Transforming growth factor-beta isoforms regulate the surface expression on membrane cofactor protein (CD46) and CD59 on human keratinocytes

We studied the regulation of the expression of complement regulatory protei ns, membrane cofactor protein (MCP), decay accelerating factor (DAF) and CD 59, on human keratinocytes by supernatant of activated mononuclear cells an d by some individual cytokines present therein. Cultured keratinocytes expr essed MCP, DAF and CD59. Supernatant of activated mononuclear cells and rec ombinant forms of transforming growth factor (TGF)-beta variants (beta 1, b eta 2 and beta 3) up-regulated MCP and CD59 but not DAF. Recombinant IL-1, IL-2, IL-6, TNF-alpha and IFN-gamma had no influence. TGF-beta present in t he supernatant was likely responsible for up-regulation of MCP and CD59. A monoclonal anti-TGF-beta antibody, which neutralized TGF-beta 1, -beta 2 an d -beta 3, did not inhibit the up-regulation of MCP and CD59 by the superna tant. These results indicated that TGF-beta and an additional factor(s) pre sent in the supernatant may be responsible for up-regulating the expression of MCP and CD59 on keratinocytes; both may be acting non-synergistically,