Increased expression of interleukin-1 receptors on fibroblasts derived from inflamed gingiva.

We investigated the expression of interleukin-1 receptors (IL-1R) on the surfaces of cultured gingival fibroblasts derived from healthy and inflamed gingiva and the effects of IL-1 alpha and IL-1 beta and prostaglandin E2 (PGE2) on IL-1R expression. Fibroblasts were obtained from explant culture of both healthy and inflamed gingiva. IL-1R on cell surfaces was detected immunohistochemically using an anti-human IL-1R monoclonal antibody. IL-1R expression was assessed quantitatively using an enzyme linked immunosorbent assay (ELISA). Positive staining for IL-1R was more evident on cells from inflamed gingiva compared with cells from healthy gingiva. The ELISA showed a significantly increased number of IL-1R on cells from inflamed gingiva compared with cells from healthy gingiva (P < 0.05). Treatment with IL-1 but not PGE2 increased expression of IL-1R on fibroblasts. These findings suggest that gingival fibroblast responses to IL-1 may represent a mechanism for amplification of gingival inflammation.