THE SUPERANTIGEN EXFOLIATIVE TOXIN INDUCES CUTANEOUS LYMPHOCYTE-ASSOCIATED ANTIGEN EXPRESSION IN PERIPHERAL HUMAN T-LYMPHOCYTES

Several immune-mediated dermatoses including psoriasis and atopic derm atitis can be exacerbated by bacterial infections. Superantigen produc ing bacteria can be isolated from skin lesions of these dermatoses. Co nsistent with superantigen effects, skewed T cell receptor variable ge ne usage has been demonstrated within these lesions. Therefore, the qu estion arises whether superantigens induce a skin-seeking phenotype wi thin peripheral T cells. In this study, we investigated the in vitro i nfluence of the V beta 2-selective superantigen exfoliative toxin from Staphylococcus aureus on the expression of the cutaneous lymphocyte-a ssociated antigen on peripheral T lymphocytes of healthy donors. We de monstrate that exfoliative toxin dramatically upregulates cutaneous ly mphocyte-associated antigen expression on T cell receptor V beta 2(+) lymphocytes. Up to 69% of V beta 2(+) lymphocytes expressed cutaneous lymphocyte-associated antigen after 5 days of in vitro culture. Additi onally, exfoliative toxin also increased cutaneous lymphocyte-associat ed antigen expression in CD3(+) T cell receptor V beta 2(-) lymphocyte s indicating a different effect as caused by the superantigen-T cell r eceptor V beta 2 interaction. Our findings suggest influence of bacter ial superantigens on T lymphocyte skin homing in vivo.