Complement Component C3 Production and its Cytokine Regulation by Gastrointestinal Epithelial Cells

Abstract

In the gastrointestinal tract, several studies have focused on evidence of local complement activation as one of the factors concerned with the pathogenesis of gastrointestinal disorders. Recently, evidence of local complement component C3 production in intestinal tract were demonstrated in vivo by Ahrenstedt et al., ¹ but its cellular origin has not been identified. In this study, we examined the possibility of C3 production by intestinal epithelial cells using colonic adenocarcinoma cell lines; Caco-2, HT-29, and HT-29N2 cells. The de novo synthesis and secretion of C3 by all three cells were observed, and its production was up-regulated by certain cytokines such as interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)α.