Human immunodeficiency virus type 1 (HIV-1) subtype C antigens (HIV-1 subtype C antigens)

Human immunodeficiency virus type 1 (HIV-1) subtype C antigens are the structural and functional proteins of the most globally dominant HIV-1 clade, accounting for approximately half of all infections worldwide, particularly in Southern Africa and India (Gray et al., 2021, NEJM). These antigens, most notably the envelope glycoprotein (gp120), Gag, and Pol, are the primary components used in vaccine candidates to stimulate "vaccine-elicited immune effectors." These effectors include humoral responses, such as IgG antibodies targeting the V1V2 region of the envelope, and cellular responses, such as polyfunctional CD4+ T-cells (Haynes et al., 2012, NEJM). The biological function of these antigens involves mediating viral entry into host CD4+ T-cells and facilitating viral replication and assembly (NIAID, 2023). In clinical development, these antigens have been tested in large-scale efficacy trials like HVTN 702 (Uhambo), which utilized a canarypox vector (ALVAC-HIV) and a bivalent gp120 protein boost. Despite their critical role as vaccine targets, the high genetic diversity and rapid mutational escape of subtype C antigens remain significant barriers to achieving a protective and durable immune response.

Other names

HIV-1 clade C antigensHIV-1 subtype C envelope proteinsHIV-1 subtype C Gag/Pol/EnvHIV-1 subtype C gp120

Active immunization to elicit humoral and cellular immune responses, including neutralizing antibodies and polyfunctional T-cells, to prevent or control HIV-1 infection.