized T lymphocytes. These lymphocytes produce tissue lesions by poorly understood mechanisms which may involve the release of destructive lymphokines or which attract other inflammatory cells to the lesion. For a review of autoimmunity, see Theofilopoulos, A.N., Chapter 11 in Basic and Clinical Immunology, 6th Ed., Stites, D.P., et al., eds., Appleton and Lang, 1987. Tuberculosis Mycobacteria are a genus of aerobic intracellular bacterial organisms which upon invasion of their host, survive within endosomal compartments of monocytes and macrophages. Human mycobacteria! diseases include tuberculosis (caused by M. tuberculosis), leprosy (caused by M. leprae), Bairnsdale ulcers (caused by M. ulcerans), and various infections caused by M. marinum, M. kansasii, M. scrqfulaceum, M. szulgai, M. xenopi, M. fortuitum, M. chelonei, M. haemophilum and M. intracellular e. Wolinsky, E., Chapter 37 in Microbiology: Including Immunology and Molecular Genetics, 3rd Ed., Harper & Row, PhUadelphia, 1980, hereafter "Wolinksy"; Daniel, T.M. , MUler, R.A. and Freedman, S.D., Chapters 119, 120 and 121, respectively, in Harrison's Principles of Internal Medicine, 11th Ed., Braunwald, E., et al„ eds., McGraw-HiU, New York, 1987. One third of the world's population harbors M. tuberculosis (M. tb.) and is at risk for developing tuberculosis (TB), which is specifically responsible for 18.5% of deaths in adults aged 15 to 59. Bloom, B.R., and Murray, C.J.L.-, Science 257:1055-1064 (1992). Because improved public health and antibiotic therapy have greatly reduced the occurrence and/or severity of TB in the United States, these alarming statistics derive largely from third-world countries. Unfortunately, with the advent of AIDS, tuberculosis is increasing at a nearly logarithmic rate, and multidrug resistant strains are appearing and now account for one third of aU cases in New York City. Bloom, B.R., and Murray, C.J.L., Science 257:1055-1064 (1992); U.S. Congress, Office of Technology Assessment, The Cc tinuing Challenge of Tuberculosis, OTA-H-574, U.S. Government Printing Office, Washington, D.C., 1993. Mycobacterial strains which were previously considered to be nonpathogenic strains (e.g., M. avium) have now become major killers of immunosuppressed AIDS patients. Moreover, current Mycobacterial vaccines are either inadequate, in the case of the BCG vaccine to M . tb., or, with regard to M. leprae, unavailable. Kaufmann, S., Microbiol. Sci. 4:324-328 (1987); U.S. Congress, Office of Technology Assessment, The Continuing Challenge of Tuberculosis, ?.62-67, OTA-H-574, U.S. Government Printing Office, Washington, D.C., 1993. The major response to mycobacteria involves ceU mediated delayed hypersensitivity (DTH) reactions with T-cells and macrophages playing major roles in the intracellular kUling and containing or waUing off (granuloma formation) of the organism. A major T-ceU response involves CD4 + lymphocytes that recognize mycobacterial heat shock proteins (such as hsp65) as immunodoπύnant antigens. Kaufmann, S.H., et al., Eur. J. Immunol. 77:351-357 (1987). Leprosy Leprosy (Hansen's disease) is a chronic granulomatous infection of humans which attacks superficial tissues, especMy the sldn and peripheral nerves. Accounts of leprosy extend back to the eaxUestWΛorical records and document a stigmatization of leprosy patients which transcends cultural and reUgious boundaries. imtr, l A., Cb.^ 120 m Harrison's Pri ^ Internal Medicine, 11th Ed., Braunwald, E.. et al., eds.. McGraw-HiU. New York, 1987, hereafter "MiUer." In ancient times leprosy was rampant throughout most of the world, but for unknown reasons it died out in Europe in the sixteenth century and now occurs there only in a few isolated pockets. Wolinsky, p. 741. There are probably 10 to 20 million persons affected with leprosy in the world. The disease is more common in tropical countries, in many of which the prevalent rate is 1 to 2 percent of the population. A warm environment is not critical for transin-ssion, as leprosy also occurs in certain regions with cooler climates, such as Korea and central Mexico. Distribution of infected individuals within countries is very nonhomogeneous, and districts in which 20 percent of the population is affected can be found. MiUer, p. 633. In the United States, leprosy occurs particularly in Texas, California, Louisiana, Florida, New York City, and Hawaii, usually in persons originally from Puerto Rico, the PhUippines, Mexico, Cuba, or Samoa. Indigenous transmission occurs primarily in Hawaii, the Pacific Island territories, and specifically along the Gulf coast. Several hundred patients are cared for at the national leprosarium in CarviUe, Louisiana. Wolinsky, p. 741. Mycobacterium leprae, or Hansen's bacillus, is the causal agent of leprosy. It is an acid-fast rod assigned to the family Mycobacteriaceae on the basis of morphologic, biochemical, antigenic, and genetic similarities to other mycobacteria. M. leprae causes chronic graπulomatous lesions closely resembling those of tuberculosis, with epithelioid and giant-cells, but without caseation. The organisms in the lesions are predominantly intercellular and can evidently proliferate within macrophages, like tubercle bacttli. Wolinsky, p. 740. Although M. leprae has not been cultivated in artificial media or tissue culture, it can be consistently propagated in the foot pads of mice. Systemic infections with manifestations similar to those of human disease can be induced in aπnadiUos and mangabey monkeys. The baciUus multiplies exceedingly slowly, with an estimated optimal doubling time of 11 to 13 days during logarithmic growth in mouse foot pads. The mouse model has been used extensively for the study of antileprosy drugs, and the high bacterial yield from armadUlos has been crucial for immunogenic studies. MUler, p. 633. Leprosy is apparently transmitted when exudates of mucous membrane lesions and skin ulcers reach skin abrasions; it is not highly contagious and patients need not be isolated. Young chUdren appear to acquire the disease on briefer contact than adults. The incubation period is fsrimatftd to range from a few months to 30 years or more. Apparently, M. leprae can lie dormant in tissues for prolonged periods. Wolinsky, p. 741. Leprosy can present at any age, although cases in infants less than one year of age are extremely rare. The.age-specific incidence peaks during cWldhood in most developing countries, with up to 20% of cases occurring in chUdren under 10. Since leprosy is most prevalent in poorer socioeconomic groups, this may simply reflect the age distribution of the high-risk population. The sex ratio of leprosy presenting during chUdhood is essentially 1:1, but males predominate by a 2:1 ratio in adult cases. MiUer, p. 633. Leprosy is distinguished by its chronic, slow progress and by its mutilating and disfiguring lesions. These may be so distinctive that the diagnosis is apparent at a glance; or the clinical manifestations may be so subtle as to escape detection by any except the most experienced observers a med with a high index of suspicion. The organism has a predUection for skin and for nerve. In the cutaneous form of the disease, large, firm nodules Qepromas) are distributed widely, and on the face they create a characteristic leonine appearance. In the normal form, segments of peripheral nerves are involved, more or less at random, leading to localized patches of anestbesia. The loss of sensation in fingers and toes increases the frequency of minor trauma, leading to secondary infections and mutilating injuries. Both forms may be present in the same patient In either form of leprosy, three phases may be distinguished. (1) In the lepromatous or progressive type, the lesions contain many lepra cells: macrophages with a characteristicaUy foamy cytoplasm, in which acid-fast bacilti are abundant When these lesions are prominent, the lepromin test is usuaUy negative, presumably owing to desensitization by massive amounts of endogenous lepromin, and the ceU-mediated immune reactions to specific and nonspecific stimuli are markedly i m,inignerf The disease is then in a progressive phase and the prognosis is poor. (2) In the tuberculoid or healing phase of the disease, in contrast, the lesions contain few lepra cells and baciUi, fibrosis is prominent, and the lepromin test is usuaUy positive. (3) In the intermediate type of disease, bacilli are seen in areas of necrosis but are rare elsewhere, the skin test is positive, and the long-range outlook is fair. Shifts from one phase to another, with exacerbation and remission of the disease, are common. Hansen's bacillus may be widely distributed in the tissues of persons with leprosy, including the Uver and spleen. Nevertheless, no destructive lesions or disturbance of function are observed in these organs. Most deaths in leprous patients are due not to leprosy per se but to intercurrent infections with other microorganisms — often tuberculosis. Leprosy itself often causes death through the computation of amyloidosis, which is characterized by massive waxy deposits, containing abundant precipitates of fragments of immunoglobulin light chain in kidneys, liver, spleen, and other organs. Wolinsky, pp. 740-741. Bacteriologic diagnosis of leprosy is accomplished by demonstrating acid-fast baciUi in scrapings from ulcerated lesions, or in fluid expressed from superficial incisions over non-ulcerated lesions. No useful serologic test is available, but patients with leprosy frequently have a false-positive serologic test for syphilis. Also useful in the tuberculoid phase is the skin test with lepromin, an antigenic baciUary material prepared by boiling human lepromatous tissue or infected a midiUo tissues, which is typically standardized to contain 160 x 10 6 acid-fast bacilli/ml. Wolinsky, pp. 740-741. Therapy with dapsone (4,4'-diaπώτod_phenylsulfone) or related compounds usuaUy produces a gradual improvement over several years, and is continued for a prolonged period after apparent clinical remission. However, resistance to sulfonic drugs, with a concomittant relapse, may be noted after years of apparently successful treatment. Rifampin and clofazimine (B663, a phenozine derivative) are promising agents now under investigation for treating leprosy. Treatment results may be evaluated by counting the acid-fast baciUi in serial biopses and skin scrapings. Wolinsky, p. 741. Because of the neurodegenerative nature of leprosy, and associated symptoms, the management of leprosy involves a broad, _mι____isc_p___-_ry approach, including consulatative services such as orthopedic surgery, opthamology , and physical therapy in addition to antimicrobial chemotherapy. In any event, however, recovery from neurologic impairment is limited. MiUer, pp. 635-636. Summary of the Invention The present invention is based on the novel and unexpected observation that CDl molecules function to present foreign lipoarabinomannan (LAM) antigens to T-ceUs. The invention is further based on the observation that isolated blood monocytes can be induced to express CDl, and therefore become competent to present LAM antigens to T-ceUs, by contacting the monocytes with cytokines. Based on these two observations, the present invention discloses methods of isolating CDl + LAM antigen-presenting cells (CDl + APCs) which are used to identify, isolate, and purify CDl-presented LAM antigens, various methods for determining whether a sample contains one or more CDl-presented LAM antigens, methods for isolating and purifying CDl-presented LAM antigens, purified CDl-presented LAM antigens isolated by the methods disclosed herein, and methods of providing and using isolated CDl-presented LAM antigens in vaccines. In one embodiment, the present invention provides methods for determining whether a sample contains a CDl-presented LAM antigen. In one such method, the presence of a CDl-presented LAM antigen in the sample can be determined by (1) contacting the sample with cells which have been induced to express a CDl protein, (2) contacting the cells from the first step with T-ceUs that specificaUy recognize a CDl-presented LAM antigen, and (3) measuring the proliferative or cytolytic response of the T-cells, wherein increased T-ceU proliferation or T-ceU-mediated cytolysis of CD1 + target-cells, respectively, correlates with the presence of a CDl-presented LAM antigen. In a related embodiment, the present invention provides for methods of determining whether a sample contains a CDl blocking agent, Le. , a composition that inhibits CDl-restricted LAM antigen presentation. In the related embodiment, the assay for CDl-presented LAM antigen described above is performed in dupUcate, with a first (control) assay being performed as above, and a second assay additionaUy containing a sample suspected of containing a CDl blocking agent The presence of CDl blocking agents in the sample correlates with a T-ceU proliferative or cytolytic response in the second assay that is less than that measured in the first assay. The present invention further provides methods for inrinring CDl expression in cells, such as monocytes, in order to generate CD1 + LAM antigen-presenting cells (APCs). In one method, CDl expression is induced in isolated blood monocytes by contacting the cells with one or more cytokines. The preferred cytokines for CDl induction are granulocyte- macrophage colony stimulating factor (GM-CSF), GM-CSF in combination with interleukin-4 < L-4), or interleultin-3 (IL-3). CDl + APCs are cells that express and display CDl proteins and are thus competent to present CD- restricted antigens to TCR + T-cells. CD1 + APCs are used in several of the methods disclosed herein. The present invention further provides methods for isolating a CDl- presented LAM antigen from a sample. In one such method, a sample containing a CDl-presented LAM antigen is first fractionated using conventional techniques. The resulting fractions are then tested using known procedures, or those disclosed herein, for the presence of a CDl-presented LAM antigen. The fractions coiitaining the CDl-presented LAM antigen are then either used in the development of vaccines or are further fractionated to obtain higher levels of purity of the CDl-presented LAM antigen. The present invention further provides alternative methods for isolating CDl-presented LAM antigens from a sample which rely on the ability of a CDl-presented LAM antigen to bind either isolated CDl or CDl expressed on a ceU surface. In one such method, a sample ∞ntaining a CDl-presented LAM antigen is incubated with either CD1 + APCs or purified CDl molecules. The resulting complexes of LAM ___ύgen:CDl + APC or LAM antigeruCDl molecule are then removed from the sample and subjected to conditions in which the CDl molecule releases the bound CDl-presented LAM antigen. The released CDl-presented LAM antigen is then purified away from either the CD1 + APC or the purified CDl molecule and may be further characterized using conventional immunological, biochemical and/or genetic methods. Purified CDl-presented LAM antigens, or synthetic or genetically engineered derivatives thereof, are then tested for CDl-presented LAM antigen activity using known procedures, or those disclosed herein, and may be used in the formulation of vaccines. Utilizing the above procedures for isolating a CDl-presented LAM antigen, the present invention further provides isolated CDl-presented LAM antigens which have been prepared by the methods disclosed herein. The isolated CDl-presented LAM antigens prepared by the disclosed methods can be used either in the characterization of the nature of CDl-presented LAM antigens, in the development or formulation of vaccines and therapies. Brief Description of the Figures FIG. 1A-H show data for the expression of CDla, CDlb and CDlc by monocytes cultured with GM-CSF and IL-4, and surface phenotype of CDlb-restricted T-cells specific for Mycobacterium tuberculosis: Flow cytometric analysis of peripheral blood monocytes cultured for 60 hours in medium containing GM-CSF and IL-4 showing expression of CDla (FIG. 1A), CDlb (FIG. IB), CDlc (FIG. 1C), and HLA (FIG. ID). CeUs were stained with control monoclonal antibody (mAb) (dotted line) or mAbs with the specificity indicated in each histogram box (solid lines). Monocytes cultured in the absence of cytokines or with interferon-y did not express significant levels of CDla, CDlb or CDlc (data not shown). Flow cytometric analysis of T-ceU line DN1 showing its expression of cβ TCRs (FIG. IE), non-expression of CD4 (FIG. IF), and minimal or non-expression of CD8 (FIGS. IG, IH). Dotted and soUd lines represent control and specific mAbs as in FIGS. la-Id. FIG. 2A-E show data for antigen specificity and self restriction of proliferative responses of CD4"8" T-ceU line DN1 and its subclone DN1.C7. FIG. 2A shows data for the proliferative responses (counts per minute (CPM)) of 3 H-thymidine incorporated) of DN1 to M. tuberculosis (sotid squares), M. leprae (solid circles), Escherichia coli (open circles) and tetanus toxoid (open squares). Antigen presenting cells were heterologous GM-CSF- and Un¬ treated CD1 + monocytes. Antigen concentration (based on protein content) is shown on the x-axis. FIG. 2B shows data for the proliferative response of T-ceU line DN1 to M. tuberculosis (1 μg protein ml) requires CD1 + antigen presenting cells ( CD1 + APCs). APCs indicated by symbols as foUow: no APCs, open square; GM-CSF and IL-4 treated monocytes (CD1 + APCs), closed circles; IFNγ treated monocytes (CD1 + ), open circles; freshly isolated monocytes (CD1 + ), open triangles. The number of APCs added to each culture is shown on the x-axis. FIG. 2C shows data indicated that APC's from all donors tested supported the proliferative response of T-ceU line DN1 to M. tuberculosis. Open ban, T-cells plus APCs without M. tuberculosis; solid bars, T-cells plus APCs with M. tuberculosis (1 μg protein/ml). APCs were GM-CSF and IL-4 treated peripheral blood monoπuclear cells from five unrelated donors. HLA typing confirmed that no allele of the HLA-A, -B, - C.