title: Immunoregulatory activities of autoreactive T cells: an I-A-specific T cell clone mediates both help and suppression of antibody responses.
abstract: We have derived a Ly-1+, 2-3- T cell clone that is specific for autologous I-A on activated but not on resting cells. After activation, this clone produces factors that induce purified (B + adherent) cells to secrete antibody in response to sheep red blood cells and type 2 T-independent antigens. Regulation of plaque-forming cell responses by this clone is dose dependent: low numbers enhance the plaque-forming cell response, whereas high numbers suppress the response. The inhibition observed with high doses is associated with cytolysis of I-A+ cells, and this can be blocked by the addition of anti-I-A antibodies. The physiologic significance of this novel cell type in regulating immune responses is discussed.
mesh_terms: D000818:Animals; D000921:Antibody-Producing Cells / Q000276:immunology; D000961:Antilymphocyte Serum / Q000494:pharmacology; D001402:B-Lymphocytes / Q000276:immunology; D001667:Binding, Competitive; D002999:Clone Cells / Q000276:immunology / Q000528:radiation effects; D004306:Dose-Response Relationship, Immunologic; D000939:Epitopes; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000528:radiation effects
chemical_list: D000961:Antilymphocyte Serum; D000939:Epitopes; D000949:Histocompatibility Antigens Class II