POSSIBLE ROLE OF CYTOKINES IN CELLULAR PROLIFERATION OF THE SKIN TRANSPLANTED ONTO NUDE-MICE

Background and Design: In recent studies on the behavior of aged skin transplanted onto nude mice, the epidermis of aged and young skin show ed an increase in proliferation and thickness following engraftment, a nd became almost identical. The aim of this study was to ascertain a p ossible role for the release of local cytokines in this phenomenon. Gr afted human skin was injected intradermally with anti-interleukin-6 (I L) and anti-IL-1 alpha, and comparisons of epidermal thymidine incorpo ration and thickness were made. Grafts injected with irrelevant antibo dies served as control. Results: Interleukin-6 and IL-1 alpha expressi on were studied in grafts by immunoperoxidase staining. Only IL-6 expr ession was found in the 1-month grafts. Intradermal injections of anti -IL-1 alpha and anti-IL-6 showed an inhibitory effect on cellular prol iferation in the epidermis, A significant difference in the response o f epidermal proliferation and, consequently, in thickness was found in samples injected with anti-IL-1 alpha and anti-IL-6 compared with tho se injected with irrelevant antibodies. Conclusions: These data may in dicate that local cytokines released by the keratinocytes are involved in the cellular proliferative activity in skin engrafted onto the mic e.