title: Human immunodeficiency virus type 1 neutralization by a single molecule of V3-targeted antibody.
abstract: Human immunodeficiency virus type-1 (HIV-1) infection generally provokes antibody responses to the viral envelope glycoprotein. Two major regions of gp120, the third variable (V3) domain and the CD4-binding site, have been identified as neutralization targets. The precise mechanism of HIV-1 neutralization by antibodies against the V3 domain is still unknown. It is shown that by kinetic neutralization studies, one molecule of V3-targeted monoclonal antibody (0.5beta) is enough to neutralize one virion. This antibody, which neutralized more than 99% of the virus, inhibited the binding of the virus to cells by 42%. HIV-1 pseudotyped with G glycoprotein from vesicular stomatitis virus was also neutralized by 0.5beta, suggesting that the antibody did not inhibit the viral attachment but caused some alteration in the envelope. These results indicate that the antibody plays an additional role on steric change of the envelope involved in inhibition of viral entry.
authors.affiliation: Department of Medical Virology, Kumamoto University School of Medicine, and Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Kumamoto, Kumamoto 860-0811, Japan. biodef@gpo.kumamoto-u.ac.jp
authors.forename: Shinji
authors.initials: S
authors.lastname: Harada
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology; D000914:Antibodies, Viral / Q000276:immunology*; D015704:CD4 Antigens / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D015699:HIV Envelope Protein gp120 / Q000276:immunology* / Q000378:metabolism; D015497:HIV-1 / Q000276:immunology*; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D009500:Neutralization Tests; D010446:Peptide Fragments / Q000276:immunology* / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D015704:CD4 Antigens; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments