Impact of mutations in the V2 domain of HIV-1 envelop glycoprotein 120 on the recognition of neutralizing antibodies targeting the CD4-binding site / 中华皮肤科杂志

Objective To investigate the impact of mutations in the V2 domain of HIV-1 envelop glycoprotein (gp) 120 gene on the recognition of neutralizing antibodies (NAbs) specific to the other domains of gp120.MethodsHIV-1 pseudoviruses (JR-FL) containing wild type or V2-mutant gp120 monomers were constructed,and the neutralization of CD4-binding site-specific and CD4-induced NAbs to the HIV-1 pseudoviruses was observed.Enzyme linked immunosorbent assay(ELISA) was performed to evaluate the binding affinity of CD4-binding site-specific and CD4-induced NAbs to wild type or V2-mutant gp120.Results Neither CD4-binding site-specific nor CD4-induced NAbs could neutralize the wild type JR-FL pseudoviruses,but both of them could neutralize pseudoviruses containg the gp120 V2 mutant at a low concentration.There was no significant difference in the binding affinity to CD4-binding site-specific NAbs between the wild type and mutant gp120,while the ELISA binding curves of wild type and mutant gp120 against CD4-induced NAbs were separate,and the affinity of CD4-induced NAbs to the mutant gp120 (L175P) was notably higher than that to the wild type gp120.Conclusion The mutations in the V2 domain of HIV-1 gp120 may affect the antiviral activity of NAbs.

Impact of mutation at V2 of gp120 on V3-specific neutralizing antibodies / 中华微生物学和免疫学杂志

Objective To study the impact of V2 mutations on neutralizing ability of HIV-1-specific neutralizing antibodies. Methods We tested the influence of L175P mutation to the neutralizing ability of V3-specific antibodies by pseudotype virus and the binding affinity of those V3-spesific antibodies to gpl20 monomer by ELISA. Results We found L175P mutation changed the neutralizing ability of V3-specific antibodies. However, L175P mutation showed no effects on the binding affinity of these antibodies to gpl20 monomer. Conclusion Our results revealed the L175P mutation at V2 loop changed the natural trimmer structure of gp120 and enhanced the neutralizing ability of V3-specific antibodies.

Human immunodeficiency virus type 1(HIV-1)V2 L175P mutation increases the binding capability of neutralizing antibodies to HIV-1 / 中华皮肤科杂志

Objective To study the impact of HIV-1 V2 L175P mutation on the binding capability of anti-V3 neutralizing antibodies to HIV-1.Methods A series of eukaryotic cell expression plasmids were used to concatenate wild type and mutant env gene of HIV-1 and green fluorescent protein(GFP)gene.The recombinant plasmids were transfected into 293T cells to express HIV-1 gp120 protein on the surface of cells.The successfully transfected cells were screened by GFP florescence marker.Immunostaining and dual fluorescence flow cytometry were performed to test the binding affinity of several common V3 region specific neutralizing antibodies to wild type or mutant gp120 proteins.Results The mean fluorescence intensity(MFI)of mutant gp120-expressing 293T cells were significantly higher than that of negative control cells(expressing GFP).Flow cytometry showed that the curve for mutant gp120-expressing 293T cells was obviously different in shape and peak from that for the negative control,while most parts of the curve for the wild type gp120-expressing 293T cells overlapped with those for the negative control.Conclusion The V2 region mutation may increase the sensitivity of HIV-1 to the neutralization by V3 region specific antibodies.