-DR. -DP or -DQ loci was shared among aU five donors (data not shown). FIGS. 2D, 2E show data indicating that anύ-CDlb mAb specifically inhibited the proliferative response of DN1 (FIG. 2D) and DN1.C7 (FIG. 2E) to M. tuberculosis (1 μg protein/ml). APCs were GM-CSF- and Untreated monocytes. SoUd bars, proliferative response of T-ceUs to APCs with M. tuberculosis (1 μg protein ml); dotted lines, response to APCs in the absence of if. tuberculosis,- "nd." not determined. Monoclonal antibodies used were P3 (control IgG), OKT6 (anti-CDla). WM-25 (anti-CDlb; Favaloro, EJ.. et al.,DiseaseMarkers4:261-2mi9SS>) . 10C3 (anti-CDlc). W6/32(ann-MHC Class I), and IVA12 (anti-MHC Class ϋ; Shaw. S., Hum. Immun. 72:191-211 (1985)). FIG. 3 show data for a comparison of the ability of antigen present i ng ceU lines CR1 and cytokine stimulated monocytes to stimulate growth of T- ceU lines 2.13.DN1 and G7, clones derived from T-ceU line DN1. Open bars, T-cellsplus APCs without/f. tuberculosis; solid bars, T-cells plus APCs with M. tuberculosis (1 μg protein/ml). HG. 4A-D show data for the presentation of M. tuberculosis by CDl trar^ecter^ofthe lymphobla-noidceUline ClR. C1R cells stably transfected with vector pSRα-NEO DNA (mock) or with constructs of pSRα-NEO containing cDNAs encoding the indicated CDl molecule (CDla, CDlb and CDlc) were cultured for 12 hours in medium alone (open bars) or in medium containing M. tuberculosis (25 μg protein ml. fiUed bars), labeled with 51 Cr and used as target-cells for cytolytic assay with various effector T-cells. The effector T-ceU to target-ceU ratio was 50:1. HG. 4A. shows for M. tb. CDlb-prcsented Ag-specific T-ceU line DNl. HG. 4B shows data for DN1 subclone DN1.C7. HG. 4C shows data for CDla autorcactive clone BK6. HG. 4D shows data for CDlc autoreactive done 3C8. HG. 5A-C shows data indicating that CDlb restricted presentation of M. tuberculosis antigen does not require MHC Class H region encoded molecules, but does involve antigen processing by a chloroquine sensitive pathway. HG. 5A shows data for lysis of (JD1 T2 transfecta j its by T-ceU line DN1. Tl cells transfected with vector DNA alone (mock transfectant) are indicated by circles, and T2 cells tramfected with CDlb by triangles. Open symbols represent target-cells not preincubated with M. tuberculosis, and fiUed symbols represent target-ceUs preincubated for 12 hours with M. tuberculosis (10 ug protein/ml). Flow cytometric analysis showed that incubation of CDlb transfected T2 cells with M. tuberculosis had no effect on CDlb expression (data not shown). HG. 5B shows data jr-tir^ting that glutaraldehyde fixation of CDlb 4" APCs prevents presentation of M. tuberculosis to line DN1. CDlb + APCs (GM-CSF- and _Lr4-treated peripheral blood mononudear cells, PBMCs) were cultured for 12 hours in the presence of if. tuberculosis (1 μg protein/ml; "Pulsed APCs") or in medium alone ("Uπpulsed APCs"), harvested and an atiquot of each ceU suspension was fixed with 0.0125% glutaraldehyde for 30 seconds. The resulting APC preparations were tested for their ability to stimulate proliferation of line DN1 in the absence (open bars) or presence (solid bars) of soluble Λf. tuberculosis antigen (1 μg protein/ml). HG. 5C shows data for inhibition of CDlb restricted presentation of M. tuberculosis by chloroquine. CDlb + APCs from an HLA- DR7 + individual were pulsed with M. tuberculosis antigen for 60 minutes at 37 β C in the presence of the indicated concentration of chloroquine, fixed with glutaraldehyde, and used as APCs in proliferative assays with line DN1 (soUd circles) or with the M. tuberculosis specific, HLA-DR7 + restricted CD4 + T- ceU line DG.l (open triangles). Results are expressed as percent inhibition of responses compared to fixed APCs pulsed with M. tuberculosis in the absence of chloroquine, and are representative of three similar experiments. FIG. 6 shows data indicating the effect on the proliferative response of T-ceU line DG.1 to if . tuberculosis antigen of digestion of antigen with the indicated proteases. HG. 7 shows data for the effect on the proliferative response of T-ceU line DN1 to M. tuberculosis antigen of digestion -of antigen with the indicated proteases. HG. 8 shows data for the effect on the proliferative response of T-ceU line DN1 to M. fortuitum antigen of digestion of antigen with the indicated proteases. FIG. 9A-C shows data indicating that a Mycobacterial antigen recognized by a DN a:β TCR + T^eU line quantitatively partitions into the organic phase after extraction with organic solvents and is CDlb restricted. Exttaction with organic solvents cUfferentiates the CDlb-restήcXcd Mycobacterial antigen from Mycobacterial antigens recognized by a conventional MHC class π restricted CD4+ a:β TCR+ T-cdl line and the small nonprotein Mycobacterial ligand recognized by DN r* (Vτ2Vδ2) TCR + T-cells. Pfeffer. K.. et at. J. Immunology 745:575-583 (1992). Total Mycobacterial sonicates were extracted with ddoroform/methanol/H 2 O and the resultant three phases were assayed by cult__ήng T-cells with CDl + monocytes and the indicated dUutions of the various antigen preparations. HG. 9A shows data for the proliferative response of the CDlb-restricted DN T-ceU line DN1 to total mycobacterial sonicates (-. dashed line), organic phase (D, soUd line), aqueous phase (O. soUd line) or interface (■. sotid line). Antigen concentration along the x axis is depicted as 1/dUution normalized to the standard total sonicate preparation. HG. 9B shows data for the proliferative response of the HLA-DR7 (MHC) restricted Mycobacterial specif i c CD4 + T-ceU line DG.l to Mycobacterial fractions after extraction with organic solvents. HG. 9C shows data for the proliferative response of the Vγ2V52 T-ceU clone DG.SF68 to Mycobacterial fractions after extraction with organic solvents. HG. 10 shows the cytolytic response of the DN1 line to CDl transfectants of ClR . ceUs pulsed with Mycobacterial antigen preparations. CDlb or CDlc transfectants (PorceUi, S., et at, Nature 547:447-450 (1989)) of ciRlymphoblastoid cells wereused as pulsed either with M. tuberculosis antigen preparations after extraction with organic solvents (+) or media alone (-). Recognition by the T-ceU line DN1 of C1R cells transfected with CDlb occurs only when pulsed with antigen. No antigen specific recognition occurs for CDlc + targets. πG . u shows the chemical structure of 6,6-trehalose di ycolate (cord factor). HG. 12A-E shows data indicating that the Mycobacterial antigen recognized by the CDlb-restricted T-ceU line DNl is mycoUc acid. HG. 12A, 12B show data indicating that the proliferative response of the CDlb- restricted T-ceU line DNl correlates with mycoUc acid peaks on reverse phase C18 HPLC. The purified Mycobacterial acyl chain fraction containing aU the CDlb-restricted antigen was cliromatographed using reverse phase HPLC and the resulting fractions assayed for the ability to stimulate a proliferative response by the T-ceU line DNl. HG. 12A shows data for display of the absorbance spectrum at 254 angstrom (expressed as optical density units, OD, x 10 *4 ) (soUd line) of the eluted material and the corresponding methylene chloride concentration (dotted line) of the elution gradient The large absorbance peak eluting between 2 to 6 minutes is free bromophenacyl bromide, the derivitiziπg agent. HG. 12B shows data for the proliferative response of the T-ceU line DNl to each one minute fraction. The CDlb- restricted antigen response is seen as a broad peak correlating with mycoUc acid. HG. 12C shows data indicating that saponified 6,6-trehalose dimycolate (cord factor), but not saponified trehalose dibehenate, stimulates a proliferative response by the CDlb restricted T-ceU line DNl. MycoUc acids were generated by saponification of purified trehalose dimycolate from either M. tuberculosis (H37Ra) or M. kansasii. Trehalose dibehenate (synthetic cord factor) was treated in an identical fashion. Antigen concentration is expressed in μg/ml of cord factor along the x axis. HG. 12D, 12E show data for the reversed phase HPLC analysis of purified trehalose dimycolate from M. tuberculosis (H37Ra) results in the stimulation of the CDlb-restricted T-ceU line DNl by fractions corresponding to mycoUc acid peaks. The saponified trehalose dimycolate of M. tuberculsis was chromatographed as in the experiment shown in HG. 12A (HG. 12D), and fractions assayed for the abiUty to induce a proliferative response by the line DNl (HG. 12E). As in HG. 12A, bioactivity correlates with early mycoUc acid peaks. HG. 13 shows data for the cytolytic response of the DNl T-ceU line to CD transfectants of C1R cells pulsed with mycoUc acid prepared from M. tb. cord factor (Sigma) by saponification. CDla, CDlb, CDlc or mock transfectants of C1R lymphoblastoid cells were pulsed with mycoUc acids prepared from trehalose dimycolate (+) or media alone (-) and used as targets in cytolytic assays, the results of which are given as % specific lysis. HG. 14A-C shows data indicating that mycoUc acid is not mitogenic, but a specific antigen restricted by CDlb and recognized by the T-ceU line DNl. Four T-cell lines specific for Mycobacteria and two additional T-cell lines were tested for the abiUty to respond to either total M. tuberculosis sonicates, mycoUc acid preparations from purified cord factor or HPLC purified mycoUc acids from either M. tb. sonicates or cord factor. The responses of three representative Mycobacterial specific T-ceU lines are shown, DNl (■) (DN, CDlb-restricted, a:β TCR + ), DG.l (D) (CD4 + , HLA-DR7 restricted, a:β TCR + ) and DN6 (O) (DN, CDlc-restricted, a:β TCR + . APCs for all six T-ceU Unes tested were identically GM-CSF- and IL-4-treated (CD1 + ) PBMCs from an HLA-DR7 positive individual. HG. 14A (upper panel) shows data for the proUferative responses of three Mycobacterial specific T-ceU lines to total sonicates of M. tb. (H37Ra, Sigma). Antigen concentration is displayed on the x axis as cpmx lO "3 . The three T-ceU lines shown all respond to total Mycobacterial sonicates. HG 14B (middle panel) shows data for the proliferative response to HPLC-purified mycolic acids isolated from if. tb. sonicates. Only the CDlb-restricted T-cell line DNl responds to purified mycoUc acid. HG. 14C (bottom panel) shows data for the proliferative responses to HPLC-purified mycolic acids generated from purified M. tb. cord factor (Sigma). Only the CDlb-restricted T-ceU Li__e DNl pro_υ:era_-s inrespo__« to cord factor mycoUc acids. Not shown are three additional T-ceU lines tested in the same esφeriment, SP-F3 (Roncarlo, M.G., et al. J. Exp. Medicine 765:2139-2152 (1988)) (CD4 + or.β TCR+, DR restricted, tetanus toxoid specific), CP.1.15 (Morita, C.T., et al., Eur. J. Immunol. 27:2999-3007 (1991)) (DN, Vγ2Vδ2 TCR + , Mycobacterial specific), BK6 (PorceUi, S., Nature 547:447-450 (1989) (DN, a:β TCR + , autoreactive to CDla). AU three did not respond to purified mycolic acids, but two proliferated in response to their specific antigen (tetanus toxoid - SP- F3, < 1 kDa M. tuberculosis preparation - CP.1.15). ' BK6 exhibits cytolytic activity against CDla, but is unable to proliferate in response to CDla + APCs of any type tested. PorceUi, S., Nature 547:447-450 (1989). HG. 15A-B shows data indinating the effect of the indicated monoclonal antibodies on the proliferative response of T-ceU line 2.13.DNl (HG. 15A) and 8.23.DN1 (HG. 15B). HG. 16A-D shows data for CDlc-restrieted presentation of M. tuberculosis antigen to T-ceU Une DN2. The results of cytolytic assays of CRl cells transfected with vector (mock, HG. 16A) and with DNA molecules encoding the indicated CDl protein (CDla, CDlb and CDlc) (HGS. 16B, 16C, 16D, respectively), wherein the transfected cells were either preincubated with (fiUed circles) or without (open circles) M. tuberculosis. HG. 17A-D shows data for CDlc-restricted presentation of M. tuberculosis antigen to T-ceU line DN6. The results of cytolytic assays of CRl cells transfected with vector (mock, FIG. 17A) and with DNA molecules encoding the indicated CDl protein (CDla, CDlb and CDlc) (HGS. 17B, 17C, 17D, respectively), wherein the transfected cells were either preincubated with (fiUed circles) or without (open circles) M. tuberculosis. HG. 18 shows data for the prliferative response of the CDlc-restricted ceU Une DN6 to M. tb. antigens in sonicates after extraction of the antigens with organic solvents. Proliferation is in cpm ( 3 H thymidine incorporation) displayed on the y axis. APCs were CDl expressing monocytes. Antigens were titered over 6 logs and the results from a representative point (1:3,750 dUution of antigen) are shown. Background cpm (defined from a media alone control) were subtracted from all values. HG. 19 shows data for the proliferative response of the CDlc- restricted ceU line DN6 to M. tb. antigens in sonicates before and after saponification of the antigens. Proliferative response in cpm is displayed on the y axis and the concentration of antigen (shown as 1/dUution) is displayed on the x axis. The equivalent of 10 mg of if. tb. (strain H37Ra; Difco) was sonicated in PBS and was either used directly or fust saponified. All antigen dUutions were normalized to the standard initial concentration of 200 mg lyophilized bacteria in 5 ml. HG 20A-B shows data indicating that DN a:β TCR + T-ceU lines from leprous skin lesions are CDl-restricted. HG. 20A (upper panel) shows data indicating that anti-CDlc mAb specificaUy inhibited the proUferative response of T-ceU Une LDN1 to M. leprae. HG. 20B (tower panel) shows data indicating that anti-CDlb mAb specificaUy inhibited the proliferative response of T-ceU Une LDN4 to M. leprae. HG. 21 shows <**1* for the proliferative response of T-ceU line LDN4 to the indicated ceUular fractions of if. leprae. HG. 22 shows the chemical structure of lipoarabinomannan (LAM). Abbreviations: Manp = mannopyranose; Araf = arabinofurnaose. HG. 23 shows data indicating that the T-ceU line LDN4 responds to LAM in a CDlb-restricted manner. HG. 24 shows data for the response of T-ceU line LDN4 to LAM derivatives. Abbreviations: dLAM * = dacylated LAM; PIM « phosphatidylinositol mannoside. HG. 25 shows data indicating that the T-ceU line BDN2 responds to LAM from if. leprae (Lep LAM) as weU as LAM from a clinical isolate of M. tuberculosis (TBE LAM) and a virulent laboratory strain of M. tuberculosis (Rv LAM). HG. 26A-B shows data for the flow cytometric analysis of OGD1 and OAB8 T-ceU lines. OGD1 T-cells were stained with biotin-conjugated anti-γδ TCR monoclonal antibody TCR51 or anti-Vδl monoclonal antibody 6TCS1 (revealed with PE-streptavidin), (HG. 26A). OAB8 T-cells were labdled with anti-αø TCR monoclonal antibody BMA031 (followed by PE- streptavidin), anti-CD4-FITC monoclonal antibody OKT4, anit-CD8-α-cl__in- FTTC monoclonal antibody OKT8 or anti-CD8-/5-chain-HTC 2ST8-5H7 (HG. 26B). HG. 27 shows data indicating that the TCR yδ* T-ceU line OGD1 responds to Mycobacterial antigens which partition in the organic phase of a chloroform/methanol extraction. For the organic fraction, whole PBS sonicates of Mycobacteria tuberculosis (DIFCO, Detroit, MI) (200 mg bacteria/5 ml PBS) were extracted (4:1, v/v organic to aqueous) with chloroform:methanol (2:1, v/v). Cord factor was obtained from SIGMA chemicals (St. Louis, MO). To prepare free mycoUc add, cord factor was saponified (25% KOH in methanol: H-0 1:1, 121 °C, 1 hr.) and mycoUc acids extracted into hexane. Preparations were dried with NO 2 and resuspended in media/fetal calf serum and tested at different dilutions in standard proliferation assay (50,000 activated monocytes with 50000 T-cells in a 3 day assay). HG. 28 shows data indicating that the TCR yδ + T-ceU Une OGD1 is restricted by CDlb, as demonstrated by cytotoxic assays of the TCR yδ + T- cell line on antigen pulsed activated monocytes. To prepare target cells, the monocytes were incubated overnight with no antigen (open boxes) or the organic fraction (fiUed boxes). Target cells were then labelled with "Cr and T-cells were added to the target cells at a ratio of 10: 1 with different blocking antibody (no monoclonal antibodies, anti-MHC I (BB7.7)), mixture of all anti- CD 1 monoclonal antibodies, anti-CDla (OKT6), anti-CDlb (WM25) or anti- CDlc (10C3)). The measurement of the cytotoxicity was calculated as in standard cytotoxic assays, Le., specific cytolys_s=(Expe__menl_J.