Synergistic immunopotentiating effects induced by T-cell and B-cell superantigen in mice

Staphylococcal Enterotoxin-A(SEA), a 27 kDa monomeric protein, produced by some strains of Staphylococcus aureus, is a prototype T-cell superantigen w hich causes proliferation or cytotoxic T-lymphocytes and produces cytokines like TNF-alpha and IFN-gamma. Recently Protein A (PA), a 42 kDa membrane p rotein of the Staphylococcus aureus Cowan-I strain, has been termed a B-cel l super antigen. It has been shown to cause multiple immunological response s. In the present study we examined the effect of these two superantigens u sed separately as well as combination in a normal mouse system. It has been shown that combination treatment of PA and SEA is more effective than that of each individual one. FACS analyses of cell cycles showed that a finely turned cellular collaboration occurred in various phases of cell growth and proliferative response compared with controls (P<0.01). It has also been s hown that the percentage of various cell types bearing different clusters o f differentiation markers, e.g., CD8(+), CD34(+) increases considerably due to the combined effect of PA and SEA. We also observed that co-administrat ion of both the elicits different soluble mediators like cytokines (TNF-<al pha>, INF-gamma, IL-1 beta). No apoptotic phenomenon was observed (from the cell cycle analysis) for the dose of PA and SEA. used for the experiments, suggesting that these doses of PA and SEA should be non-toxic.