HIV gp105

HIV gp105 Full Name

Human Immunodeficiency Virus type 2 recombinant glycoprotein gp120

HIV gp105 Introduction

HIV-2 gp105 is the surface subunit (SU) of the envelope glycoprotein complex, forming functional spikes with the transmembrane gp36 (TM) analogous to the HIV-1 gp120/gp41 complex. The gp105/gp36 complex is generated by proteolytic cleavage of a gp160-like precursor via furin-like proteases, a step essential for forming mature trimeric Env spikes competent for receptor binding and membrane fusion. Conservation of the fusion machinery, including the N-terminal fusion peptide and heptad repeat regions, underscores structural constraints that are critical for viral entry and represent potential therapeutic targets. Unlike HIV-1 gp120, gp105 exhibits unique structural features that allow broader receptor interactions, including conventional CD4 binding, engagement with certain coreceptors (e.g., CXCR4, CCR5), and in some isolates, CD4-independent entry via alternative cell-surface molecules. These features provide HIV-2 with a versatile entry strategy, enabling infection of cells with low CD4 expression and influencing tropism across different tissues.

A distinctive feature of gp105 is its ability to bind CD8 molecules on T cells, primarily via the CD8α chain, in addition to canonical CD4 engagement. This CD8 interaction triggers intracellular signaling events, including p56lck phosphorylation and beta-chemokine production, suggesting an immunomodulatory role beyond simple viral attachment. These gp105-mediated signals can influence T cell responses and potentially modulate host immunity, contributing to HIV-2's generally slower disease progression relative to HIV-1. In parallel, gp105 can interact with glycosphingolipids such as GalCer and GM3 on cell membranes, providing alternative attachment pathways that may enhance viral uptake in CD4-low or CD4-negative contexts. Collectively, these receptor and attachment properties highlight gp105 as a multifunctional Env glycoprotein capable of mediating classical entry while simultaneously modulating immune signaling.

Beyond entry, gp105 contributes to the broader immunopathology of HIV-2 infection. Proper Env maturation via furin-like cleavage is essential for functional spike formation, cell-to-cell fusion, and productive infection, while disruptions in cleavage reduce infectivity. gp105 also participates in monocyte-mediated modulation of T cell activation, including suppression of proliferative responses and induction of chemokines, further distinguishing HIV-2 from HIV-1 in host immune interactions. Although some studies describe gp105's role in tetherin antagonism in specific HIV-2/SIV contexts, the generalizable relevance remains under investigation. Overall, gp105 orchestrates a network of receptor engagements—including CD4, CD8, and glycosphingolipid-mediated pathways—coupled with essential maturation processes, positioning it as a central determinant of HIV-2 entry, tropism, and immune modulation, with direct implications for therapeutic targeting and vaccine design.

Alternate Names for HIV gp105

HIV-2 gp105; Human Immunodeficiency Virus Type 2 gp105; gp105; Human immunodeficiency virus; HIV; Human immunodeficiency virus 2; HIV2; HIV-2; Gp105; HIV 2; Human Immunodeficiency Virus Type 2; Retroviridae; Lentivirus; HIV gp105; human immunodeficiency virus gp105

• 1. Planès R., et al. HIV and SIV Envelope Glycoproteins Interact with Glycolipids and Lipids. International Journal of Molecular Sciences. 2023;24(14):11730.
  2. Valadés-Alcaraz A., et al. HIV Transmembrane Glycoprotein Conserved Domains and Genetic Markers Across HIV-1 and HIV-2 Variants. Frontiers in Microbiology. 2022;13.