- Spontaneous)/(M_--imum-Spon-ai_-ous) X 100. HG. 29 shows data indicating that the CD8 + ctβ + T-cell line OAB8 responds to Mycobacterial mycolic acid. MycoUc add was purified by HPLC from M. tb. (prepared as described in Example 4) and used at 1 μg/πύ. Control antigens are Diphtheria toxoid (available-from Dr. R. Finberg, Dana Farber Cancer Institute, Boston, used at 10 μg ml) and M. tb. LAM (as in Example 8; 1 μg ml). Fractions were resuspended in media/fetal calf serum and tested as described in HG. 27. FIG. 30 shows data indicating that the CD8 + aβ* T-ceU line OAB8 is restricted by CDlc, as demonstrated by proliferation assays performed as in HG. 27. Monoclonal antibodies were added to the culture at a 1/200 final dilution of ascites. Antigens are as described in HG. 29 and antibodies are the same as in HG. 28. Description of the .Preferred Embodiments Glossary Antigen: A molecule, compound or composition of matter which (1) induces an immune response in an animal, alone or in combination with an adjuvant; and (2) interacts specificaUy with one or more antigen-recognizing components of the animal's immune system. Foreign antigen: An antigen which is not endogenous to a normal, healthy animal. Autoimmune antigen: An endogenous molecule, compound or composition of matter in an animal which comprises an antigen in an autoimmune disease. This term is synonymous with "self antigen" and "autoantigen." CDl-presented antigen: An antigen which is bound by a member of the CD 1 family of proteins and displayed on the surface of an CD 1 + APC . CDl-presented antigens vary in their size and composition depending on their origin and the member of CDl famU that they are recognized by. As used herein, the term "CDl-presented antigen" includes those antigens identified herein and/or those antigens isolated using the known procedures or those disclosed herein. This term is synonymous with "CDl-restricted antigen." "CDl-bound antigen" designates a CDl-presented antigen that is bound to its appropriate CDl molecule. LAM antigen refers to antigens comprising at least one lipoarabmomannan (LAM>-or a derivative thereof. CDl family of proteins: A collection of proteins which have been identified by their structure, immunologic cross-reactivity and/or distribution, 4 -29- as being related to known CDl molecules. A specific CDl protein may be referred to as a member of the CDl family of proteins. Members of the CDl family of proteins include, but are not limited to, CDla, CDlb, CDlc, CDld and CDle (see, PorceUi, S., et al., Immun. Rev. 720:137-183 (1991)). CDl positive cell: A ceU which expresses and displays one or more members of the CDl family of proteins. This term is synonymous with "CDl + ceU." One skiUed in the art can use the procedures described herein, or known in the art, for determining whether a ceU is expressing one or more members of the CDl family of proteins (see Example 1 and PorceUi, S., Immun. Rev. 720:137-183 (1991)). Antigen-presenting cell (APQ: An APC includes any ceU which displays antigen molecules on its surface via protein carriers and which presents antigen to T-cells. Antigen-binding protein carriers include MHC class I molecules, MHC class π molecules and CDl molecules; corresponding APCs are designated MHC I + APCs, MHC H + APCs and CDl + APCs. CDl-restricted T-cell: A mature TCR positive (TCR + ) T-cell which can recognize a CDl-bound CDl-presented antigen. CDl-restricted T-cells include any subset of T-cells which interact with a CDl-bound CDl-presented antigen. CD4~8~ T-cell: A mature TCR + T-ceU which does not express CD4 and CD8. This term is synonymous with "double negative T-ceU" and "DN T-ceU. * Techniques for identifying CD4~8~ T-ceUs are weU known in the art and can readfly be employed in the present invention, for example using flow cytometry as described in Example 1, and/or in Panchomoorthy, G., et al, J. Immuno. 747:3360-3369 (1991)). Using such procedures, time CD4~8~ T-ceU lines, designated DNl, DN2 and DN6, have been isolated and are described herein. Adjuvant: A molecule, compound or composition of matter which, when introduced into an animal with an antigen, enhances one or more immtme responses to that antigen. -30- Genetic engineering: This term refers to any human manipulation intended to introduce genetic change. Sample: Any solution, emulsion, suspension, or extract which can be tested using known procedures, or those disdosed herein. A sample may be, but is not limited to. a soluble extract or an organic extract. E∞ples I and 2 provide various non-limiting types of samples derived from Mycobacterium tuberculosis. Contacting: The process of incubating or placing in proximity one item with another. For example, when a ceU is contacted with a sample, the ceU is incubated with the sample. Fractionating: Subjecting a sample to conditions or procedures which separate the components of the sample based on physical or chemical properties such as, but not limited to, size, charge, solubility, or composition. Examples of fractionation procedures include, but are not limited to, selective precipitation, organic extraction, size exclusion dialysis or chromatography, and ion exchange chromatography. Expressing: The process ofproducing a product involving transcription of a DNA molecule to generate a corresponding mRNA molecule that is optionaUy translated into a polypeptide by ribosomes and associated ceUular factors. Displaying: The process of localizing a protein, or a proteimantigen complex, .to the outermost surface -of a ceU where the protein or protei antigen complex is accessible to a second ceU or to molecules displayed by a second ceU. A protein, or a protein-antigen complex, is said to be displayed by a ceU when it is present on the outermost surface of the c l and is thus accessible to a second ceU and/or to molecules displayed by a second ceU. Processing of antigen: The process by which an antigen is treated by ceUular factors in order to be made competent for displaying. CD7 blocking agent: A composition or compound which is capable of blocking the interaction of a CDl-presented antigen with CDl. or of blocking the interaction between CDl:antigen complexes and their cognate T-cell receptors. Blocking agents include (1) agents which bind to CDl, (2) agents which bind to a CDl-presented antigen, (3) agents which bind to a CDl:antigen complex, (4) agents which bind to a T-ceU receptor that recognizes a CDl:antigen complex and (5) agents which prevent the processing of a CDl-presented antigen. The Present Invention The present invention is based on the unexpected observation that CDl molecules function to present LAM antigens to T-ceUs. The invention is further based on the observation that cells can be induced to express CDl , and therefore become competent to present antigens to T-ceUs. Such presentation can involve contacting the cells with cytokines such as, but not li itwri to, granulocyte macrophage colony stimulatingfactor (GM-CSF) and interleukin-4 (LL-4). Based on these two observations, the present invention comprises: - methods for detecting the presence of a CDl-presented LAM antigen in a sample; - methods for isolating such CDl-presented antigens and the isolated antigens; - vaccines containing CDl-presented antigens and vaccination methods; - methods of blocking CDl antigen presentation; - methods of identifying and/or isolating CDl blocking agents and the isolated CDl blocking agents; - methods of inducing CDl expressionrand - T-cells for use in the methods disclosed herein. In one embodiment, the present invention provides methods for determining whether a sample contains a CDl-presented antigen. In one such method, the presence of a CDl-presented antigen in a sample can be determined by: first, contacting the sample with a CDl positive cell; second, contacting the ceU of the first step with a T-ceU; and third, measuring the proliferation of the T-ceU. Methods of characterizing classes of T-cells, and of isolating subpopulations of T-ceUs, are known. See, e.g., Wysocki, L.J., and Sato, V.L., Proc. Natl. Acad Sci. (USA) 75:2844-2848 (1978); Wasik, M.A., and Morimoto, C, J. Immunol. 744:3334-3340 (1990); Ha man. G.R., et oL, J. Immunol. 745:4206-2414 (1990); Koulova, L., et al., J. ImmunoL 745:2035-2043 (1990); Steward, M., and Male. D., Chapter 25 in Immunology, 2d Ed., Roitt, I., et al., eds., Gower Medical Publishing, London, New York, 1989. Methods of culturing T-cells in vitro, and of immortalizing T-cells via fusion to non-growth restricted cells such as myelomas, are also known. See, e.g., Paul, W.E., et al.. Nature 294:697-699 (1981); Williams, N., Nature 296:605-606 (1982). Techniques for identifying T-cells subsets that are reactive with CDl presented antigens are also known in the art and can readily be employed in the present invention, for example using flow cytometry as described in the Examples and/or by known techniques such as those descibed in Panchomoorthy, G., et al., J. Immuno. 747:3360-3369 (1991)). The present invention advances these techniques by providing methods for enriching T-ceU populations to obtain isolated T-ceU clones which are reactive to CDl- presented antigens. For example, a population of T-cells is allowed to divide and a subpopulaύon of mixed T-cells is isolated based on proliferation in the presence of CDl * APCs and CDl-presented antigen, or on cytolytic activity against transfected cells expressing CDl molecules in the presence of a CDl- presented antigen. Using such procedures, non-limiting examples of such CDl reactive T-ceU subsets have been identified, including CD4~8 " T-ceU Unes, CD8 + TCR aβ* T-ceU lines, and TCR yδ* T-ceU lines. The present invention further provides methods for inducing CDl expression on a ceU. In one such method, a ceU can be induced to express CDl by contacting the ceU with one or more cytokines, as known in the art. 5/13274 -33- The preferred cytokines for CDl induction are granulocyte/macrophage colony stimulating factor (GM-CSF), GM-CSF in combination with intorleukin-4 (IL- 4), or interleukin-3 (IL-3). Example 1 discloses that monocytes can be induced to express various members of the CDl family by contacting the monocyte with 100 units each of GM-CSF and IL-4 for 60 hours in RPMI- 1640 supplemented with 10%. fetal calf serum. Using the methods and materials disclosed herein, one skilled in the art can readily vary the contacting time, cytokine type, cytokine concentration, and contacting conditions to obtain favorable results so long as the contacting step is sufficient to induce CDl expression. Several procedures are known in the art for determining the proliferation of T-cells and can be used in the above methods. One skilled in the art can readily adapt such procedures for use in the present invention. One such procedure, described in Example 1, measures the rate of incorporation of 3 H-thymidine via Uquid scintillation and by methods described in Morita, C.T., et al, .Eur. J. Immunol. 27:2999-3007 (1991)). The present invention further provides methods for isolating a CDl- presented antigen from a sample. In one such method, a sample is first fractionated using conventional procedures. The fractions of the sample are then tested for the presence of a CDl-presented antigen as outlined above. Examples 2 and 3 describes fractionation procedures using organic extraction with chlorofoπn:methanol and silicic acid chromatography to fractionate a sample containing an extract of M. tuberculosis to purify a CDl-presented antigen. The present invention further provides methods for isolating a CDl- presented antigen which rely on the specificity of binding of CDl to a CDl- presented antigen. In one such method, a sample containing a CDl-presented antigen is first contacted with either purified CDl, or a ceU which expresses and displays CDl (a "CD1 + cell"). The resulting antige CDl complex, or antigemCDl " ceU complex; is then separated from the sample. Using such a procedure, a purified antige CDl complex or antigen:CDl + ceU complex -34- is obtained. To further purify d> CDl-presenied antigen, either type of complex is treated under >W ~~ -*•"» ■ "* " * " " * » CMΛnΛ antigen will be released from the CDl mo-eu-- Tte above two isoUdon -_-< «■ be combined by the -dual artisan to derive other π-tbods for _ol__« CD1-I«c^ «**β« s - » •» ι »«__.. _* » -*-* , " -, '**' te ' p rforming a purification method which relies on the binding of . CDl- presented antigen to CDl. The present invention further provides CDl-presented antigens which are identified or isolated using known procedures, or those disclosed herein. Unlike MHC-presented antigens. CDl-presented antigens are not l i m i ted to polypeptides. One CDl-presented nonpeptide antigen, described in deta i l m Examples 2- , is a lipid antigen isolated from M. tuberculosis that comprises mycolic acids. Another CDl-presented antigen from M. tuberculos i s, described in Examples 5 and 6. is a more complex lipid. A CDl-presented antigen from M. leprae is lipoarabmomannan (LAM), described in Examples 7-9. CDl-presented antigens are hydrophobic and have use in vaccine formulation and development. The CDl-presented LAM antigens of the present invention, Le., those identified or isolated using known procedures, or those disclosed herein, are rea-tily usable as vaccines. A skffled artisan can employ routine formulation procedures in order to formulate an isolated CDl^resented antigen for use as a vaccine. In addition to the CD-I presented antigen in such vaccines, the vaccine can further comprise at least one additional CD-I molecule or at least one MHC-I or MHC-H presented antigen. See. e.g.. Remington's PharmaceuticalSάences, ISthEd.. Gennaro, A.R., ed. t Mack. Easton, 1990; The Pharmacologist Basis of Therapeutics, 7th Ed.. Oilman. A.G.. et al., eds.. MacMiUian, New York, 1985; Avery's Drug Treatment: Prinάplesand PracticeofOimWPharmacologyandTte 3rd edition. ADIS Press, Ltd.. WUliams and Wilkins, Baltimore, MD (1987). The CDl-presented antigens of the present invention can be purified as disclosed herein over a wide range of purities. A skiUed artisan wiU know how to employ various purification strategies in order to obtain a CDl- presented antigen which has been purified to the extent required for an intended use. The vaccines of the present invention can be formulated using a purified CDl-presented antigen or can be formulated using a CDl-bound antigen. Because CDl-restricted antigens are presented to T-ceUs as a complex of antigen and CDl, the use of an antigemCDl complex can, in some cases, provide superior immunization properties. -36- The CDl-presented antigens of the present invention can be administered to vertebrate animals, including mammals. The vaccines of this invention wiU have both human and veterinary appUcations as prophylactic and therapeutic vaccines. Further, when used therapeuticaUy, these vaccines can be combined with chemotherapy to produce a more effective treatment of many diseases. The antigenic materials can be employed in admixture with conventional excipients; i.e., pharmaceuticaUy acceptable organic or inorganic carriers which do not deleteriously react with the immunologicaUy-acύve components and which are suitable for parenteral, mucosal, or even topical applications. Such a carrier includes but is not limited to saline, buffered saline, dextrose, water, glycerol, ethanol, oils, and combinations thereof. The carrier and composition can be sterile. The formulation should suit the mode of administration. Parenteral administration can include