effects of different mediators on fibroblast proliferation

in this study, we have investigated the proliferative response of human dermal fibroblasts isolated from normal and psoriatic individuals to different cytokines. we found that il-1, tnf (α) and egf are stimulatory whereas ifn « and 1 both showed inhibitory activity on fibroblast proliferation. il-6 a more recently described cytokine, showed no detectable effects on cell proliferation. investigating the combined effects of these mediators on fibroblasts, we found that while eg f has additive effects on il-1 ortnf (α) activated cells, both ifns showed suppressive activity on the cell proliferation. there was no statistical difference in proliferative response of fibroblasts isolated from normal and psoriatic individuals. the significance of these findings is discussed,