THE 3RD COMPONENT OF COMPLEMENT IS TRANSCRIBED AND SECRETED BY CULTURED HUMAN-ENDOTHELIAL CELLS

  • 1 October 1987
    • journal article
    • research article
    • Vol. 129  (1) , 9-13
Abstract
Monotypic cultures of passaged human umbilical vein endothelial cells secrete C3 protein, which is specifically immunoprecipitable from cell lysates and conditioned medium. A transcript migrating at 5.3 kilobases hybridizes with a mouse-derived C3 DNA probe in parallel cultures of endothelial cells, hepatoma cells (HepG2), and freshly isolated human monocytes. Steady-state transcript levels were as follows: HepG2 cells, 1.0; monocytes, 0.05%; endothelial cells, 0.01. These data suggest that C3, an indispensible component for activation of complement by both the classical and alternative pathways, is locally synthesized in the vascular bed.