the introduction of substances into an organism by intravenous, subcutaneous or intramuscular means, including by implant. Mucosal administration includes pulmonary, intranasal, oral, vaginal, or rectal administration. The carrier can be added to the vaccine at any convenient time. In the case of a lyophUized vaccine, the carrier can, for example, be added immediately prior to administration. Alternatively, the final product can be manufactured with the carrier. The present invention provides a variety of pharmaceutical compositions. Such compositions comprise a therapeuticaUy (or prophylacticaUy) effective amount of an antigen or a CDl:antigen complex, and a carrier. The composition, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents, or preservatives. Typical preservatives can include, potassium sorbate, sodium metabisulfite, methyl paraben, propyl paraben, thimerosal, etc. The composition can be a Uquid solution, suspension, emulsion, tablet, piU, capsule, sustained release formulation, or powder. The method of administration can dictate how the composition wiU be formulated. For example, the composition can be formulated as a suppository, with traditional binders and -37- carriers such as triglycerides. Oral formulation can include plant materials, Haq, T.A., et al.. Science 268; 714-716 (1995), or standard carriers such as pharmaceutical grades of mannitol, lactose, starch, magnesium stearate, sodium saccharine, ceUulose, magnesium carbonate, etc. A variety of adjuvants can also be used to amplify ceU-mediated and humoral responses when mixed with a CDl-presented antigen. The adjuvant of choice for human administration is an aluminum salt such as alum, aluminum hydroxide or aluminum phosphate. Other adjuvants, for example, oU-based emulsions that contain biodegradable materials, can be tested in combination with the antigen and found to be effective and safe. Adjuvants that are oU-based emulsions include Syntex formulation SAF-1, Ciba-Geigy formulations, and Ribi formulation. See, Rabinovich, N.R. et al, Science 265:1401-1404 (1994). Freund's incomplete or complete adjuvants can also be effective. Methods of administration wiU vary in accordance with the type of disorder and microorganism sought to be controUed or eradicated. The dosage of the vaccine will be dependent upon the amount of antigen, it's level of antigenicity, and the route of administration. A person of ordinary skiU in the art can easUy and readUy titrate the dosage for an immunogenic response for each antigen and method of administration. For parenteral application, particularly suitable are injectable, sterile solutions, preferably oUy or aqueous solutions, as weU as suspensions, emulsions, or implants, including suppositories. For enteral or mucosal appUcaύon (including via oral and nasal mucosa), particularly suitable are tablets, tiquids, drops, suppositories or capsules. A syrup, elixir or the like can be used wherein a sweetened vehicle is employed. Topical application can also be used for example, in intraocular administration. Alternative methods of administration can include an immune-stimulating complex (ISCOM) as described in U.S. patent No. 4,900,549 (or European Patent PubUcation No. 0 604727 Al (Publ. July 6, 1994). In addition, viral vectors, Uposome and microspheres, and microcapsules are avaUable and can be used. See, Rabinovich, supra. For diseases of the lungs, such as tuberculosis, pulmonary administration may be preferred for prophylactic purposes or for immediate and specific localized - - treatment. Pulmonary administration can be accomplished, for example, using any of various delivery devices know in the an. See. «.... Newman, S.P. (1984) ιn Aerosols and ,he Lung. Clarke and Davia (eds.), Bunerwonhs. -ondon, England, pp 197-224; PCT Publication No. WO 92/16192; PCT Publication No. WO 91/08760; NTIS Patent Application 7,504,047 (1990), including but not lim i ted to nebulizers, metered dose inhalers, and powder inhalers. Various delivery devices are commercially available and can be employed. e.g., -_ W -» nebul i zer (Mallinckrodt. Inc.. St. Louis. Missouri); Acorn π nebulizer (Marquest Medical Produc-. Englewood, CO). Such devices typically entail the use of formulations suitable for dispersing from such a device, in which a propcllant material may be present. The discovery that LAM or its derivatives eUcit T-ccU proliferation extends the spectrum of antigens presented by CDl molecules and provides the opportunity for vaccines comprising CDl-presented antigens that are effective against all gram negative and most gram positive bacteria (including Streptococcus sp. and Staphylococcus sp.), and a variety of parasitic protozoa. AU gram negative bacteria contain lipopolysaccharides (LPS) which are similar in structure to lipomannans. Most gram positive bacteria contain structurally-related glycolipids such as lipoteichoic acids. In addition, the chemical composition of many disease- causing protozoa includes LAM-like glycolipids such as the lipophosphoglycans of Leishmania. Orlandi. P. A. and S.J. T rco. J. Biol. Chem. 262:10384-10391. It is likely that the cell walls and other cellular components of the fungi also conta i n lipoglycans; therefore, vaccines comprising CDl-presented antigens can be used to prevent or treat fungal infections of vertebrates. These antigens wiU include LAM, its derivatives, or its functional equivalent in microbial organisms, whether prokaryotic or eukaryotic in nature. At present, vaccines against protozoan parasites are either nonexistent or not feasible for mass immunization. See, e.g., Nussenzweig. R.S. and CA. l_ong, Science 265:1381-1383 (1994). Examples of diseases caused by protozoa include, but are not limited to, malaria, trichinosis, filariasis, trypanosomiasis, schistosomiasis, toxoplasmosis and leishmaniasis. Protozoan infections can be more difficult to control and eradicate than bacterial infections because compounds that kill a protozoan parasite are often toxic to the host. For example, most of the drugs used to treat diseases caused by Trypanosoma species can cause serious side effects and even death. In addition, drug resistance of many protozoal species is becoming increasingly common in most parts of the world. The presence of glycoUpids in protozoa opens the door to a whole new class of vaccines based on the T-ceU proliferation to a CDl-presented hydrophobic antigen. Vaccines incorporating glycolipids or glycolipid derivatives either by themselves or combined with a protein antigen could prove an efficacious and cost-effective treatment against protozoan parasites. An advantage of such a vaccine is that toxic medicaments may sot have to be _ _____tistered or can be administered in reduced dosages in conjunction with a CDl-presented antigen to control the infection. The present invention further provides methods for assaying for inhibitors of CDl-restricted antigen presentation to T-ceUs, Le., CDl blocking agents. In one such method, CDl antigen presentation is inhibited by using a CDl blocking agent to block the abiUty of a CDl-restricted antigen to bind to CDl. As used herein, a CDl blocking agent is said to "inhibit CDl- restricted antigen presentation" when the CDl blocking agent decreases (1) the binding of a CDl-presented antigen to a CDl molecule or (2) the binding of a CDLCDl-presented antigen complex to its cognate T-ceU receptors. Some CDl blocking agents are able to block such binding to undetectable levels while other CDl blocking agents only sUghtly decrease such binding. CDl blocking agents include, but are not limited to, (1) agents which bind to CDl, (2) agents which bind to the CDl-presented antigen, (3) agents which bind to the CDl:antigen complex, and (4) agents which bind to the T-cell receptors that recognize the CDl:antigen complex. Respective examples of blocking agents include, but are not limited to, (1) polyclonal or monoclonal antibodies which bind to and block the portion of a CDl molecule that binds a CDl- presented antigen, (2) polyclonal or monoclonal ___tibod.es which bind to and block the portion of a CDl-presented antigen that binds CDl, (3) synthetic oUgopeptides that are derived from the CDl .-antigen-binding portion of a T- ceU receptor and which bind to and block the portion of the CDl .-antigen complex bound by intact T-ceU receptors, and .(4) synthetic compounds comprising a CDl-presented antigen chemically linked to a purified CDl molecule or a synthetic derivative thereof. In an alternative method for inhibiting antigen presentation of CDl- restricted antigens, a CDl blocking agent can be employed -which blocks the interaction of the antigen:CDl complex with the TCR molecules on the T-cdl. By inhibiting the presentation step, the activation of specific subsets of T-cells can be inhibited. PUot trials are currently underway of treatment of humans suffering from an autoimmune disease with peptides derived from TCR molecules. Oksenberg, J.R., et al., J. Neurol. Sci. 115 (Suppl.):S29-S31 (1993). DNA molecules encoding TCR polypeptides displayed by T-cells that recognize the CDl-presented antigens of the invention are isolated according to methods known in the art. Oskenberg, J.R., et al., Proc. Natl. Acad. Sci. (USA) 56:988-992 (1989); Oksenberg, J.R., etal.. Nature 345:344-346 (1990) and erratum, Nature 353:94 (1991); Uematsu, Y., et al.. Proc. Natl. Acad. Sci. (USA) 85:534-538 (1991); Panzara, M.A., et al., Biotechniques 72:728- 735 (1992); Uematsu, Y., Immunogenet. 34:174-178 (1991). The DNA sequence is converted into a polypeptide sequence, and the portion of the polypeptide sequence that corresponds to the antigen-binding variable region of a TCR polypeptide is used to design synthetic oUgopeptides that bind CDl:antigen complexes on APCs, thereby inhibiting antigen presentation. OUgopeptides are chemically synthesized according to standard methods (Stewart and Young, Solid Phase Peptide Synthesis, Pierce Chemical Co., Rockland, Illinois, 1985) and purified from reaction mixtures by reversed phase high pressure Uquid chromatography (HPLC). AdditionaUy or alternatively, methods for generating anti-TCR antibodies and anti-TCR binding peptides are weU known in the art with regard to MHC presentation and can readUy be adapted to the herein disclosed CDl presentation system. Strominger, J.L., CeU 57:895-898 (1989); Davis, M.M., and Bjorkman, P.J., Nature 534:395-404 (1989). A skilled artisan can readily employ known methods of antibody generation, as well as rational blocking agent design in order to obtain the blocking agents of the present invention. Harlow, E., and Lane, D., Antibodies: A Laboratory Manual, Cold Spring Harbor Press, Cold Spring Harbor, 1988; Synthetic Peptides: Answers Guide. Freeman, W.H., New York, 1991; Kasprzak, A. A., Biochemistry 25:9230-9238 (1989). AdditionaUy or alternatively, libraries of molecularly diverse molecules can be screened for individual member molecules which are CDl blocking agents. Effective CDl blocking agents are identified by their ability to inhibit CD1- mediated T-ceU proliferative and/or cytolytic responses using the materials and methods described herein. The embodiments of the invention described above can be used for the indicated purposes, alone or in combination with each other or other complementary methods and/or compositions. The manner and method of carrying out the present invention may be more fully understood by those of skill by reference to the following examples, which examples are not intended in any matter to limit the scope of the present invention or of the claims directed thereto. Example 1: Antigen Presentation by CDlb Methods How cytometry was performed as described previously (Panchamoorthy, G., et al., J. Immunology 747:3360-3369 (1991)) using the foUowing monoclonal antibodies (mAbs): P3 (IgGl control; Panchamoorthy, G., et al., J. Immunology 747:3360-3369 (1991)), OKT6 (anti-CDla; Reinherz, E., et al., Proc. Natl Acad. Sci. (USA) 77:1588-1592 (1980)), 4A7.6 (anti-CDlb; OUve, D., et al., Immunogenetics 20:253-264 (1984)), 10C3 (anti-CDlc; Martin, L.H., et al., Proc. Natl. Acad. Sci. (USA) 54:9189- 9193 (1987)), W6/32 (anti-HLA-A,B,C; Brodsky, P.M., and Paiham, P.P., -42- J. Immunology 728:129-135 (1982)), BMA031 (anti-α TCR; Lanier, L.L., et al, in Leukocyte Typing III, McMichael, A.J., ed., pp. 175-178, Oxford University Press, 1987), 0KT4 (anti-CD4; Reinherz, E., et al., Proc. Natl. Acad. Sci. (USA) 77:1588-1592 (1980)), OKT8 (anti-CD8or, Reinherz. E.. et al, Proc. Natl. Acad. Sci. (USA) 77:1588-1592 (1980)) and 2ST8-5H7 (anti-CDδβ; Shiue, L., etal., J. Exp. Med. 768:1993-2005 (1988)). Monocytes were isolated from leukocyte concentrates of normal donors by plastic adherence (Anegon, I., etal, J. Immunology 747:3973-3980 (1991)), and detached by incubation at 37 β C in phosphate buffered saline (PBS) with 0.53 mM EDTA (PBS/EDTA). Adherent-ceils were typicaUy > 90% CD14 + and MHC class ϋ + , and negative for CDla, CDlb and CDlc as determined by surface staining (data not shown). To induce CDl expression, monocytes were cultured for 60 hours in RPMI-1640 (Gibco) containing 10% fetal calf serum (FCS, Hyclone) with 100 Units/ml each of GM-CSF and IL-4 (Genetics Research Institute). CeUs were harvested using PBS/EDTA as above. T-ceU line DNl was established from a random normal donor's peripheral blood. Nonadherent mononu ear cells were treated with mAbs 0KT4 and OKT8 and rabbit complement, and the remaining viable cells were suspended in a mixture of 0KT4 (anti-CD4), 0KT8 (anti-CD8α) and anti- TCRόl (PorceUi, S., et al., Immun. Rev. 720:137-183 (1991)) mAbs for 1 hour, washed and incubated for 30 minutes at 4°C with goat anti-mouse immunoglobulin coupled magnetic beads (Dynal). After magnetic separation and removal of CD4 + and/or CD8 + and/or δ-TCR cells, the remaining CD4"8~ :β TCR 4" cells were cultured with equal numbers of autologous monocytes in complete medium (RPM-1640 with 10% FCS and additional supplements as previously described by Morita, C.T., et al. (Ear. J. Immun. 27:2999-3007 (1991)) with 100 U/ml each of GM-CSF and H_-4. M. tuberculosis soluble extract, produced by sonication of desiccated bacUli (strain H37Ra (Difco)) in PBS foUowed by centrifugation at 100,000 g to clarify (i.e., to remove insoluble material from) the sonicates, was added to a bacterial protein concentration of 10 μg/ml. More soluble antigenic (i.e., T-ceU proUferative) activity is obtained from soluble aqueous sonicates of if. tb. by adding detergents such as CHAPS or octylglucoside during the sonication step; without addition of detergent, 90 to 95% of antigenic activity is lost during post-sonification clarification. Cultures were restimulated every 10 to 14 days with M. tuberculosis and heterologous CDl 4" monocytes (induced to express CDl as described above) in complete medium, and were fed every three to four days with fresh medium containing 1 nM recombinant interleukin-2 (IL-2). T-cell proliferation response assays were carried out in triplicate with 5 x 10 4 each of T-ceUs and irradiated (5,000 Rad) APCs in 200 μl complete medium in 96 weU flat bottom microtiter plates (Linbro). M. leprae and Escherichia coli soluble extracts were produced as described for M. tuberculosis. Monoclonal antibodies were added as purified immunoglobulin to a final concentration of 25 μg/ml. Cultures were harvested on day five (day three for mAb blocking) after a six hour pulse with 1 μCi 3 H-thymidine (6.7 Ci mmol, New England Nuclear), and 3 H incorporation determined by liquid scintillation counting. Results are expressed as the mean counts per minute (CPM) of 3 H-thymidine incorporation of tripUcate cultures. Isolated monocytes or whole peripheral blood mononudear cells (PBMCs) were treated with recombinant GM-CSF and IL-4 as above, or with IFNy 100 U/ml for 60 hours pripr to combining them with T-ceUs for proliferation assays. T-ceU clone DN1.C7 is representative of four extensively characterized subclones derived from DNl by phytohemagglutinin (PHA) stimulation in limiting dUution culture and propagated using PHA stimulation and IL-2 as previously described. Morita, C.T., et al., Ear. J. Immun. 27:2999-3007 (1991). AU clones derived from line DNl had a surface phenotype indistinguishable from that shown in Fig. lb, i.e., :β TCR expression, non-expression of CD4, and minimal or non-expression of CD8. T-ceU cytolytic response assays were carried out as foUows. Methods of transfecting C1R cells and assaying specific cytolytic activity by 51 Cr release have been described. Balk, S.P., et al, Science 253:1411-1415 (1991) and Morita, C.T., et al., Eur. J. Immun. _?7_2999-3007 (1991), respectively. BK6, an a:β TCR cytotoxic T-ceU clone that lyses cells displaying CDla, was isolated from the blood of a patient with SLE as previously described (PorceUi, S., et al, Nature 347:447-450 (1989)), and clone 3C8, an or.