title: Serological inhibition of blast transformation to purified streptococcal antigens by planned immunization in HLA (A,B) compatible unrelated individuals.
abstract: Sera obtained from planned immunizations between unrelated donors and recipients, identical or compatible at HLA-A and B, were assessed for their capacity to alter the in vitro response of a test panel of lymphocytes to PHA and a purified streptococcal antigen (PAS). In the case of PHA, no serum effects were apparent. The response to PAS, however, significantly inhibited by two sera. When tested for their complement-dependent cytotoxicity on enriched populations of T and B lymphocytes, none of the sera manifested cytotoxicity against T cells nor did serological inhibition correlate with the capacity to lyze B cells. The data suggest that inhibition of the PSA response is mediated by blocking antibodies specific for a subset of lymphocytes, possibly T cells. While the precise mechanism governing the response to PSA is not known, the data are compatible with the idea that an HLA-linked Ir gene, expressed on a subset of T lymphocytes, controls immune responsiveness to PSA.
mesh_terms: D000918:Antibody Specificity; D000942:Antigens, Bacterial; D001402:B-Lymphocytes / Q000276:immunology; D003601:Cytotoxicity Tests, Immunologic; D005802:Genes, MHC Class II; D006680:HLA Antigens; D006801:Humans; D007518:Isoantibodies; D037102:Lectins / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects; D013291:Streptococcus / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D006680:HLA Antigens; D007518:Isoantibodies; D037102:Lectins