HIV-1 envelope glycoprotein gp120, V2 apex region (V2 apex)

The V2 apex region of the HIV-1 envelope glycoprotein gp120 is a critical structural domain located at the top of the trimeric Env spike (Ward & Wilson, 2017; NIH.gov). It plays a central role in the virus's ability to infect host cells by stabilizing the prefusion state of the trimer and shielding vulnerable sites, such as the CD4-binding site and the V3 loop, from the immune system (Pancera et al., 2013; PubMed). This region is characterized by high sequence variability and extensive N-linked glycosylation, particularly the conserved N160 glycan, which forms a key part of the epitope for many broadly neutralizing antibodies (bNAbs) (Walker et al., 2009; NIH.gov). Therapeutic strategies targeting the V2 apex focus on the use of bNAbs, such as PG9 and PGT145, to block viral entry by preventing the conformational changes required for fusion (McLellan et al., 2011; ResearchGate). Additionally, the V2 apex is a primary focus for vaccine development, as antibodies targeting this region were identified as a correlate of protection in the RV144 clinical trial (Rolland et al., 2012; Nature). However, the extreme diversity of the V2 region and the virus's ability to rapidly evolve escape mutations through glycan shifting or sequence changes present significant challenges for therapeutic and prophylactic interventions (Doria-Rose et al., 2014; NIH.gov).

Other names

V1V2 domain apexV2-glycan epitopeV2 loop apexgp120 V2 regionQuaternary V1V2 epitope

Neutralization of HIV-1 by binding to the quaternary apex of the envelope trimer, thereby blocking CD4 receptor engagement or preventing the conformational transitions necessary for viral-host membrane fusion.