β TCR cytotoxic T-cell done that lyses cells displaying CDlc, was isolated from the blood of a normal donor using the same method. Transfected cells were labeled with 51 Cr and used as target-cells in cytolytic assays with an effector (T-ceU) to target (transfectant) ratio of about 50:1. Methods of assaying 51 Cr release and calculating the % specific lysis have been described. Brenner, M.B., et al.. Nature 325:689-694 (1987). Stable transfectants of T2 cells were prepared using the method described for C1R cells. Balk, S.P., et al.. Science 253:1411-1415 (1991). APCs for glutaraldehyde fixation and chloroquine experiments were GM-CSF- and H_-4-treated PBMCs as described above, and glutaraldehyde fixation and chloroquine treatment of APCs were performed according to published methods. Chesnut, R.W., et al., J. Immun. 729:2382-2388 (1982); Roncarolo, M.G., et al, J. Immunol. 747:781-787 (1991). CD4 + T-ceUUne DG.l was derived from an HLA-DR7 4* rheumatoid arthritis patient by repeated stimulation of synovia! fluid lymphocytes with autologous EBV- transformed B-cells and M. tuberculosis purified protein derivative (PPD, Statens Serum Institute; data not shown). Proliferative response assays were performed as above, except that 2 x 10 5 APCs were added per weU and 3 H- thymidine incorporation was determined after three days. Results In order to develop a system to detect antigen presentation by CDl molecules, the abiUty of various recombinant cytokines to induce expression of CDla, CDlb and CDlc on peripheral blood monocytes, which normally do not express significant levels of these molecules, was assessed. Leukocyte -45- Typing TV, Knapp, W., ed., Oxford University Press, Oxford, U.K., pp. 251-269, 1989. High levels of CDla, CDlb and CDlc were consistently observed on monocytes cultured with a combination of granulocyte/monocyte colony stimulating factor (GM-CSF) and interleukin-4 (H_-4) (Fig. la). Alternatively, GM-CSF may be used alone, although the resultant levd of CDl expression is somewhat less than that resulting from. combined GM-CSF and IL-4 treatment. Interleukin-3 (IL-3) may also be used, alone or in combination with other cytokines. Monocytes cultured in the absence of cytokines, or those cultured with interferon-γ, did not express significant levels of ClDa, CDlb, or CDlc (data not shown). Because monocytes are efficient antigen presenting cells (APCs), we reasoned that CDl 4" monocytes might stimulate a CDl restricted T-ceU response to an exogenous antigen. Because most CDl specific T-ceUs identified to date have a double negative (DN; CD4 " 8 " ) phenotype (PorceUi, S., et al., Nature 347:447-450 (1989); Faure, F., et al., Ear. J. Immun. 20:703-706 (1990)), we focused on this subset of cells and generated a T-ceU line by repeated stimulation of peripheral blood of a:β TCR 4" CD4 " 8 " T-cells with a soluble extract of if. tuberculosis and heterologous CDl 4" monocytes (Fig. lb). Functional studies of the resulting T-ceU line (designated DNl) showed that these T-cells gave specific proliferative responses to antigens derived from M. tuberculosis and from closely related M. leprae baciUi, but not to unrelated bacterial antigens such as those from E. coli or tetanus toxoid (Fig. 2a). These responses were dependent on the monocytes being pretreated with GM- CSF and IL-4 (Fig. 2b), and were not restricted by polymorphic MHC determinants (Fig 2c). This lack of MHC restriction was consistent with antigen presentation restriction by non-MHC molecules. In order to determine if CDl molecules are required for M. tuberculosis antigen presentation, the effects of monoclonal antibodies (mAbs) specific for CDl or MHC molecules on the M. tuberculosis induced proliferation of T-ceU Line DNl and a representative subclone, DN1.C7, were determined. Only anti-CDlb mAb showed significant blocking of the M. tuberculosis induced proliferative response, and no consistent effects were observed with anti-CDla or CDlc mAbs or with mAbs against monomoiphic determinants of MHC class I or class II molecules (Fig. 2d). B-ceU transfectants arc effective targets for :β TCR CD4~8~ cytolytic T-cell activity. Using the B lymphoblastoid cell line C1R (Zenmour, J., et al , J. Immun. 748:1941-1948 (1992)). stable transfectants expressing and displaying CDla, CDlb or CDlc at comparable levels were generated and tested for their ability to present M. tuberculosis in a cytolytic assay. Only C IR ceUs transfected with DNA sequences encoding CDlb and incubated with M. tuberculosis prior to the assay were lysed by :β TCR DN T-ceU line DNl and its subclone DN1.C7 (Figs.4a and b). The specificity of this CDlb restricted response was confirmed using two control CD4~8~ ac:β TCR 4" T- cell clones, BK6 and 3C8, which were derived by mitogen stimulation without exposure to M. tuberculosis antigens. Previous studies show that BK6 and 3C8 lyse target-cell lines expressing CDla and CDlc, respectively (data not shown). As for all other CDl reactive T-ceU clones described prior to this disclosure (PorceUi, S., et al.. Nature 347:447-450 (1989); Faure, F., et al., Eur. J. Immun. 20:703-706 (1990); Balk, S.P., etal., Science 253:1411-1415 (1991)), these clones appear to be autoreactive and recognize their nonpolymorphic CDl Ugands in the absence of exogenous antigens. As expected, clones BK6 and 3C8 lysed only C1R transfectants expressing CDla or CDlc respectively, and lysis was not significantly affected by prior incubation of the target-cells with M. tuberculosis (Figs. 4c and d). The lack of MHC restriction demonstrated by the preceding experiments argued that MHC encoded antigen presenting molecules were not involved in the CDlb restricted presentation of if. tuberculosis antigens to line DNl . As a more stringent test of this hypothesis, CDlb transfectants of the T2 ceU line, in which extensive chromosomal deletions in both MHC loci result in a complete lad: of MHC class π molecule expression, were produced. Salter, R.D., et al., Immunogenetics 27:235-246 (1985); ErUch, H., et al. Hum. Immun. 76:205-219 (1986). The MHC linked transporter genes TAP-1 and TAP-2 (reviewed in Pai am, P., Nature 357:193-194 (1992)) are also deleted from T2, resulting in defective expression and function of MHC class I molecules. Hosken, N.A., and Bevan, M., Science 245:367-370 (1990); Wei, M., and CressweU, P.. Nature 356:443-446 (1992). Nevertheless, transfection of CDlb into T2 led to expression of CDlb on the ceU surface at a level simUar to that seen on other transfected B-ceU lines (data not shown) and generated a target-cell that presented M. tuberculosis to Une DNl (Fig. 5a). The presentation of exogenous antigens to T-cells generally requires uptake and processing of complex protein antigen molecules by antigen presenting ceUs, a process which is blocked by aldehyde fixation of the APC surface and by lysosomotropic amines such as chloroquine. Ziegler, H.K., and Unanue, E.R., Proc. Natl Acad. Sci. USA 79:175-179 (1982); Chesnut, R.W., et al., J. Immun. 729:2382-2388 (1982). By these criteria, CDlb restricted presentation of M. tuberculosis also showed a requirement for antigen uptake and processing. MUd fixation of CDlb 4" APCs with glutaraldehyde completely abrogated their abiUty to stimulate line DNl in the presence of if. tuberculosis soluble antigens, although the same APCs pulsed with M. tuberculosis prior to fixation retained their abiUty to stimulate a proUferative response (Fig. 5b). Furthermore, the presentation of M. tuberculosis antigens to line DNl was strongly inhibited by chloroquine with a dose dependence virtually identical to that for the inhibition of MHC class II mediated presentation of mycobacterial antigens (Fig. 5c), indicating that processing of antigens for CDlb and MHC class π restricted responses may involve similar pathways or organeUes, or that the pathways share one or more chloroquine-sensitive ceUular factors. Interestingly, T2 cells have recently been shown to be defective in the processing of antigens presented by MHC class II molecules (Riberdy, J.M., and CressweU, P., J. Immun. 745:2586-2590 (1992)) because T2 cells lack the DMA and DMB genes. Morris, P., et al.. Nature 365:551-554 (1994); Fling, S.P., et al., Nature 368:554-558 (1994). Thus, our finding that CDlb transfected T2 cells can present M. tuberculosis to DNl suggests that the antigen processing requirements for CDlb and MHC class II molecules, although similar with regard to chloroquine sensitivity, are not identical. Several investigators have speculated that T-cells lacking expression of both CD4 and CD8 molecules may recognize antigens presented by cell surface molecules other than those encoded by classical MHC class I and π loci. PorceUi, S., et al., Immun. Rev. 720:137-183 (1991); Janeway, CA. Jr., et al., Immun. Today 6:73-76 (1988); Bluestone, J.A., and Matis, L.A., J. Immun. 742:1785-1788 (1989). The above results show that one member of the CDl family, CDlb, can restrict the specific response of MHC unrestricted CD4~8~ T-cells to an exogenous foreign antigen. Like other CDl proteins, CDlb heavy chains associate noncovalently with /^-microglobulin (Olive, D., et al., Immunogenetics 20:253-264 (1984)) and show limited but significant sequence homology to both MHC class I and class II molecules. Calabi, F., and MUstein, C, Nature 323:540-543 (1986); Balk, S.P., et al., Proc. Natl Acad. Sci. USA 56:252-256 (1989). These structural features of CDlb, together with its critical role in antigen recognition (described above), support the conclusion that CDlb is a nonpolymorphic antigen presenting molecule encoded by a genetic locus unlinked to the MHC. These results indicate a potential role for CDl restricted T-cells in normal host defense against microbial disease. The above results suggest a functional parallel between CDl and MHC class II molecules, since both mediate presentation of exogenous antigens processed through a chloroquine sensitive pathway, and both can also act as ligands for the TCRs of autorcactive T-cells. PorcdU, S., ef al.. Nature 347:447-450 (1989); Glimcher, L.H., and Shevach, E.M., . Exp. Med. 756:640-645 (1982). The limited tissue distribution of CDl molecules in vivo provides a further similarity with the MHC class π family since members of both families are prominently expressed on ceU types involved in antigen presentation to T- cclls, including Langerhans's cells, dendritic cells in lymphoid and many other tissues, 8 cells and possibly cytokine activated monocytes. PorceUi, S., et al., Immun. Rev. 720:137-183 (1991). In contrast, the lack of structural polymorphism of CDl molecules, their unique cytokine regulation on monocytes, and the CD4~8~ phenotype of the CDl restricted T-cells described herein are important differences that distinguish the CDl and MHC antigen presenting systems. These differences point to a distinct role for CDl restricted T-cells in ceU-mediated immunity. Example 2: A Non-Peptide Antigen is Presented by CDlb Methods The CDlb-presented antigen is a nondialyzable macromolecule (data not shown). More antigenic (i.e., T-ceU proUferative) activity could be obtained from soluble aqueous sonicates of if. tb. by adding detergents such as CHAPS or octylglucoside during the sonication (see above). This result suggests that the antigen is hydrophobic. In order to characterize the chemical nature of the antigens presented by CDl, mycobacterial antigens were purified from the nonpathogenic M. tb. strain H37Ra (Difco) and M. fortuitum (a rapidly growing strain that also contains antigenic activity). Bacteria were either commercially available (M. tb. H37Ra, Difco) or grown and harvested (M. fortuitum), sonicated and subjected to sequential fractionation protocols and analyzed for biological activity. AU fractions generated were tested for their abiUty to stimulate the DN T-ceU line DNl in a 5 day proliferation assay using irradiated, GM-CSF- and IL-4-treated monocytes as APCs and measuring 3 H-thymidine incorporation in a 6 hour pulse (PorceUi, S., et al, Nature 360:593-597 (1992)). CeU wall, ceU membrane and cytoplasmic fractions were prepared from either M. tb. or M. fortuitum using a method adapted from published protocols. Hunter, S.W., et al., Journal of Biological Chemistry 265:14065- 14068 (1990). Briefly, ceUs were lyophUized, resuspended in /12190 -.,--.„,- PCT/US95/13274 -50- PBS/octylglucoside, sonicated for 20 minutes and subjected to differential ultracentrifugation to produce cytosolic, membrane, and ceU wall fractions. The ceU wall peUets were further purified by a differential sucrose gradient. Characteristic structural features of the three fractions were confirmed by negative staining with electron microscopy. The majority of the bioactivity for the DNl ceU Une was present within the ceU wall fraction (data not shown). To directly assess whether the CDlb-restricted antigen is a protein, a series of protease digestions of the antigen were performed. Using a variety of endopeptidases with either limited amino acid specificity (chymotrypsin (hydrophobic residues), trypsin (lys, arg), and V-8 (acidic)), or broad amino acid recognition (subtilisin, proteinase K, pronase), sonicates of either M. tb. or M. fortuitum were digested and then assayed for the abitity to induce T-ceU proliferative responses. As a control, a DR7 restricted, CD4 4" T-ceU clone DG.l, derived in this laboratory which recognizes a determinant in mycobacterial PPD (purified protein derivative) was also tested. Analysis by SDS-PAGE and subsequent sUver stain demonstrated that digestion with V8 protease, proteinase K, pronase E or subtilisin degrades the proteins contained in mycobacterial antigen preparations (data not shown). Results The M. tuberculosis antigen recognized by DG.l, a representative CD4+ MHC Class II restricted T-ceU line, is rendered ineffective by treatment with V8 protease, proteinase K, or trypsin (Figure 6). As shown in Figure 6, DG.l cells proliferated strongly in response to the mock digest of the mycobacterial sonicate, but with the exception of chymotrypsin, aU of the other protease treatments completely abrogated the proliferative response. In contrast, the M. tuberculosis and M. fortuitum antigens presented to line DNl by CDlb is unaffected by these broadly reactive proteases (Figures 7 and 8, respectively). The mycobacterial antigen presented by CDlb is fundamentally different than that presented by MHC Class I and II antigen presenting molecules. It is well established that MHC molecules bind and present peptide antigens of about 8-9 amino adds for class I and 13-25 amino acids for class π. Because this CDlb-presenled antigen is a macromolecule which is protease resistant, it is unlikdy to be a peptide. Thus, the CDl system is the first known antigen presentation system which present foreign substances other than peptides to a:β TCR 4" T-ceUs. Example 3: Purification of a CDlb-Presented Antigen from M. tuberculosis Methods M. fortuitum bacteria were grown in liquid culture to stationary phase and collected by centrifugation, sterilized by stream autoclaving (250°C, 18 p.s.i.) and lyophUized. Desiccated M. tb. (strain H37Ra, Difco) or M. fortuitum bacteria were suspended in phosphate buffered saline (200 mg bacteria per 5 ml PBS), and the bacterial suspension was sonicated with a probe sonicator to disrupt the cells. The resulting sonicate was extracted with organic solvents using a Folch based 2 phase extraction system (chloroform/methanol/water) which quantitatively extracts mycobacterial Upids into an organic phase. Goren, M.B., and Brennan, P.J., Mycobacterial Lipids: Chemistry and Biologic Activities in Tuberculosis, 1979. The sonicate was combined with three volumes of a chloroform:methanol (2: 1 v/v) solution in a glass container, and the mixture was vigorously shaken at room temperature for 24 hours. The phases of the, mixture were separated by centrifugation at 800 g, and the organic phase was coUected and transferred into a glass boiling flask. Each fraction was then dried by rotary evaporation (organic phase) or lyophUized (aqueous phase and interface). After evaporation, the organic phase left a thin film of waxy material on the surface of the flask. In order to prepare material to be tested in T-ceU proliferation assays, aliquots of fractions were reconsti ted as liposomes by the addition of water (20 ml per 200 mg of bacteria in original sonicate) foUowed by sonication in a water bath sonicator. The resulting crude suspension