Anti-V3 and anti-IgG antibodies of healthy individuals share complementarity structures

J Acquir Immune Defic Syndr. 1999 Aug 1;21(4):266-70. doi: 10.1097/00126334-199908010-00002.


It was recently shown that antibodies reactive with a peptide from the tip of the HIV-1NY5 gp120 V3 loop (V3 peptide) are present not only in sera of HIV-positive patients but also in sera of healthy HIV-negative individuals. In the present study, we show that V3 peptide reactive antibodies are predominantly IgM in sera of HIV negative individuals and that a fraction of the IgG anti-V3 antibodies exhibit features of autoantibodies. These antibodies were purified by chromatography on IgG-sepharose columns from sera as well as from purified IgG anti-V3 antibodies. A higher IgG anti-V3 reactivity was detected in autoantibody preparations from HIV-positive sera as compared with the reactivity of sera and purified antibodies from HIV-negative individuals. This was confirmed by solid phase binding of IgG anti-V3 antibodies both to V3 and to human IgG F(ab')2 antigens. The autoantibodies did not bind to peptides that share sequence similarity with V3 peptide indicating a high epitope specificity. The detection of antibodies against HIV epitopes in HIV-negative individuals may suggest that anti-V3 antibodies after HIV infection represent at least in part a secondary immune response.

MeSH terms

  • Antibodies, Anti-Idiotypic / blood
  • Antibodies, Anti-Idiotypic / chemistry*
  • Antibody Affinity
  • Autoantibodies / blood
  • Autoantibodies / chemistry
  • Cross Reactions
  • HIV Antibodies / blood
  • HIV Antibodies / chemistry*
  • HIV Envelope Protein gp120 / immunology*
  • HIV Seronegativity / immunology
  • HIV Seropositivity / immunology
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin G / chemistry
  • Immunoglobulin G / immunology*
  • Immunoglobulin M / blood
  • Immunoglobulin M / chemistry
  • Immunoglobulin Variable Region / blood
  • Immunoglobulin Variable Region / chemistry*
  • Peptide Fragments / immunology*


  • Antibodies, Anti-Idiotypic
  • Autoantibodies
  • HIV Antibodies
  • HIV Envelope Protein gp120
  • HIV envelope protein gp120 (305-321)
  • Immunoglobulin G
  • Immunoglobulin M
  • Immunoglobulin Variable Region
  • Peptide Fragments