title: Anti-class II antibodies in AIDS patients and AIDS-risk groups.
abstract: The specificity of anti-lymphocyte antibodies was evaluated in AIDS patients and in individuals at risk of AIDS [R-AIDS: male homosexuals (Ho) and haemophiliacs (He)]. Antibodies capable of inducing antibody-dependent cell-mediated cytotoxicity (ADCC) against non-T cells and lymphoblastoid cell lines (P3HR-1K and Raji) were detected in AIDS patients and in R-AIDS with positive or negative human immune deficiency virus (HIV) serology. Anti-class II antigen specificity was revealed by experiments in which class II antigens on target cells were blocked with monoclonal anti-class II antibody (DA6,231) and the cytotoxic reaction induced by patient's sera was abolished. In contrast, ADCC was not impaired by preincubating the target cells with anti-class I monoclonal antibody (W6/32). Prevalence of antibodies to non-T cells was confirmed by standard C-mediated microlymphocytotoxicity. However, with this technique anti-T lymphocyte cytotoxicity was also observed in three AIDS patients with haemophilia. R-AIDS peripheral blood mononuclear cells (PBMC) were also cytotoxic against autologous non-T cells, and lysis was slightly increased by sensitization of the target cells with autologous serum. In addition to ADCC and C-mediated cytotoxicity, the specificity of anti-lymphocyte antibodies was assayed by their ability to interfere the binding of fluorescein-labelled anti-class II (HLA-DR) and anti-class I (W6/32) monoclonal antibodies to PBMC, non-T cells, P3HR-1K and Raji. Anti-class II specificity was confirmed, and antibody titres tended to be higher in Ho than in He R-AIDS, using non-T cells and Raji as targets. Higher titres of anti-class II antibodies in the Ho group could play a role in the different susceptibility of HIV-infected Ho when compared to HIV (+) He to develop AIDS.
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology*; D000918:Antibody Specificity; D000920:Antibody-Dependent Cell Cytotoxicity; D000961:Antilymphocyte Serum / Q000032:analysis*; D003602:Cytotoxicity, Immunologic; D006681:HLA-D Antigens / Q000276:immunology*; D006467:Hemophilia A / Q000276:immunology; D006716:Homosexuality; D006801:Humans; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D012307:Risk Factors; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000961:Antilymphocyte Serum; D006681:HLA-D Antigens