was then forced repeatedly through a 0.1 nm filter membrane in order to create a liposome suspension of uniform size. Alternatively, T-ceU media with 10% fetal calf serum was added to the dried fraction and sonicated without additional preparation. For further purification, the material extracted from M. tuberculosis as described above was dissolved in hexane and appUed to a column of Silicic Acid. Eluting with organic solvents of increasing polarity over s ' ύica columns achieves separation of lipids based on their polarity. The most polar Upids such as phosphoUpids bind the strongest to the silica column and elute last, while glycolipids generally bind less tightly and elute earlier. Neutral lipids such as triglycerides or sterols bind the weakest and therefore elute first. Small open soUd phase extraction (SPE) columns (BakerBond, JT Baker) were preferred because of the abUity to process many samples simultaneously. A siUca based "bonded" column (covalently linked) with cyano (CN) functional groups was used to fractionate the organic extracts of M. tb. The organic phase of the choloroform methanol extract of bacteria was dried and resuspended in hexane. The equivalent of 5.3 mg of desiccated bacteria in 200 μl hexane was loaded onto a 0.5 gram CN SPE column. The column was washed with hexane and then with 25% (v/v) chloroform in hexane. Next, the bioactive fraction was eluted with 85% (v/v) chloroform in hexane with over 100% recovery of bioactivity. Analyzing the active fraction on silica based TLC plates, according to the method of Kupke and Zeugner (Christie, W.W., Lipid Analysis, p. 117, Pergamon Press, Oxford, U.K., 1982)), only two major species of Upid were visualized with cupric acetate, corresponding to free fatty acids and mycolic acids (data not shown). This result reflects a marked purification from the starting organic material. Proliferation assays were harvested on day 2 (DG.SF68), day 3 (DG.1) or day 5 (DNl). DG.SF68 is a Vγ2Vδ2 T-cell clone derived in this lab (PNAS in press, CM). APCs were GM-CSF- and IL-4-treated monocytes (DNl) or PBMC (DR7 + ) (DG.l), or untreated PBMC (DG.SF68). Cytolytic assays are displayed as % specific lysis and were performed as described. PorceUi, S„ et al., Nature 347:447-450 (1989). Data shown (Figure 9) are with an effector to target ratio of 50:1 and with M. tuberculosis antigen at a dUution of 1:20. Results The relevant antigen of if. tuberculosis is isolated from a commercial preparation of strain H37Ra (Difco) by extraction into a mixture of chloroform and methanol as described above. Although the interface contains greater than 95% of the proteins, 100% of the CDlb-restricted antigenic activity (i.e., abiUty to induce an cc:β TCR DN T-ceU proUferative response) of the mycobacterium extracts into the organic phase (Figure 9a). This strongly supports the original conclusion of the nonpeptide nature of the relevant bacterial antigen. In contrast, a conventional MHC class π restricted antigen recognized by DN y:δ TCR 4* T-cells was located in the phase interface between the aqueous and organic phases (Figure 9b). In contrast, in four independent antigen preparations, the CDlb-restricted antigen quantitatively partitioned into the organic phase. Results of transfectant cytolytic assays of the phases confirmed that the CDlb-presented antigen is present in the organic phase (Figure 10). Under these conditions, 100% of the mycobacterial CDl-presented antigenic activity was quantitatively recovered after CN SPE chromatography. In addition, the organic phase extraction served as an exceUent purification step and the organic phase was used as a starting material for subsequent chromatography. An alternative and somewhat more general procedure to purify the antigen for subsequent chromatography is to saponify whole or sonicated bacteria and extract with an acidified solution of hexanes. Further purification of the antigen is oblained using Silicic Acid chromatography as described above. Example 4: MycoUc Acid ft a Mycobacterial CDlb-Presented Antigen - Given _e a-ove res__. _- oth_ ,>r--__^ T^eU stimulatory activity co«hιo__-grapbe- on CN modify silica HP IT coiomns with preparations of free fatty acid acyl chains <da_ not shown), i t seemed plausible that the CD lb-presented antigen is a unique mycobact-nal lipid, possibly a mycolic acid. 0 M ycobac_r_co_-in_ 1 _-_ordin_, propor_ nofUp-s, -no___g to 40% of the dry weigh, of bacillus and 60% of the cell wall; the mycolic acids are perhaps the most numerous __ diverse members of mycobacterial Hpids. loren. M.B.. -- Bre___, PJ.. My«--_«r_J _*__.- O-m-rry and Biologic AcivitUs in Tuberculosis, 1979. Mycolic acids are α -branched. IS β-hydroxy fatty acids forming a unique set of sttuctnrcs that are found i n mycobacteria and related bacterial species. Wolinsky, E.. -Mycobacteria.- 3rd Ed.. Davis. B.H., ed.. Harper & Row. -___elp-_. 1980. MycoUc acids are principally found in the ceU wall, esterified to ,0 arabinogalactan polymers linked to the core peptidoglycan (McNeil, M.R.. and Bre___, PJ.. -*- *>»•«■ 2*Sl-∞ (1991); Besra, OS.. Bioch-misuy JfcTTO-7777 (1991); McN-1. M., _ al. Journal of Biological Chemistry __5:13217-132_3 (1991)) and can be released by either alkaline or acid hydrolysis (sapo_-_--m). Min___. D.E.. 'Mycolic a ds' in CRC 25 Handbook of Chrowmgra≠s: Amt≠s tfUptds, Murhetgee. .D... and Weber. N., eds.. CRC Press, 1993. Mycolic acids are the major component of the' lipid coat surrounding the organism, giving the organism its hydrophobic surface _ri cb_ac_r_t„ »^ ^ Goren, M.B... and Brennan, P.J., Mycobacterial Lipids: Chemistry and Biologic Activities in Tuberculosis, 1979. Unlike eukaryotic and bacterial fatty acids, which range in size from c 12" c 24- mycolic acids of Mycobacteria range in size from C50-C90. Minnikin, D.E. , "Lipids: Complex Lipids, their Chemistry. Biosynthesis and Roles" in The Biology of Mycobacteria, VoL 1, Ralledge, C, and Sanford, J., eds.. Academic Press, London, 1982. MycoUc adds, in contrast to the straight chain fatty acids, have a branched alkyl group at the a carbon and a hydroxyl group at the β carbon. Gorcn, M.B.., and Brennan, P.J., Mycobacterial Lipids: Chemistry and Biologic Activities in Tuberculosis, 1979; Minnikin, D.E., "Lipids: Complex Lipids, their Chemistry, Biosynthesis and Roles" in 77i£* Biology of My∞bacteria, Vol. 1, Ratledge, C, and Sanford, J. f eds., Academic Press, London, 1982; Takayama, K., and Qureshi, N., "Structure and Synthesis of Lipids" in The Mycobacteria: A Sourcebook, Part A, Kubica, G.P., and Wayne, L.G., eds., Marcel Dekker, New York & Basel, 1984. The main long alkyl chain of the mycolic acid (the so-called mero group) is heterogenσus both in length and in attached functional groups. In addition to alkene groups (double bonds), the functional groups of mycoUc acids include methoxyl, keto, lone methyl balances, ethylenic and cyclopropanoid groups. Minnikin, D.E., "lipids: Complex Lipids, their Chemistry, Biosynthesis and Roles" in The Biology of Mycobacteria, Vol. 1, Ratledge, C, and Sanford, J., eds., Academic Press, London, 1982. The large array of functional groups avaUable to mycoUc acids, their variable chain length, and their heterogeneity among strains, aUow mycoUc acids to achieve a potentiaUy large degree of antigenic variation similar to that provided by peptides with heterogeneity among amino acid side chains. Thus, these Upid molecules may have an immunological relevance not previously appreciated. For each mycobacterial species a distinguishable fingerprint exists based on the patterns of mycoUc acid molecules present. Such patterns have been determined for individual species by thin layer chromatography (TLC). Minnikin, D.E., "Lipids: Complex Lipids, their Chemistry, Biosynthesis and Roles" in The Biology of Mycobacteria, Vol. 1, Ratledge, C, and Sanford, J., eds., Academic Press, London, 1982; Dobson, G., et al.. Chemical Methods in Bacterial Systematics, Academic Press, 1985; Valero-GuUlen, P.L., et al.. Journal of Applied Bacteriology 59:113-126 (1985)), gas chromatography (G (Valero-GuiUen, P.L., et al.. Journal of Applied Baaeriology 59:113-126 (1985); Athalye, M., et aL, Journal of Applied Baaeriology 58:501-512 (1985); Luquin, M., et aL, Journal of Clinical Microbiology 29:120-130 (1991)) and by high pressure Uquid chromatography (HPLC). Qureshi, N., et al.. Journal of Biological Chemistry 253:5411-5417 (1978); Qureshi, N., et al , Journal of Biological Chemistry 255:182-189 (1980); Butler, W.R., et al.. Journal of Clinical Microbiology 29:2468-2472 (1991); Butler, W.R., and KUburn, J.O., Journal of Clinical Microbiology 28:2094-2098 (1990). Methods In order to determine if the CDl-presented antigen described above is a mycoUc acid, an HPLC method that separates mycoUc acids on C18 reverse phase column chromatography was used to prepare mycoUc acids. Butler, W.R., et al.. Journal of Clinical Microbiology 23:182-185 (1986); Butler, W.R., et al.. Journal of Clinical Microbiology 26:50-53 (1988); Floyd, M.M., et al. Journal of Clinical Microbiology 30:1327-1330 (1992). Reversed phase chromatography separates acyl chains primarily on the basis of the length of the acyl chain or "carbon number," thus it is relatively easy to achieve good separation between free fatty acids and mycoUc acids which are much larger. This HPLC method requires an initial saponification of the sample, foUowed by derivitization of the fatty acids or mycolic acids with the ultraviolet (OD254) absorbing compound p-bromophenacylbromide, which attaches to the carboxyl terminus of an acyl chain. In preliminary experiments, we determined that the process of derivatizing the bacterial fraction with p-phenacylbromide destroyed bioactivity. However, the CDlb- restricted antigenic activity could then be recovered by saponifϊcation with methanoUc KOH, a process which frees the carboxyl end of the acyl chain by cleaving off the phenacylbromide groiφ (as assayed by OD254 on HPLC). This result indicates that the acyl chain must be deaved in order to achieve a form which is presentable by CDl positive APCs and/or that a free carboxyl group is critical for presentation of the CDlb-restricted antigen. This is additional evidence that the antigen comprises an acyl chain. The SPE CN column purified preparation (Example 3) was used as a starting material for the C18 chromatography. Samples were saponified with methanolic KOH and derivatized with the UV absorbing group bromophenacyl bromide. The active fraction was run on a C18 column (AUtech NucleosU C18 5 μm, 25 cm x 4.6 mm) using a linear gradient of 30 to 90% methylene chloride in methanol over 50 minutes at 1 ml min. Using as a reference a C 0 internal standard (Ribi), tiie resulting chromatogiam (Figure 12, panel a, upper portion) has a pattern comparable to published results. Floyd, M.M., et al. , Journal of Clinical Microbiology 30: 1327-1330 (1992). Fractions were resuspended in complete media with 10% FCS and tested at a 1:17 dilution relative to the original sonicate volume. Results Bioactivity, assayed by the T-ceU proliferative response assay, was found to comigrate with early peaks in the region of the mycoUc acids (Fig. 12a). To confirm that mycoUc acid is presented by CDlb, an alternative source of mycolic acids, purified cord factor (trehalose dimycolate; Fig. 11) was tested. Upon saponification, purified trehalose dimycolate from either M. tb. (from Sigma) or M. kansasii (gift of Patrick Brennan) stimulated the proliferation of the T-ceU line DNl (Fig. 12b). However, no stimulation was achieved by material prepared from saponified trehalose dibehanate, a synthetic derivative of cord factor which contains two Gg fatty acid chains, rather than mycolic acids, that are liberated by saponif i cation. This strongly argues that mycolic acid, not trehalose (which is present in each of the samples) nor fatty acids, is the antigen presented by CDlb to the double negative c t :β TCR T-ceU line DNl . A HPLC analysis of the saponified Sigma cord factor was then performed, and again the bioactivity was located in fractions corresponding to the early mycoUc acid peaks (Fig. 12c). Together, the above data demonstrate that the CDlb restricted mycobacterial antigen recognized by the T-ceU line DNl is a species of mycoUc acid. Mycobacteria are known to be highly effective adjuvants. Aldovini, A., and Young, R.A., Nature 357:479-482 (1991). One source of the CDlb- presented antigen, mycolic acid, used herein is trehalose dimycolate (i.e., Mycobacterial cord factor), which has been shown to enhance , antibody formation (Bekierkunst, A., et al., J. Bacteriol. 700:95-102 (1969); Bekierkunst, A., et al, Infeaion and Irnrmmuy 4:245-255 (1971); Bekierkunst, A., et al. Infection and Immunity 4:256-263 (1971)) and to stimulate nonspecific immunity to bacterial infections (Parant, M., et al., Infect. Immun. 20:12-19 (1978)) and tumors (Bekierkunst, A., etal., Infeaion and Immunity 70:1044-1050 (1974). In order to ensure that the purified antigenic activity contains a bona fide antigen and not a nonspecific mitogen, we looked at the specificity of the T-ceU proliferative response to crude M. tb. preparations and HPLC-purified mycoUc acid from if. tb. and saponified cord factor. Total sonicates of if. tb. (Fig. 14, upper panel) contain antigen recognized by the MHC class II restricted CD4 4 " a:β TCR 4" T-ceU line DG.l, as weU as an antigen recognized by the CDlb-restricted T-ceU line DNl and the CDlc-restricted T-ceU line DN6 (see Example 5, below). However, HPLC-purified mycoUc acid from either M. tb. (Fig. 14, middle panel) or from saponified cord factor (Fig. 14, lower panel) contains antigens recognized only by CDlb-restricted DNl T-ceUs. This specificity is also demonstrated in the transfectant cytolytic assay (Fig. 13). The CDlb-restricted response of DNl was blocked by anti- CDlb antibodies, but was not affected by antibodies to MHC class I or II (Figure 15, upper panel). Example 5: Antigen Presentation by CDlc In addition to the presentation of antigens by CDlb disclosed in Example 1, CDlc molecules also present antigens. A separate CD4~8 " cr.β TCR 4 " T-ceU line, derived by repeated stimulation with monocytes treated with GM-CSF and IL-4 (to induce CDl expression) and M. tuberculosis antigens was isolated and named DN2 (also referred to as 8.23.DN1). Proliferation of DN2 is completely inhibited by the addition of mAbs to CDlc, but is not affected by mAbs to CDlb (Figure 15, lower panel). A cytolytic assay corrfirms this result: C1R cells transfected with vector only or with vector encoding CDla, CDlb or CDlc were preincubated with or without M. tuberculosis sonicate and used as targets in a cytolytic assay. Only CDlc 4" C1R cells are recognized (Fig. 16); recognition is enhanced by preincubation with the sonicate. Therefore, CDlc molecules present M. tuberculosis antigens to DN2 T-cells. A second CDlc-restricted CD4~8 " c :β TCR + T-ceU line, derived by repeated stimulation with monocytes treated with GM-CSF and IL-4 (to induce CDl expression) and M. tuberculosis antigens was isolated and named DN6. Cytolytic assays (Fig. 17) indicate that DN6 lyses CDlc 4* cells in the presence of if. tb. antigen. Example 6: Characterization of a CDlc-.Presented Antigen from M. tuberculosis The antigen presented to DN6 T-cells by CDlc is not mycolic acid (Fig. 14, middle panel). However, chemical characterization of the antigen recognized by DN6 indicates that the antigen is a complex lipid. When M. tb. sonicates are extracted with chloroform:methanol (as described in Example 3), the antigenic activity is found substantially in both the phase interface and the organic phase (Fig. 18). Antigen recovered from the organic phase can be bound to CN SPE columns and eluted (as described in Example 3). These studies demonstrate that the antigen is hydrophobic and has tiie chromatographic properties of a lipid. However, unlike the CDlb-restricted πtycobacterial antigen, results of additional experiments indicate that the DN6-recognized CDlc-presented antigen is a complex lipid and not a free acyl chain. Saponification of if. tb. sonicates eliminates the proliferative response of DN6 (Figure 20). Because saponification breaks ester linkages that connect acyl chains to carbohydrate backbones, this result suggests that the antigen recognized by DN6 T-cells is a, or comprises an additional, moiety other than a free acyl chain. Saponification presumably destroys or removes the additional moiety which may be, e.g., a polysaccharide backbone or branch point. Thus, in contrast to the recognition of free mycoUc acid by the DNl T-ceU line, the DN6 T-cell line recognizes a more complex Upid structure. It is noteworthy that the CDl-presented antigens recognized by T-ceU lines DNl and DN6 are not unique to M. tuberculosis. Rather, the DNl- and DN6-recognized CDl-presented antigens are cross-reactive to antigens found in many Mycobacterial species tested to date (M. fortuitum, M. avium, M. bovis (BCG) and M. leprae). In the case of CDlc-restricted recognition by DN6 T-ceUs, an antigen is recognized in Corynebacteria (data not shown), a separate but related genera of bacteria which produce mycoUc acids. Takayama, K., and Qureshi, N., "Structure and Synthesis of Lipids" in The Mycobacteria: A Sourcebook, Part A, Kubica, G.P., and Wayne, L.G. , eds. , Marcel Dekker, New York & Basel, 1984. Thus, CDl-presented. antigens include at least several bacterial Upid antigens; in the case of autoimmύnity, CDl-presented antigens include endogenous Upid antigens. Example 7: CDl-Preseήted Antigens from M. leprae In order to derive DN ct:β TCR 4" T-cell lines from leprous lesions, T- ceUs from such lesions or PBMC were stimulated by culture with CDl 4" APCs and M. leprae. Immunomagnetic depletion removed CD4 + , CD8 + and <y:_-TCR + T-cells. The abUity of remaining CD4~8 " cr.