Human immunodeficiency virus type 1 Group-specific antigen (HIV-1 Gag) (HIV-1 Gag)

The Human Immunodeficiency Virus type 1 (HIV-1) Group-specific antigen (Gag) is a 55 kDa polyprotein (Pr55Gag) that serves as the primary structural component of the virus [1]. It is essential for the assembly of viral particles, the packaging of the viral RNA genome, and the budding of nascent virions from the host cell membrane [2]. During or shortly after budding, Gag is cleaved by the viral protease into four major domains—matrix (MA), capsid (CA), nucleocapsid (NC), and p6—and two spacer peptides (SP1 and SP2), a process known as maturation that is required for infectivity [3]. Epitopes within the Gag protein, particularly those in the highly conserved capsid region, are major targets for the host's cytotoxic T lymphocyte (CTL) response, making them central to the design of T-cell-based vaccines [5]. Therapeutic interventions targeting Gag include maturation inhibitors like Bevirimat, which block the final cleavage step between CA and SP1, and various vaccine platforms (e.g., mRNA or viral vectors) that present Gag epitopes to the immune system to elicit protective or therapeutic responses [4].

Other names

Pr55GagGag polyproteinGroup-specific antigenHIV-1 Gag epitopesp55

Maturation inhibition by blocking the proteolytic cleavage of the CA-SP1 junction; Induction of cellular immune responses through the presentation of viral epitopes to T-lymphocytes.