title: In situ identification of cells in human leprosy granulomas with monoclonal antibodies to interleukin 2 and its receptor.
abstract: Leprosy is a chronic granulomatous disease with an immunologic spectrum in which lepromatous leprosy patients have defective cell-mediated immune responses, in comparison to tuberculoid leprosy patients. Immunoregulatory aspects of this spectrum were investigated by using monoclonal antibodies to interleukin 2 (IL 2), IL 2 receptors (Tac), and T lymphocyte subpopulations with immunoperoxidase techniques on frozen sections of skin biopsy specimens from 10 tuberculoid and 10 lepromatous patients. A comparison of IL 2+ cells revealed markedly fewer IL 2+ cells in lepromatous specimens (lep. 0.028% +/- 0.02 vs tub. 0.46% +/- 0.28, p less than 0.001). These IL 2+ cells were large, exhibited cytoplasmic staining, and on double immunostaining were Leu-4+, Leu-3a+, Leu-2a-, Tac-, and OKT6-, consistent with the fact they are IL 2 producers. Equivalent numbers of Tac+ cells were observed in both lepromatous and tuberculoid granulomas (lep. 1.5% +/- 0.5 vs tub. 2.1% +/- 0.7, p, NS), suggesting that the responder cells are present in both conditions. The tuberculoid granuloma was highly organized, composed of a central core of mature macrophages, Leu-3a+ and Tac+ cells with a surrounding mantle of Leu-2a+, Leu-3a+, IL 2+, Tac+, and OKT6+ cells. In lepromatous granulomas, Leu-2a+, Leu-3a+, Tac+, and rare IL 2+ cells were randomly admixed with bacilli-laden macrophages. The defective cell-mediated immune responses in lepromatous leprosy appears to be associated with diminished IL 2 production and disorganization of the granuloma.
mesh_terms: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000276:immunology; D006099:Granuloma / Q000276:immunology* / Q000378:metabolism; D006651:Histocytochemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D007376:Interleukin-2 / Q000096:biosynthesis / Q000276:immunology*; D007918:Leprosy / Q000276:immunology* / Q000378:metabolism; D011971:Receptors, Immunologic / Q000276:immunology*; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology / Q000378:metabolism; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
chemical_list: D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D007376:Interleukin-2; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7