Abstract 1205 Distinct Residue Patterns in HIV gp120 V3 Loop: Insights into Coreceptor Binding and Infectivity in HIV-1 and HIV-2 Subtypes

Despite sharing a simian genetic origin, HIV-1 and HIV-2 exhibit significant differences in virulence and epidemiology, yet the molecular bases of these disparities remain incompletely understood. Using bioinformatics approaches, we analyzed key differences in the gp120 envelope protein interactions of both viruses, focusing on their high-affinity binding to CD4+ T cells and subsequent coreceptor engagement with CCR5 or CXCR4. HIV-2's comparatively lower infectivity has been partially attributed to its less diverse envelope region, which, despite only 35% amino acid similarity with HIV-1, retains conserved structural elements such as the variable loop 3 (V3).