The human umbilical cord vein (HUVEC) endothelial cells synthesize and secrete complement components. We analyzed the regulation of biosynthesis of the third component of complement (C3) and factor B (Bf) by cytokines in endothelial cells. Production of C3 increased after stimulation with TNF-α or IL-1β and that of Bf with TNF-α, TNF-β and IFN-γ. TNF-α was the most effective in stimulating the secretion of C3 and Bf or the expression of mRNA of C3 or Bf. Preincubation with TNF-α for at least 36 or 24 h was needed for the stimulation, respectively. TNF-α, together with IFN-γ had synergistic effects and the release of C3 or Bf increased to about 40- and 26-fold higher than those in control cells after incubation with both cytokines.
- Endothelial cells