title: Antigen-specific suppressor T lymphocytes (Leu-2a+3a-) in human schistosomiasis japonica.
abstract: Immunoregulatory mechanisms in human schistosomiasis japonica were investigated through in vitro T lymphocyte-macrophage co-culture experiments. High responder T lymphocytes responded to the schistosomal adult worm antigen in the presence of HLA-DR-compatible low responder macrophages, whereas low responder T lymphocytes failed to respond to this antigen even in the presence of HLA-DR-compatible high responder macrophages. This observation strongly suggested that T lymphocytes, but not macrophages, controlled the low responsiveness to the schistosomal adult worm antigen. When high responder lymphocytes were challenged with the schistosomal antigen in the presence of low responder T lymphocytes, low responder T lymphocytes caused an antigen-specific suppression, in a dose-dependent manner, of the responsiveness of high responder lymphocytes. The suppressor T lymphocytes were mitomycin C resistant and were positive for Leu-2a, but were negative for Leu-3a. When Leu-2a+ T lymphocytes were depleted from low responder T lymphocytes, a vigorous response by the Leu-2a-depleted T lymphocytes (Leu-2a-3a+) to the schistosomal adult worm antigen was observed. By adding back the Leu-2a+ T lymphocytes into autologous T lymphocyte subpopulations, the specific response to the adult worm antigen was completely suppressed. These findings clearly demonstrate the existence of Leu-2a+3a- suppressor T lymphocytes that can control low responsiveness to the schistosomal adult worm antigen in man.
mesh_terms: D000328:Adult; D000941:Antigens / Q000032:analysis* / Q000276:immunology; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis / Q000276:immunology; D004306:Dose-Response Relationship, Immunologic; D000939:Epitopes / Q000276:immunology*; D005260:Female; D006801:Humans; D008211:Lymphocyte Cooperation; D008264:Macrophages / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012549:Schistosoma japonicum / Q000276:immunology; D012552:Schistosomiasis / Q000276:immunology* / Q000469:parasitology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D000941:Antigens; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D000939:Epitopes