Staphylococcal enterotoxins are potent superantigens, in that they activate T cells bearing specific Vβ-chain gene segments. In this study, we analyzed the capacity of staphylococcal enterotoxin D (SED) to function as a B cell superantigen. SED induced T cell-dependent polyclonal proliferation and differentiation of B cells. In the absence of T cells, SED induced survival of B cells uniquely expressing VH4 containing IgM. The mechanism of survival of VH4-expressing B cells appeared to relate to the countering of apoptosis initiated by the engagement of HLA-DR by SED. Analysis of the VH4 gene products expressed by SED-stimulated B cells revealed the usage of six of the known functional VH4 genes with a variety of different CDR3 regions, employing different DH and JH gene segments. Moreover, the sequence analysis identified a possible site for SED binding of VH4 that includes the solvent-exposed surfaces of 3′ CDR2/FR3 and/or FR1. Thus, SED appears to function as a unique B cell superantigen by inducing survival of VH4-expressing B cells.
|Original language||English (US)|
|Number of pages||13|
|Journal||Journal of Immunology|
|State||Published - May 15 1996|
ASJC Scopus subject areas
- Immunology and Allergy