Distinct T-cell receptor Vβ gene usage by human T lymphocytes stimulated with the streptococcal pyrogenic exotoxins and pep M5 protein

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 Vβ 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 Vβ 2, 4, and 8 elements of the T-cell receptor (TCR), whereas SPE A stimulates TCR Vβ 2-, 12-, 14-, and 15-bearing cells. SPE B stimulated only cells expressing TCR Vβ 8 elements, while SPE C stimulated cells expressing Vβ 1, 2, 5.1, and 10. These studies reveal that the preferential usage of particular Vβ elements is distinct for these different superantigens, which may be important in the pathogenesis of various streptococcal diseases.