AUTOLOGOUS VERSUS ALLOGENEIC T-CELL-STIMULATED IL-6 PRODUCTION BY DERMAL FIBROBLASTS

T cells adhere to human dermal fibroblasts (HDF). This cellular intera ction leads to a pronounced secretion of the proinflammatory cytokines IL-6 and IL-8 via a juxtacrine stimulation induced by HDF-associated IL-1. Upon stimulation, fibroblasts express various surface proteins s uch as MCH-I molecules, which may interact with corresponding receptor s on T cells. The present study was conducted to further investigate t he mechanism of this complex interaction with regard to the secretion of IL-6 in cocultures of T cells and HDF. IL-6 was time-and dose-depen dently upregulated in such cocultures. Spatial separation of the cells by microporous membranes resulted in a 90% reduction of IL-6 secretio n, but when cells had limited cell contact IL-6 secretion was increase d again. Allogeneic cocultures of T cells and HDF showed increased cap acity of IL-6 stimulation as compared to autologous cultures. Our resu lts suggest that MHC-I/T cell receptor interaction modulates IL-6 secr etion in allogeneic and autologous cocultures.