Binding of Human Immunodeficiency Virus Type 1 to the C3b/C4b Receptor CR1 (CD35) and Red Blood Cells in the Presence of Envelope-Specific Antibodies and Complement. National Institutes of Health AIDS Vaccine Clinical Trials Networks

J Infect Dis. 1994 Aug;170(2):429-32. doi: 10.1093/infdis/170.2.429.


Immune complexes formed in vitro by incubating cell-free human immunodeficiency virus type 1 (HIV-1) with sera from infected or gp160-vaccinated persons, together with normal human serum as a source of complement, readily bound to K562 cells expressing recombinant human complement receptor type 1 (CR1). However, antibodies from seronegative persons had little or no effect. This effect was absent in the presence of heat-inactivated or C3-depleted normal human sera or when wild type K562 cells were used, confirming a requirement for complement and CR1. In additional experiments, complement alone targeted HIV-1 to CR1 on red blood cells, and envelope-specific antibodies increased this effect. These results demonstrate that envelope-specific antibodies promote HIV-1 immune complex formation with complement and that these complexes readily bind CR1 on cell surfaces.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antigen-Antibody Complex / metabolism
  • Complement Activation
  • Complement System Proteins / immunology*
  • Erythrocytes / metabolism*
  • Gene Products, env / immunology
  • HIV Antibodies / immunology*
  • HIV Envelope Protein gp160
  • HIV-1 / immunology
  • HIV-1 / metabolism*
  • Humans
  • Immune Sera / immunology
  • Protein Precursors / immunology
  • Receptors, Complement 3b / metabolism*


  • Antigen-Antibody Complex
  • Gene Products, env
  • HIV Antibodies
  • HIV Envelope Protein gp160
  • Immune Sera
  • Protein Precursors
  • Receptors, Complement 3b
  • Complement System Proteins