Analysis of human T cell responses to group A streptococci using fractionatedStreptococcus pyogenesproteins

摘要: Cell extract and spent culture supernatant proteins from Streptococcus pyogenes Manfredo strain (type M5) were each separated to give 22 narrow range molecular weight fractions by blot-elution SDS-polyacrylamide gels. Eluted samples unfractionated screened for T cell stimulatory activity using human peripheral blood mononuclear cells (PBMC) healthy adults in proliferation assays. Responses measured 4- 7d cultures. a wide of revealed fractionation, the degree response fraction varying between donors. Unfractionated elicited proliferative responses PBMC all individuals examined. containing 25–33 kDa could be attributed known superantigens. Furthermore, supernatants higher (>45 kDa) 50% donors cultures, suggesting that these contained common recall antigens. The efficacy electroeluted identify lymphocyte was confirmed demonstrating superantigen S. strain, streptococcal pyrogenic exotoxin C (SPEC), fractionated successfully this method its recovered. Our results show group A streptococci involve remarkably both cell-associated released proteins.