title: T cell subsets in leprosy lesions: in situ characterization using monoclonal antibodies.
abstract: Cryostat sections of dermal lesions from 30 untreated leprosy patients were studied by indirect immunofluorescence using monoclonal antibodies defining T cell subsets and Ia like antigens. Most lymphocytes in leprosy lesions were positive for OKT3 and Ia like antigens indicating thereby the presence of activated T cells. Maximal numbers of these cells were seen in localized paucibacillary tuberculoid leprosy lesions in close association with epithelioid cells. A decline in their numbers was observed over the leprosy spectrum with a marked reduction in disseminated, multi-bacillary, lepromatous leprosy where only scattered OKT3+ cells were visualized. OKT4 and OKT8 positive cells defining T cell subsets, were frequently found within the OKT3+ lymphocytes throughout the leprosy spectrum. The ratio of OKT4+/OKT8+ cells ranged from 1.2 to 5.0 in tuberculoid and from 0.2 to 1.0 in lepromatous lesions. Macrophages in the granulomas stained intensely with anti-Ia antisera. Ia like antigens were expressed to the same degree on macrophages with or without intracellular acid fast bacilli.
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D005455:Fluorescent Antibody Technique; D006099:Granuloma / Q000276:immunology / Q000473:pathology; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D007918:Leprosy / Q000276:immunology* / Q000473:pathology; D007958:Leukocyte Count; D010586:Phagocytes / Q000276:immunology; D012867:Skin / Q000276:immunology* / Q000473:pathology; D013601:T-Lymphocytes / Q000145:classification* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000949:Histocompatibility Antigens Class II