Skewed T cell receptor V alpha repertoire among superantigen reactive murine T cells

Reactivity of murine T cells with viral or bacterial superantigens is clearly correlated with the expression of TCR V beta domains. Thus, T cells responding to the minor lymphocyte stimulatory locus (Mls-1a) or staphylococcal enterotoxin B (SEB) express predominantly TCR V beta 6 or V beta 8.2 respectively. We have investigated the involvement of the other major variable element of the TCR, the V alpha domain, in these superantigen responses. Using a panel of anti-TCR V alpha mAbs, it is demonstrated that the TCR V alpha repertoire among superantigen stimulated V beta 6+ or V beta 8.2+ blasts (responding to Mls-1a or SEB respectively in vitro) is altered in comparison with anti-CD3 stimulated cells expressing the same V beta domains. Furthermore, the TCR V alpha repertoire is strongly skewed in TCR V beta 8.2 transgenic mice that have undergone extensive peripheral clonal deletion after SEB injection. These data imply that the V alpha domain influences superantigen recognition by the TCR.