Neutralizing antibodies decrease the envelope fluidity of HIV-1.
For successful penetration of HIV-1, the formation of a fusion pore may be required in order to accumulate critical numbers of fusion-activated gp41 with the help of fluidization of the plasma membrane and viral envelope. An increase in temperature to 40 degrees C after viral adsorption at 25 degrees C enhanced the infectivity by 1.4-fold. The enhanced infectivity was inhibited by an anti-CXCR4 peptide, T140, and anti-V3 monoclonal antibodies (0.5beta and 694/98-D) by post-attachment neutralization, but not by non-neutralizing antibodies (670-30D and 246-D) specific for the C5 of gp120 and cluster I of gp41, respectively. Anti-HLA-II and an anti-HTLV-I gp46 antibody, LAT27, neutralized the molecule-carrying HIV-1(C-2(MT-2)). The anti-V3 antibodies suppressed the fluidity of the HIV-1(C-2) envelope, whereas the non-neutralizing antibodies did not. The anti-HLA-II antibody decreased the envelope fluidity of HIV-1(C-2(MT-2)), but not that of HIV-1(C-2). Therefore, fluidity suppression by these antibodies represents an important neutralization mechanism, in addition to inhibition of viral attachment.
Harada
Shinji
S
Department of Medical Virology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto 860-8556, Japan. biodef@gpo.kumamoto-u.ac.jp
Monde
Kazuaki
K
Tanaka
Yuetsu
Y
Kimura
Tetsuya
T
Maeda
Yosuke
Y
Yusa
Keisuke
K
D000911:Antibodies, Monoclonal / Q000276:immunology*; D002460:Cell Line; D002462:Cell Membrane / Q000821:virology; D015483:HIV Antibodies / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology; D015497:HIV-1 / Q000276:immunology / Q000472:pathogenicity*; D006367:HeLa Cells; D006801:Humans; D008560:Membrane Fluidity / Q000502:physiology*; D008561:Membrane Fusion; D009500:Neutralization Tests; D010446:Peptide Fragments / Q000276:immunology
D000911:Antibodies, Monoclonal; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments