Human immunodeficiency virus type 1 envelope glycoprotein (HIV-1 Env) trimer (HIV-1 Env)

The HIV-1 envelope glycoprotein (Env) trimer is the primary surface protein of the Human Immunodeficiency Virus type 1 and serves as the sole mediator of viral entry into host cells (Julien et al., 2013). It is a class I fusion protein composed of three gp120-gp41 heterodimers that undergo significant conformational changes upon binding to the host CD4 receptor and co-receptors such as CCR5 or CXCR4. The quaternary apex epitopes, located at the distal end of the trimer and formed by the V1/V2 variable loops, are critical targets for broadly neutralizing antibodies (bNAbs) such as PG9, PG16, and PGT145 (Sok et al., 2014). Isolate C97ZA012 is a specific strain from Clade C, which is the most prevalent HIV-1 subtype globally, making its Env structure a high-priority target for vaccine and therapeutic development (Gorman et al., 2016). Therapeutic strategies targeting these epitopes aim to neutralize the virus by sterically blocking receptor attachment or inhibiting the subsequent fusion process. However, the high degree of glycosylation (the glycan shield) and the rapid mutation rate of the virus present significant challenges for sustained therapeutic efficacy and vaccine design (Wei et al., 2003).

Other names

HIV-1 Env trimergp120/gp41 trimerEnvelope glycoprotein spikeC97ZA012 SOSIPV1/V2 apex epitopes

Neutralization of viral infectivity by binding to the quaternary apex of the Env trimer, thereby sterically hindering CD4 receptor binding or preventing the conformational transitions required for viral-host membrane fusion.