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

The Human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) clade C is a critical viral surface protein responsible for the initial stages of infection (NIH, 2016). It is synthesized as a gp160 precursor and cleaved into two subunits: the surface gp120, which mediates attachment to host CD4 receptors and coreceptors (CCR5 or CXCR4), and the transmembrane gp41, which facilitates the fusion of viral and cellular membranes (NIH, 2011; Wikipedia, 2026). Clade C is the most prevalent HIV-1 subtype globally, accounting for approximately half of all infections, particularly in regions like Sub-Saharan Africa and India (NIH, 2014; MDPI, 2022). As the only viral protein exposed on the virion surface, Env is the primary target for neutralizing antibodies and various entry inhibitors, such as fostemsavir and enfuvirtide (NIH, 2015; PNAS, 2003). Fostemsavir binds to gp120 to prevent CD4 attachment, while enfuvirtide targets gp41 to block membrane fusion (NIH, 2016; PNAS, 2003). Broadly neutralizing antibodies (bNAbs) like VRC01 and CAP256-VRC26.25 are also being developed to target conserved epitopes on the Env trimer (MDPI, 2025). However, its extreme sequence variability and dense glycan shield present significant hurdles for vaccine design and long-term therapeutic efficacy (NIH, 2020). The rapid emergence of escape mutants remains a major challenge in managing HIV-1 infection through Env-targeted therapies (MDPI, 2025).

Other names

HIV-1 Env subtype Cgp160 clade Cgp120/gp41 complex clade CHIV-1 envelope protein clade CHIV-1 envelope glycoprotein (Env) clade C

Inhibition of viral attachment to CD4 receptors, blocking of coreceptor interactions, and prevention of gp41-mediated membrane fusion.