β TCR 4" T-cells to respond to M. leprae antigens was assessed by 3 H-thymidine incorporation using aUogenic CD1+ monocytes as APCs. Four of six DN :β TCR 4" T-ceU lines isolated in the above manner proliferated strongly in the presence of M. leprae and aUogenic CDl + APCs, whereas little or no stimulation of growth was detected in the presence of the aUogenic CDl + APCs alone, and no proliferation in reponse to M. leprae was detected in the presence of APCs not expressing CDl proteins. Thus, the four DN :β TCR 4" T-ceU lines respond to, and proliferate in the presence of, CDl-presented antigen from M. leprae. Two DN :β TCR 4* T-cell lines, isolated from leprous lesions and designated LDN1 and LDN4, were subjected to further analyses. To determine which CDl molecules (i.e., CDla, CDlb, Cdlc, etc.) were specificaUy responsible for M. leprae antigen presentation, two sets of experiments were performed. First, proliferation studies were performed in which CDl + APCs were incubated with antibodies to CDla, CDlb or CDlc. Second, CIR ceUs were transformed with genes encoding different CDl molecules and used as target cells in cytolytic assays. M. leprae- dn ed proliferation of the LDN1 T-ceU line was inhibited by greater than 63% by anti-CDlc, but anti-CD la, anti-CDlb and an isotype- matched non-CDl-reactive antibody had no effect on the proliferative response to M. leprae (Figure 20, upper panel). Similarly, LND1 cells lysed CDlc- transformed CIR cells in an if. leprae antigen specific manner, but did not lyse cells transfected with Cpia or CDlb or mock transfected CIR ceUs. A second M. leprae antigen reactive DN or:/- TCR + T-ceU line derived from a leprous lesion, LND4, was found to be Cdlb restricted. The ability of this T-cell line to proliferate in the presence of M. leprae was completely inhibited by the addition of anti-CDlb monoclonal antibodies (MAbs) (Figure 20, lower panel). SimUarly, LND4 lysed CDlb-transfected CIR cells in an antigen specific manner, but did not lyse CDla or CDlc transfectants. Furthermore, the abiUty of LND4 to lyse antigen-pulsed CDlb targets was blocked by anti-CDlb MAbs. In all DN a:β TCR + T-ceU Unes tested, antibodies to MHC class I and class II molecules had no effect on proliferation in response to M. leprae. The presence of CDl-bearing cells in leprous lesions was examined by immunohistological examination of tissue sections using MAbs to CDl (data not shown). These analyses reveal that CDla+, CDlb+ and CDlc+ cells occur in in tuberculoid granulomas to a greater extent than in lepromatous granulomas. Although CDla was expressed in the epidermis as weU as the dermal granulomas of tuberculoid leprous lesions, CDlb and CDlc were only expressed in dermal granulomas. Furthermore, U-10, which is strongly expressed in lepromatous lesions (Yamamura, M., etal.. Science 254:277-279 (1991)) could inhibit the expression of CDl on monocytes (data not shown). The correlation of CDl expression with resistance in leprosy suggests a role for CDl-mediated restriction in the generation of ceU-mediated immunity. The functional role of DN a:β TCR 4" T-cells was examined by studying their cytokine secretion patterns. Anύ-CD3 stimulation of DN cr.β TCR 4" T-cells resulted in the release of interferon-γ (IFN-γ) (median = 647 pg/ml) in four of the five DN a:β TCR + T-ceU lines, but produced little or no IL-4 (median < 20 pg/ml), although one T-ceU line produced E -4 (99 pg/ml) but no detectable IFN-γ ( <20 pg ml). IL-5, IL-6 and IL-10 were not detected in the superantants of anti-CD3-stimulated DN T-cells. These data suggest that the majority of if. Z-prαβ-reactive DN a:β TCR 4" T-cells secrete the type 1 cytokine pattern. Example 8: LAM is a CDlb-Presented Antigen from M. leprae In order to elucidate the biochemical nature of the antigens recognized by CDl-restricted T-ceUs, purified ceU wall constitoents of M. leprae were prepared and assayed for biological activity. LDN4, in the presence of CDl expressing antigen presenting cells, proliferated in response to lipid-containing fractions derived from the cell waU (SolPCW), but not to protein-enriched fractions from the membrane and cytosol that have been depleted of Upids (SP-) (Figure 21). No response was observed to insoluble fractions of the ceU wall (CWC) or to mycolic acid-arabinogalactan-peptidoglycan (mAGP). These data indicate that DN ctβ T-cells recognize non-peptide antigens of if. leprae in a CDl-restricted manner. The reactivities of LDN4 correlated with the presence of lipoarabinomannan (LAM; Figure 22), and we subsequently found that this line proliferated to purified LAM. The ability of LDN4 to respond to LAM was blocked by anti-CDlb antibody (Figure 23). BDN2, an :β double negative T-ceU line which responds to M. leprae in a CDlc restricted manner, also responded to LAM. The abiUty of BDN2 to respond to LAM was blocked by anti-CDlc antibody (data not shown). Example 9: Derivatives and Analogs of LAM, and CD1- Dependent Uses Thereof LAM is a nonprotein molecule, one of a class known as "amphiphUes, " possessing both hydrophobic and hydrophiUc components (Figure 22). Hunter, S.W., etal., J. Biol. Chem. 267:12345-12531 (1986); Hunter, S.W., et al., J. Biol. Chem. 265:9212-9219 (1990). The hydrophobic domain is a phosphatidyl inositol linked to a hydrophUic heteropolysaccharide composed of a niam-ian core and branched arabinan side chains with short mannose oligosaccharide "caps." Chatterjee, D., etal., J. Biol. Chem. 267:6228-6233 (1992); Chatterjee, D., et al. J. Biol Chem. 267:6234-6239 (1992). Protocols for the purification of LAM have been described. Hunter, S.W., et al., J. Biol Chem. 267:12345-12531 (1986). Fast Atom Bombardment- Mass Spectrometry analysis indicates the virtually complete purity of the M. leprae LAM (>99.9%). Previously, M. leprae and M. tuberculosis LAM have been shown to have distinct structures which result in different B-ceU epitopes. Prinz-S, S., etal.. J. Gen. Microbiol. 739:2649-2658 (1993). Therefore, it is conceivable that LAM from different mycobacterial species may possess distinct T-ceU epitopes. It is also noteworthy that gram positive bacteria contain stiuctuaUy related glycoUpids such as Upoteichoic acids, so that recognition of these molecules by T-cells may be a part of the immune response directed generally to bacterial pathogens. To determine the domain(s) of LAM responsible for stimulating DN a:β T-cells, chemical derivatives of LAM were tested for their abUity to stimulate DN a:β T-cells. Mild alkaline hydrolysis releases the fatty acid moieties of LAM, while leaving the carbohydrate intact. This deacylated LAM (dLAM) loses the abiUty to stimulate LDN4 at concentrations where the native LAM caused striking T-ceU proliferation (Figure 24). In contrast to deacylated LAM, phosphatidylinositol tαannoside (PIM) stimulated LDN4 ten¬ fold more than media alone (Figure 24). These data suggest that the lipid domain of LAM is required for T-ceU stimulation, but that the repeating mannan-arabinan backbone of LAM may not be required. Finally, the cross-recognition of LAMs from other mycobacteria was investigated with regard to two D α:|8T-ceU lines (Figure 25). The leprosy- derived T-cell line LDN4 was stimulated by M. leprae LAM (Lep LAM), but not by LAM from a clinical isolate of if. tuberculosis (TBE-LAM) or LAM from a virulent laboratory strain of if. tuberculosis (Rv LAM). These results demonstrate a species specificity of LDN4 for M. leprae LAM. In contrast, T-cell line BDN2 responded to M. tuberculosis LAM (TBE LAM and Rv LAM) as weU as to M. leprae LAM (Lep LAM). Taken together, these results demonstrate that both species-specific and cross-reactive determinants of LAM are recognized by DN cr.β T-cells. Example 10: Vaccines Comprising CDl-Presented Antigens Prior to the present disclosure, Upids or glycoUpids were not known to possess potentiaUy potent specific T-ceU-mediated immunogenidty. The CDl-presented Upid and glycoUpid antigens or their functional equivalents described herein can be used as essential components of compositions designed to function as vaccines to bacterial, fungal or protozoan pathogens. Vaccines comprising CDl-presented antigens can be administered directly by parenteral, mucosal or topical means. For example, due to the presence of CDl on ceUs found in the gastrointestinal epithelium (Bleicher, P. A., et al.. Science 250:679-682 (1990)), oral administration of vaccines comprising CDl-presented antigens can introduce such vaccines into an anim l in need of a vaccine comprising a CDl-presented antigen. CDl-presented antigens can be combined with other antigens, either another CDl-presented antigen or an MHC Class I or MHC Class π-presented antigen, to produce a more effective prophylactic or therapeutic vaccine. Vaccines comprising the CDl-presented antigens of the present invention are formulated according to known methods. Remington Pharmaceutical Sciences, 18th Ed., Gennaro, A.R., ed., Mack, Easton, 1990; The Pharmacologist Basis of Therapeutics, 7th Ed., Gilman, A.G., et al., eds., MacMUUian, New York, 1985. PharmaceuticaUy acceptable Upid-stabilizing and -solubilizing agents known to those of skiU in the art can be added to vaccines comprising CDl-presented antigens to enhance their effectiveness. Teng, N., et al, PCT published patent application WO 91/01750 (February 21, 1991); Nunberg, J.H., U.S. Patent 4,789,702 (December 6, 1988). Example 11: Means and Methods for Inhibiting CDl- Restricted Antigen Presentation The disclosure of CDl antigen presentation system aUows for various means and methods of inhibiting CDl-restricted antigen presentation. Any composition which inhibits the processing of CDl-presented antigens, which interferes with the binding of antigen to a CDl molecule, or which interferes with the binding of the CDl:antigen complex to a TCR molecule, wiU inhibit CDl-restricted presentation of antigen. Such compositions, called CDl blocking agents, are useful for controUing undesired T-ceU-mediated immunity which occurs, e.g., in autoimmune diseases. Oksenberg, J.R., et al., J. Neurol. Sci. 115 (Suppl ):S29-S37 (1993). CDl blocking agents include, but are not limited to, (1) a purif i ed CDl molecule, or a synthetic derivative thereof, capable of binding a CDl- presented antigen and preventing the antigen's interaction with CDl displayed on APCs; (2) a purified TCR polypeptide, or a synthetic derivative thereof, capable of binding to a CDl-antigen complex on a CDl 4" APC and preventing the complex's interaction with T-ceU receptors; (3) an antigen antagonist comprising a chemically-modified CDl-presented antigen, or a synthetic derivative of a CDl-presented antigen (4) a purified CDl-antigen complex, or a synthetic derivative thereof, capable of binding to a T-ceU receptor that recognizes a CDl-antigen complex on a CDl 4" APC and preventing the T-ceU receptor's interaction with CDl-antigen complexes; (5) an antibody which binds a CDl molecule and thus prevents the interaction of the CDl molecule and a CDl-presented antigen; (6) a polyclonal or monoclonal antibody which binds a CDl:antigen complex and thus prevents the interaction of the CDl ' .antigen complex and its cognate TCR; (7) a polyclonal or monoclonal antibody which binds a TCR that recognizes a CDl-presented antigen and thus prevents the interaction of the TCR with its cognate CDl:antigen complex; and (8) a composition which blocks an essential step in the pathway by which CDl-presented antigens are processed prior to being displayed. The preceding Examples contain exemplars of CDl blocking agents as follows. CDl blocking agents of type (5) are represented by monoclonal antibody WM25 to CDlb, which specificaUy inhibits CDlb-restricted antigen presentation (Fig. 15, upper panel) and monodonal antibody 10C3 to CDlc, which specificaUy inhibits CDlc-restricted antigen presentation (Fig. 15, lower panel). A skiUed artisan can used the methods described herein to isolate antibodies which act as CDl blocking agents of type (6) or (7), and those of skiU in the art know how to formulate antibodies for therapeutic purposes. A Critical Analysis of Antibody Therapy in Transplantation, Burlington, W.J., ed., CRC Press, Boca Raton, 1992. CDl blocking agents of type (8) are represented by chloroquine (Fig. 5c), which inhibits a step in the processing of CDlb-restricted antigens. Methods of formulating and administering chloroquine are known to those of skiU in the art. Webster, L.T., "Drugs Used in the Chemotherapy of Protozoa! Infections," Chapters 41 and 42 in Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th Ed., Gilman, A.G., et al., eds., Pergamon Press, New York, 1990. Although cWoroquine also inhibits MHC- restricted antigen presentation, those skiUed in the art can, using the methods disclosed herein, identify and/or isolate compositions which specificaUy inhibit processing of CDl-restricted antigens. Blocking agents of type (3), i.e., antigen antagonists, may be derived from CDl-restricted antigens isolated by the methods of the invention. Variants of MHC-restricted peptide antigens, binding with weaker affinities than the original peptide antigen, act as antagonists for mature T-cells in MHC-restricted antigen presentation. Wraith, D.C., et al., Cell 59:247-255 (1989); SmUek, D.E., et al.. Proc. Natl Acad. Sci. (USA) 88:9633-9637 (1991). In like fashion, CDl-presented antigens are isolated by the methods of the invention and are chemicaUy modified, according to standard techniques, in order to generate non-antigenic or weakly antigenic CDl- presented antigen derivatives. For example, mycoUc acid derivatized with p- bromophenacylbromide is non-antigenic (Example 4). Antigen antagonists are identified as CDl-presented antigen derivatives which inhibit or prevent the T-cell proliferative or CDl transfectant cytolytic responses which occur when only the original, unmodified CDl-presented antigen is present (Example 1). Blocking agents of type (2), i.e., TCR derivatives which block the interaction of the antige CDl complex with the TCR molecules on T-cells, may be prepared from the disclosure by those skiUed in the art. DNA molecules encoding TCR polypeptides displayed by a T-ceU Une that recognizes a CDl-presented antigen of the invention are isolated according to methods known in the art. Oskenberg, J.R., et al, Proc. Natl Acad. Sci. (USA) 86:988-992 (1989); Oksenberg, J.R., etal, Nature 345:344-346 (1990) . and erratum, Nature 353:94 (1991); Uematsu, Y., et al, Proc. Natl. Acad. Sci. (USA) 88:534-538 (1991); Panzara, M.A., et al, Biotechniques 72:728- 735 (1992); Uematsu, Y., Immunogenet. 