High affinity of interaction between superantigen and T cell receptor Vbeta molecules induces a high level and prolonged expansion of superantigen-reactive CD4+ T cells.

ABSTRACT: In mice implanted with an osmotic pump filled with the superantigen (SAG) staphylococcal enterotoxin A (SEA), the V?3(+)CD4(+) T cells exhibited a high level of expansion whereas the V?11(+)CD4(+) T cells exhibited a mild level of expansion. In contrast, in mice implanted with an osmotic pump filled with SE-like type P (SElP, 78.1% homologous with SEA), the V?11(+)CD4(+) T cells exhibited a high level of expansion while the V?3(+)CD4(+) T cells exhibited a low level of expansion, suggesting that the level of the SAG-induced response is determined by the affinities between the TCR V? molecules and SAG. Analyses using several hybrids of SEA and SElP showed that residue 206 of SEA determines the response levels of V?3(+)CD4(+) and V?11(+)CD4(+) T cells both in vitro and in vivo. Analyses using the above-mentioned hybrids showed that the binding affinities between SEA and the V?3/V?11 ? chains and between SEA-MHC class II-molecule complex and V?3(+)/V?11(+) CD4(+) T cells determines the response levels of the SAG-reactive T cells both in vitro and in vivo.

SUBMITTER: Omoe K 

PROVIDER: S-EPMC2945535 | biostudies-literature | 2010 Oct

REPOSITORIES: biostudies-literature