Glycoprotein C of herpes simplex virus 1 is an inhibitor of the complement cascade.


Journal Article

Mammalian cells in culture express membrane receptors for C3b when infected with HSV-1. C3b binding is mediated by glycoprotein C (gC), a virus-specified membrane glycoprotein. In view of the inhibitory functions of other C3b-binding proteins, we studied the capacity of gC to modulate complement activation. Glycoprotein C was purified from HSV-1-infected cells by immunoaffinity chromatography. Glycoprotein C, but not a control viral glycoprotein, demonstrated dose-dependent acceleration of decay of C3bBb sites. In addition, gC produced a dose-dependent, time-independent depression of the overall hemolytic efficiency of C3bBb sites. Inhibition of C5b6-initiated reactive lysis of cells bearing C3b, but not cells bearing antibody alone, by gC suggests that the second effect represents interference with the C3b-C5/5b interaction. This hypothesis is supported by the failure of gC to inhibit reactive lysis when added after C5b67 insertion into target cells. Glycoprotein C does not accelerate C14b2a decay, nor does it impair classical pathway hemolytic efficiency when excess C5 is present. By limiting available C5/5b, some gC inhibition of C3b-C5/5b interactions can be unmasked in the classical pathway system. Glycoprotein C is devoid of factor I co-factor activity. HSV-1 gC is a modulator of complement activation, especially via the alternative pathway, and may represent a novel viral mechanism for evading host defense processes.

Full Text

Cited Authors

  • Fries, LF; Friedman, HM; Cohen, GH; Eisenberg, RJ; Hammer, CH; Frank, MM

Published Date

  • September 1, 1986

Published In

Volume / Issue

  • 137 / 5

Start / End Page

  • 1636 - 1641

PubMed ID

  • 3018078

Pubmed Central ID

  • 3018078

International Standard Serial Number (ISSN)

  • 0022-1767


  • eng

Conference Location

  • United States