34:174-178 (1991). The DNA sequence is converted into a polypeptide sequence, and the portion of the polypeptide sequence that corresponds to the antigen-binding variable region of a TCR polypeptide is used to design synthetic oUgopeptides that bind CDl:antigen complexes on APCs, thereby inhibiting antigen presentation. OUgopeptides are chemically synthesized according to standard methods (Stewart and Young, Solid Phase Peptide Synthesis, Pierce Chemical Co., Rockland, IUinois, 1985) and purified from reaction mixtures by reversed phase high pressure liquid chromatography (HPLQ- Pilot trials of treatment of humans suffering from an autoimmune disease with peptides derived from MHC-restricted a:β TCR molecules is currently underway. Oksenberg, J.R. , et al., J. Neurol. Sci. 115 (Suppl) :S29SZ1 (1993). TCR-derived peptides which function as CDl blocking agents are identified as TCR-derived peptides which inhibit or prevent the T-cell proliferative or CDl transfectant cytolytic responses which occur in the presence of CDl-presented antigen (Example 1). The assays for CDl-presented antigens described herein may be used to screen molecular libraries for CDl blocking agents. Libraries of molecularly diverse compositions are prepared by chemical, biochemical and/or biotechnological means. Such libraries include combinatorial tibraries of synthetic peptides (Houghten, R.A., et al, BioTechniques 73:412-421 (1992)) and fusion protein libraries prepared by recombinant DNA technology, e.g., phage display libraries. Koivunen, E., etal., J. Biol Chem. 268:20205- 20210 (1993). The Ubraries are screened for the presence of members which inhibit or prevent the DN T-ceU proUferative and or CDl cytolytic responses described herein. CDl blocking members are isolated from the library according to techniques known in the art and appropriate for the type of tibrary employed. Lowman, H.B., et al.. Biochemistry 30:10832-10838 (1991); Felicia, F. , et al., J. Mol. Biol 22:301-310 (1991); Dandekar, T. , et al., Neurochem. Int. 7:247-253 (1985); Owens, R.A., et al, Biophys. Res. Commun. 787:402-408 (1991). In order to detect a CDl blocking agent in a sample, assays for CDl- presented antigen are performed in duplicate. The first (control) assay is a T- cell proliferative or cytolytic assay performed essentiaUy as described in Example 1. The second assay is substantially the same as the first assay except that the second assay additionally contains a sample suspected of containing a CDl blocking agent. The presence of CDl blocking agents in the sample correlates with a T-ceU proliferative or cytolytic response in the second assay that is significantly less than that measured in the first assay. Example 12: T-Cell Reactivity to CDl-Presented Antigens As described in Example 1, T-cell reactivity to CDl-restricted antigens was initially found among a subset of T-cells, i.e., CD4U' TCR aβ* T-cells. However, additional examples of CDl-restricted foreign antigen recognition of microbial antigens is also found in CD8* TCR aβ* T-cells, as weU as among TCR yδ + T-cells. CD1 Restricts the Response of TCR yδ* T-cells to an Antigen Human peripheral mononudear cells were obtained from a leukopak. After depletion of the monocyte population by plastic adherence, TCR *γδ + T- ceUs were isolated using magnetic ceU sorting (MACS) as previously described (Schittek, B. and Rajewsky, K., Nature 346:749-751 (1990)). Briefly, PBMC were labeUed with biotinylated anti--γδ TCR monoclonal antibody (TCRδl), followed by staining with FITC-Avidin (CALTAG) and biotinylated beads (MUtenyi Biotec, Sunnyvale, CA). Cells were then positively selected in a strong magnetic field through a high capacity (3xl0 7 ceUs) column (MUtenyi Biotec, Sunnyvale, CA). The purity of the cells was assessed by FACS immediately after purification. Starting from 2x10' PBMC, this procedure typically allows one to obtain 2xl0 7 TCR yδ* T-cells with >98% purity. After three days in vitro without specific stimulation, the purified TCR yδ* T- ells were cultured with autologous GM-CSF- and IL-4- treated CDl + monocytes at a 1:1 ratio in 24 weU plates (Costar, Cambridge, MA) (plating 2X10 6 T-ceUs per weU). The antigen used to stimulate the ceUs was an organic extract of Mycobaaerium tuberculosis (as described in Examples 2 and 3) at a 1/3,750 dUution. Briefly, a chloroform/methanol extraction based on Folch's method, which partitions most lipids into the organic phase and protein into the aqueous phase and interface, was used. Recombinant Interieukin-2 (rIL-2) was added (0.3 nM) after 4 days of culture and the ceUs were restimulated with antigen every 12 days. Three rounds of stimulation led to the isolation of the CDlb-restricted TCR yδ* T-ceU line caUed OGD1. Although the purified TCR yδ* T-ceU population from which this T-ceU line was isolated predominantly expressed the Vδ2 gene product (90%), FACS analysis of OGD1 with the monoclonal antibody TCR δl (γ-TCR), δTCSl (Vδl gene product) and BB3 (Vδ2 gene product) (avaUable from T CeU Diagnostics, Cambridge, MA) demonstrated that the isolated T-ceUs expressed predominantly the Vδl gene product (Figure 26 A). This result suggests that this CDl mediated stimulation is UBSTIT different than all previous demonstrated examples of simulation of TCR γδ* T-cells by bacterial antigens, which invariably involve expansion of Vγ2Vό2 T-cells. The restriction of the OGDl ceU line by CDlb was confirmed using anti-CDlb monoclonal antibody which blocked cytotoxicity of antigen pulsed CDl'*' monocytes (Figure 27) and also blocked specific proliferation of the OGDl ceU line to mycobacterial antigens present in the organic phase of chloroform/methanol extracted mycobacteria (Figure 28). Further analysis of the fine specificity of this ceU Une demonstrated that OGDl recognized saponified cord factor (SIGMA, St. Louis, MO) (i.e., mycoUc acid, a Upid component of the mycobacterial cell waU) (Figure 28). CD8* TCR aβ* T-cells Recognize Antigens Presented by the CDl Molecule In order to determine if the CDl molecule could serve as an antigen presenting molecule for CD8 + TCR aβ* bearing T-ceUs, experiments similar to those described above were performed using purified peripheral blood CD8 + T-cells instead of TCR yδ* T-ceUs. T-ceUs were purified with magnetic beads conjugated with anti-CD8 monoclonal antibody (MUtenyi Biotec, Sunnyvale, CA) and purity was assessed by FACS after subsequent staining with FITC conjugated monoclonal antibody OKT8 (anti-CD8α). The culture protocol was simUar to that for TCR *γδ + T-cells. After three stimulations of these CD8 + T-cells with CDl* monocytes pulsed with the organic extract of Mycobaaerium tuberculosis, a ceU Une was obtained which was named OAB8. FACS analysis with FTTC-conjugated anti-CD8 α-chain (OKT8) and anti-CD8 /.-chain (2ST8-5H7) monoclonal antibodies showed that the cell Une was homogeneously positive for expression of the CD8 aβ heterodimer. Staining with TCR α/S-specific monoclonal antibody BMA031 showed that ceU line OAB8 was homogenously positive for TCR aβ. Proliferation assays confirmed the specificity of the OAB8 ceU line to the organic extract of mycobacteria and showed that OAB8 recognized purified SUBSTITUTE SHEET RULE 26 mycobacterial mycolic acid (Figure 29). Moreover, antibody blocking experiments demonstrated that the OAB8 cell line was restricted by the CDlc molecule (Figure 30), as anti-CD lc monoclonal antibody blocked its response whereas antibodies to CDla, CDlb and MHC class I molecules had no effect These data indicate that in addition to the reactivity of CD4 " 8 " TCR aβ* bearing T-cells to CDl-restricted microbial antigens, other major T-ceU populations are CDl restricted. Because CD8* TCR aβ* bearing T-cells account for approximately 35 % of aU circulating T-cells and TCR yδ bearing T-cells account for another 5% of aU T-cells, the potential magnitude of tiie CDl-restricted immune response is likely to be sigmficant in a variety of immunological response and syndromes. Moreover, since these T-cell populations are known to secrete an array of cytokines and to mediate cytolytic activity, the effector capabUities of CDl-restricted CD8 + TCR aβ* and TCR yδ* T-cells specific for nonpeptide antigens may play a critical role in host defense. Incorporation by Reference The entire text of all publications cited herein are entirely incorporated herein by reference.

Claims: What Is Claimed Is: 1. A method for detecting a CDl-presented lipoarabinomannan (LAM) antigen in a sample comprising the steps of: (a) contacting said sample with CD1+ cells; (b) contacting said CDl + ceUs with T-cells capable of binding a CDl presented LAM antigen; and (c) measuring a proliferative or cytolytic response of said T-ceUs corresponding to the presence of said CDl-presented LAM antigen in said sample. 2. A method according to claim 1, wherein said CD1 + cells are monocytes which have been contacted with a composition comprising at least one cytokine to induce CDl expression in said CD* cells. 3. A method according to claim 2, wherein said composition comprising at least one cytokine comprises at least one cytokine selected from interleukin-3, granulocyte macrophage colony stimulating factor and interleukin-4. 4. A method for isolating a CDl-presented LAM antigen from a sample, comprising the steps of: (a) incubating said sample with CDl + cells which bind said CDl-presented LAM antigen to generate CDl + ceUs displaying CDl- bound LAM antigen; (b) separating said CDl + cells- displaying said CDl-bound LAM antigen from said sample; and (c) isolating the CDl-presented LAM antigen from said CDl 4" cells displaying said LAM antigen. 5. A method for isolating a CDl-presented LAM antigen from a biological sample, comprising the steps of: (a) fractionating a sample containing a CDl-presented LAM antigen to generate at least two fractions; (b) testing said fractions for the ability to generate a proliferative or cytolytic response with a T-ceU, wherein said proliferative or cytolytic response indicates that CDl-presented LAM antigen is present in the tested fraction; and (c) isolating the CDl-presented LAM antigen from the fractions that generate a proliferative or cytolytic response. 6. A method according to claim 5, wherein said testing step (b) comprises the substeps of: (i) contacting said sample with CDl 4" cells; (U) contacting said CD1 + ceUs with T-cells capable of binding a CDl presented LAM antigen; and (in) measuring a proliferative or cytolytic response of said T-ceUs corresponding to the presence of said CD-I presented LAM antigen in said sample. 7. An isolated CDl-presented LAM antigen produced by a method according to claim 4. 8. An isolated CDl-presented LAM antigen produced by a method according to claim 5. 9. A method for detecting a CDl blocking agent in a sample, comprising the steps of: (a) assaying a control sample by a method comprising the steps of -75- (1) contacting said sample with CDl 4" ceUs and CDl-presented LAM antigen; (2) contacting said CDl 4* cells with T-cells capable of binding a CDl presented LAM antigen; and (3) measuring a proliferative or cytolytic response of said T-cells; and (b) assaying a sample suspected of containing a CDl blocking agent by a method comprising the steps of (1') contacting said sample with CDl 4" cells and CDl-presented LAM antigen; (2') contacting said CD1 + cells with T-cells capable of binding a CDl presented LAM antigen; and (3*) measuring a proliferative or cytolytic response of said T-cells; and (c) comparing the proliferative or cytolytic response of step (a) to that of step (b), wherein a reduced proliferative or cytolytic response of step (b), compared to the proliferative or cytolytic response of step (a), correlates with the presence of a CDl blocking agent in the sample of step (b). 10. A CDl blocking agent which inhibits CDl-restricted LAM antigen presentation, said agent comprising a member selected from the group consisting of an antibody, a synthetic polypeptide, an inhibitor of CDl- restricted LAM antigen presentation, and an antigen antagonist derived from a CDl-presented LAM antigen. 11. A method for inhibiting CDl-restricted LAM antigen presentation by CDl 4" cells, comprising the step of: contacting cells displaying a CDl molecule with a CDl blocking agent according to claim 10. 12. A method according to claim 11, wherein said antibody binds to said CDl molecule and blocks the interaction of said CDl molecule with a CDl-restricted LAM antigen, said antibody being supplied in an amount sufficient so as to inhibit the binding of said CDl molecule to said CD1- restricted LAM antigen. 13. A method according to claim 11, wherein said synthetic polypeptide is derived from a variable region of a TCR α or β molecule which binds to a CDl-bound LAM antigen and blocks the interaction of a TCR molecule with a CDl-bound LAM antigen, said polypeptide being supplied in an amount sufficient so as to inhibit the binding of said TCR molecule to said CDl-bound LAM antigen. 14. A method according to claim 11, wherein said antigen antagonist is derived from a CDl-presented LAM antigen and blocks the interaction of said CDl molecule with a CDl-restricted LAM antigen, said antigen antagonist being supplied in an amount sufficient so as to inhibit the binding of said CDl molecule to said CDl-restricted LAM antigen. 15. A vaccine, comprising a CDl-presented LAM antigen or a synthetic derivative of a CDl-presented LAM antigen. 16. A vaccine according to claim 15, further comprising: a CDl molecule selected from the group consisting of CDla, CDlb, CDlc, CDld and CDle, wherein said vaccine comprises an antige CDl complex. 17. A vaccine according to claim 15 , further comprising at least one non-CD 1 presented antigen. 18. A vaccine according to claim 15, wherein said non-CD 1 presented antigen is selected from an MHC-I presented antigen or an MHC-U presented antigen. 19. A method for producing a vaccine containing a CDl-presented LAM antigen comprising the step of: formulating an isolated CDl-presented LAM antigen according to claim 7 so as to form a vaccine. 20. A method for producing a vaccine containing a CDl-presented LAM antigen comprising the step of: formulating an isolated CDl-presented LAM antigen according to claim 8 so as to form a vaccine. 21. A vaccine comprising a CDl-presented LAM antigen produced a method according to claim 19. 22. A vaccine comprising a CDl-presented LAM antigen produced a method according to claim 20. 23. A method for vaccination, comprising the step of: administering a vaccine according to claim 15 in an amount effective to provide an immune response to said antigen in a bird or mammal. 24. A method according to claim 23, wherein said vaccine is administered orally or parenteraUy. 25. An isolated T-ceU that recognizes a CDl-presented LAM antigen, wherein εaid CDl-presented LAM antigen comprises a LAM portion of a lipid. 26. A T-cell according to claim 25, wherein said CDl-presented LAM antigen is presented by a CDl molecule selected from the group consisting of CDla, CDlb, CDlc. CDld and CDle. 27. A T-ceU according to claim 25, wherein said CDl-presented LAM antigen is isolated from a Mycobacterial species selected from the group consisting of M. tuberculosis, M. bovis, M. leprae, M. fortuitum and M. avium. 28. A method for providing a T-cell according to claim 25, comprising the steps of: (a) purifying T-cells which are capable of binding a CDl- presented LAM antigen from a sample containing T-cells; (b) incubating a mycobacterium with CD1 + cells which bind said CDl-presented LAM antigen to generate CD1 + ceUs displaying said CDl-presented LAM antigen; (c) contacting the CD1 + cells displaying said CDl- presented LAM antigen of (b) with the T-cells of (a); and (d) isolating T-cells that recognize an isolated CDl- presented LAM antigen and give a proUferative response during step (c), wherein said proliferative response does not occur in the presence of antibodies to CDl. -79- 29. A vaccine, comprising a CDl-presented lipid or glycolipid antigen or its functional equivalent. 30. A vaccine according to Claim 29, wherein the antigen is a ceUular component of an organism. 31. A vaccine according to Claim 29, wherein the antigen is derived from a bacterial, fungal, or protozoan ceU. 32. A vaccine according to Claim 29, further comprising an adjuvant or a pharmaceuticaUy acceptable carrier. 33. A vaccine according to Claim 29, further comprising one or more different antigens. 34. A method for enhancing or accelerating the immunity of a vertebrate which comprises administering to the vertebrate an effective immunizing amount of a vaccine comprising a CDl-presented hydrophobic antigen or its functional equivalent.

Inventors: BRENNAN PATRICK J, BRENNER MICHAEL B, FURLONG STEPHEN T, MODLIN ROBERT L, PORCELLI STEVEN A, SIELING PETER A, BRENNAN, PATRICK, J., BRENNER, MICHAEL, B., FURLONG, STEPHEN, T., MODLIN, ROBERT, L., PORCELLI, STEVEN, A., SIELING, PETER, A.
Applicants: BRENNAN PATRICK J, BRENNER MICHAEL B, BRIGHAM & WOMENS HOSPITAL, FURLONG STEPHEN T, MODLIN ROBERT L, PORCELLI STEVEN A, SIELING PETER A, UNIV CALIFORNIA LOS ANGELES, UNIV COLORADO RES, BRENNAN, PATRICK, J., BRENNER, MICHAEL, B., BRIGHAM & WOMEN'S HOSPITAL, FURLONG, STEPHEN, T., MODLIN, ROBERT, L., PORCELLI, STEVEN, A., SIELING, PETER, A., THE COLORADO STATE UNIVERSITY RESEARCH FOUNDATION, THE UNIVERSITY OF CALIFORNIA, LOS ANGELES
Application year: 1995
Main classification: G01N33
IPC codes: A61K39, A61K47, C07K14, C07K16, C08B37, C12N5, C12P19, C12Q1, G01N33