Cross-Neutralizing Antibodies in HIV-1 Individuals Infected by Subtypes B, F1, C or the B/Bbr Variant in Relation to the Genetics and Biochemical Characteristics of the env Gene

PLoS One. 2016 Dec 9;11(12):e0167690. doi: 10.1371/journal.pone.0167690. eCollection 2016.

Abstract

Various HIV-1 env genetic and biochemical features impact the elicitation of cross-reactive neutralizing antibodies in natural infections. Thus, we aimed to investigate cross-neutralizing antibodies in individuals infected with HIV-1 env subtypes B, F1, C or the B/Bbr variant as well as env characteristics. Therefore, plasma samples from Brazilian chronically HIV-1 infected individuals were submitted to the TZM-bl neutralization assay. We also analyzed putative N-glycosylation sites (PNGLs) and the size of gp120 variable domains in the context of HIV-1 subtypes prevalent in Brazil. We observed a greater breadth and potency of the anti-Env neutralizing response in individuals infected with the F1 or B HIV-1 subtypes compared with the C subtype and the variant B/Bbr. We observed greater V1 B/Bbr and smaller V4 F1 than those of other subtypes (p<0.005), however neither was there a correlation verified between the variable region length and neutralization potency, nor between PNLG and HIV-1 subtypes. The enrichment of W at top of V3 loop in weak neutralizing response viruses and the P in viruses with higher neutralization susceptibility was statistically significant (p = 0.013). Some other signatures sites were associated to HIV-1 subtype-specific F1 and B/Bbr samples might influence in the distinct neutralizing response. These results indicate that a single amino acid substitution may lead to a distinct conformational exposure or load in the association domain of the trimer of gp120 and interfere with the induction power of the neutralizing response, which affects the sensitivity of the neutralizing antibody and has significant implications for vaccine design.

MeSH terms

  • Antibodies, Neutralizing / immunology*
  • Brazil / epidemiology
  • HIV Antibodies / immunology*
  • HIV Infections / epidemiology
  • HIV Infections / immunology*
  • HIV Infections / virology
  • HIV-1 / genetics*
  • HIV-1 / immunology*
  • Humans
  • Phylogeny
  • env Gene Products, Human Immunodeficiency Virus / genetics*
  • env Gene Products, Human Immunodeficiency Virus / immunology*

Substances

  • Antibodies, Neutralizing
  • HIV Antibodies
  • env Gene Products, Human Immunodeficiency Virus

Grants and funding

This work was supported by the Collaboration for AIDS Vaccine Discovery (CAVD) funded by the Bill & Melinda Gates Foundation (Grant # 38619) Global HIV Vaccine Enterprise (GHVE) Central Service Facilities (CSFs), especially Dr D Montefiori’s Vaccine Immune Monitoring Center (VIMC) (Grant # 383-0920). This work was partially supported by Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro—FAPERJ (grant number E26/110.517/2012). Monick Lindenmeyer Guimarães is recipient of a CNPq Fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.