Effects on murine T helper cell proliferation by DTH activated syngeneic epidermal cells.

Epidermal cells, obtained either from the site of a delayed type of hypersensitivity (DTH) reaction to 2,4-dinitro-1-fluorobenzene (DNFB) or from skin subjected only to painting with acetone: olive oil have been studied for their capacity to stimulate antigen specific T-lymphocyte proliferation. Small numbers of cells from the control, as well as from the DTH activated epidermis, presented collagen type II to a line of and a clone of collagen II specific T helper cells. Larger numbers of epidermal cells from DTH activated epidermis suppressed this T-cell proliferation compared to control epidermal cells. Phenotypic analysis showed an increased expression of Thy-1 antigen on epidermal cells from DTH lesions 3 days after provocation. It is suggested that epidermal cells may be involved in negative as well as positive feedback loops in conjunction with T-cell immunity. It would thus be of interest to study further whether the induced Thy-1 antigen expression on epidermal cells is of importance in a negative feedback system.