Selective stimulation of human T cells with streptococcal erythrogenic toxins A and B

• Published in: The Journal of immunology (1950) Vol. 146; no. 11; pp. 3747 - 3750
• Main Authors: Abe, J, Forrester, J, Nakahara, T, Lafferty, JA, Kotzin, BL, Leung, DY
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Assoc Immnol 01.06.1991; American Association of Immunologists
• Subjects: Analysis of the immune response. Humoral and cellular immunity; Animals; Antigens, Differentiation, T-Lymphocyte - analysis; Bacterial Proteins; Biological and medical sciences; CD4 Antigens - analysis; CD8 Antigens; Enterotoxins - pharmacology; Exotoxins - pharmacology; Fundamental and applied biological sciences. Psychology; Fundamental immunology; HLA-DR Antigens - analysis; Humans; Immunobiology; Lymphocyte Activation - drug effects; Membrane Proteins; Mice; Organs and cells involved in the immune response; Pyrogens - pharmacology; Receptors, Antigen, T-Cell - genetics; Streptococcus pyogenes; T-Lymphocytes - drug effects; T-Lymphocytes - immunology; Human; Streptococcaceae; Toxin; T cell receptor; T-Lymphocyte; Bacteria; Micrococcales; Stimulation; Streptococcus pyogenes; Exotoxin; Cell subpopulation
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.146.11.3747

Streptococcal exotoxins have been implicated in the pathogenesis of a toxic shock-like syndrome and scarlet fever. Previous studies have demonstrated that these toxins are potent stimulators of human T cells and have structural homology to staphylococcal enterotoxins. In the current study, we investigated the mechanism by which streptococcal erythrogenic toxins type A (SPEA) and B (SPEB) activate T cells and compared it with anti-CD3 and the known "superantigen" staphylococcal enterotoxin B. SPEA was found to selectively activate T cells bearing V beta 8, V beta 12, and V beta 14, whereas SPEB selectively activated T cells bearing V beta 2 and V beta 8. Furthermore, fibroblasts transfected with MHC class II molecules were capable of presenting SPEA and SPEB to purified T cells. The T cell response to these toxins, however, was not MHC-restricted. Although the streptococcal exotoxins stimulated both CD4+ and CD8+ T cells, SPEA but not SPEB stimulated the CD4+ T cell subset proportionately more than the CD8+ T cell subset. Our results indicate that SPEA and SPEB, like the staphylococcal enterotoxins, are superantigens and suggest a mechanism by which they may mediate particular systemic syndromes associated with streptococcal infections.