Human complement regulators: a major target for pathogenic microorganisms

Curr Opin Immunol. 2000 Feb;12(1):44-51. doi: 10.1016/s0952-7915(99)00049-7.


The C3 convertases of the human complement system are controlled by fluid-phase and membrane proteins in the RCA (regulators of complement activation) family. Accumulated data show that many pathogenic microorganisms interact with these complement regulators. Recent advances in this field include determination of the crystal structure of the binding domains in the measles virus receptor CD46 and identification of a CD46 transgenic mouse line that is sensitive to measles virus. Moreover, recent findings support the hypothesis that pathogenic bacteria binding fluid-phase RCA proteins exploit these proteins to escape complement attack. These studies provide novel insight into the interplay between pathogens and the innate immune system and may have implications for the plans to use animals expressing an RCA protein for xenotransplantation.

Publication types

  • Review

MeSH terms

  • Antigens, CD / metabolism*
  • CD55 Antigens / metabolism
  • Complement Activation*
  • Complement C3-C5 Convertases / metabolism*
  • Complement C4b-Binding Protein
  • Histocompatibility Antigens / metabolism*
  • Humans
  • Membrane Cofactor Protein
  • Membrane Glycoproteins / metabolism
  • Receptors, Complement 3b / metabolism
  • Receptors, Complement 3d / metabolism
  • Virulence / immunology*


  • Antigens, CD
  • C4BPA protein, human
  • C4BPB protein, human
  • CD46 protein, human
  • CD55 Antigens
  • Complement C4b-Binding Protein
  • Histocompatibility Antigens
  • Membrane Cofactor Protein
  • Membrane Glycoproteins
  • Receptors, Complement 3b
  • Receptors, Complement 3d
  • Complement C3-C5 Convertases