title: Anti-Ia reactivity in sera from subjects with Entamoeba histolytica infection.
abstract: Sera from 15 patients with Entamoeba histolytica infection were tested for anti T-cell antibodies by assessing cross-reacting specificities with the antigens defined by an anti-Ia hybridoma antibody. T cells prepared by sheep erythrocyte rosetting were preincubated with the test sera and then with the anti-Ia antibody. Binding of the specific monoclonal antibody was assessed by rosetting with ox erythrocytes conjugated with goat anti-mouse IgG. Eight sera from amoebic patients were found to block the binding of monoclonal mouse hybridoma anti Ia-antibody to T cells. Blocking of anti-Ia binding was not due to Fc IgG receptor binding by immune complexes nor was it HLA-DR restricted. T cells pre-treatment with the amoebic sera positive for anti-Ia activity showed reduced activity when tested in the autologous mixed lymphocyte reaction (AMLR). The results of our study seem to suggest the existence of specific anomalies of immunoregulation during E. histolytica infection which may play a role in inducing immune disregulation in vivo.
mesh_terms: D000328:Adult; D000562:Amebiasis / Q000276:immunology*; D000906:Antibodies / Q000032:analysis*; D000911:Antibodies, Monoclonal / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D004748:Entamoeba histolytica / Q000276:immunology; D004749:Entamoebiasis / Q000276:immunology*; D000939:Epitopes; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D007959:Lymphocyte Culture Test, Mixed; D008297:Male; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000906:Antibodies; D000911:Antibodies, Monoclonal; D000939:Epitopes; D000949:Histocompatibility Antigens Class II