ABSTRACT
A number of streptococcal products, including the streptococcal pyrogenic exotoxin (SPE) types A, B, and C as well as a 22-kDa fragment of M type 5 protein (pep M5), are potent stimulants of human T-lymphocyte blastogenesis and belong to the newly designated family of superantigens. The V beta usage of human T cells stimulated with these toxins was investigated by using the polymerase chain reaction. We demonstrate that SPE A, B, and C as well as pep M5 stimulate the proliferation of T cells in a dose-dependent manner. pep M5 stimulates cells bearing V beta 2, 4, and 8 elements of the T-cell receptor (TCR), whereas SPE A stimulates TCR V beta 2-, 12-, 14-, and 15-bearing cells. SPE B stimulated only cells expressing TCR V beta 8 elements, while SPE C stimulated cells expressing V beta 1, 2, 5.1, and 10. These studies reveal that the preferential usage of particular V beta elements is distinct for these different superantigens, which may be important in the pathogenesis of various streptococcal diseases.
