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.
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.
Montefiori
D C
DC
Dept. of Surgery, Duke University Medical Center, Durham, NC 27710.
Graham
B S
BS
Zhou
J Y
JY
Zhou
J T
JT
Ahearn
J M
JM
D000936:Antigen-Antibody Complex / Q000378:metabolism; D003167:Complement Activation; D003165:Complement System Proteins / Q000276:immunology*; D004912:Erythrocytes / Q000378:metabolism*; D015686:Gene Products, env / Q000276:immunology; D015483:HIV Antibodies / Q000276:immunology*; D019302:HIV Envelope Protein gp160; D015497:HIV-1 / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D011498:Protein Precursors / Q000276:immunology; D017463:Receptors, Complement 3b / Q000378:metabolism*
D000936:Antigen-Antibody Complex; D015686:Gene Products, env; D015483:HIV Antibodies; D019302:HIV Envelope Protein gp160; D007106:Immune Sera; D011498:Protein Precursors; D017463:Receptors, Complement 3b; D003165:Complement System Proteins