The superantigen exfoliative toxin induces cutaneous lymphocyte-associated antigen expression in peripheral human T lymphocytes

Abstract

Several immune-mediated dermatoses including psoriasis and atopic dermatitis can be exacerbated by bacterial infections. Superantigen producing bacteria can be isolated from skin lesions of these dermatoses. Consistent with superantigen effects, skewed T cell receptor variable gene usage has been demonstrated within these lesions. Therefore, the question arises whether superantigens induce a skin-seeking phenotype within peripheral T cells. In this study, we investigated the in vitro influence of the Vβ2-selective superantigen exfoliative toxin from Staphylococcus aureus on the expression of the cutaneous lymphocyte-associated antigen on peripheral T lymphocytes of healthy donors. We demonstrate that exfoliative toxin dramatically upregulates cutaneous lymphocyte-associated antigen expression on T cell receptor Vβ2 + lymphocytes. Up to 69% of Vβ2 + lymphocytes expressed cutaneous lymphocyte-associated antigen after 5 days of in vitro culture. Additionally, exfoliative toxin also increased cutaneous lymphocyte-associated antigen expression in CD3 + T cell receptor Vβ2 − lymphocytes indicating a different effect as caused by the superantigen-T cell receptor Vβ2 interaction. Our findings suggest influence of bacterial superantigens on T lymphocyte skin homing in vivo.