T cells involved in psoriasis vulgaris belong to the Th1 subset

Although the pathogenesis of psoriasis vulgaris is still unknown, several characteristics point to an immunologically mediated process. Epidermal psoriatic lesions are characterized by a hyperproliferation of keratinocytes and an infiltration of T lymphocytes and granulocytes. Because the former may be mediated in part by lymphokines secreted by T cells, we have focused our interest on the in vivo and in vitro cytokine secretion patterns of T lymphocytes from psoriatic lesions. In five patients T lymphocytes were obtained from epidermal specimens. The cells were propagated with lectin and irradiated feeder cells and subsequently cloned by limiting dilution. The resulting T-cell clones were …