Regulation of complement activity by vaccinia virus complement-control protein

Robin McKenzie, Girish J. Kotwal, Bernard Moss, C. H. Hammer, M. M. Frank

Research output: Contribution to journalArticle


A major protein secreted by vaccinia virus-infected cells has structural similarity to the superfamily of complement-control proteins. This vaccinia complement-control protein (VCP) was studied to determine how it regulates complement activation. VCP was bound by C4b and C3b and served as a cofactor with factor I in cleaving these two molecules. VCP inhibited the formation and accelerated the decay of the classical C3 convertase. It also accelerated decay of the alternative pathway convertase, although higher concentrations were apparently needed. In vitro, therefore, VCP interfered with the classical and alternative complement pathways at several steps. In vivo, this interference may increase the virulence of vaccinia virus by enabling it to escape attack by the host’s complement system.

Original languageEnglish (US)
Pages (from-to)1245-1250
Number of pages6
JournalJournal of Infectious Diseases
Issue number6
Publication statusPublished - 1992
Externally publishedYes


ASJC Scopus subject areas

  • Infectious Diseases
  • Immunology and Allergy
  • Public Health, Environmental and Occupational Health
  • Immunology

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