HIV gp36

HIV gp36 Full Name

Human immunodeficiency virus 2 gp36

HIV gp36 Introduction

HIV-2 gp36 is the transmembrane glycoprotein that pairs with gp125 to form the viral envelope spike complex, structurally and functionally analogous to HIV-1 gp41. As part of the Env complex, gp36–gp125 heterodimers assemble into trimeric spikes on the virion surface, mediating viral fusion and entry into host cells. The transmembrane region of gp36, including membrane-proximal external regions (MPER)-like motifs, is critical for the fusion process, while conserved residues in the C-terminal and adjacent regions contribute to structural stability and proper Env assembly. These features make gp36 a key target for antibodies, with immunogenic epitopes recognized during natural HIV-2 infection or following vaccination. Importantly, gp36's functional similarity to gp41 extends to its six-helix bundle fusion machinery, suggesting that structural motifs in gp36 could be exploited to design vaccines or entry inhibitors that disrupt viral fusion.

Gp36 contains multiple epitopes that elicit humoral responses in HIV-2–infected individuals and vaccinated subjects. Conservation analyses across HIV-2 variants reveal that certain gp36 regions, especially those near the MPER and transmembrane segments, are highly conserved, providing potential targets for broadly reactive antibodies. These conserved motifs support the development of vaccines aiming to elicit neutralizing or binding antibody responses. However, variability in other gp36 regions means that not all antibodies generated against gp36 produce cross-strain neutralization, emphasizing the importance of presenting gp36 in its native trimeric context or in combination with other Env determinants such as gp125 C2/C3/V3 regions. Vaccination strategies, including prime-boost regimens using gp125/gp36 constructs, have shown that gp36-directed antibodies can be elicited, though achieving broadly neutralizing responses may require specific adjuvants and boosting protocols that maintain Env structural integrity.

Beyond vaccine design, gp36 is a robust antigen for serological diagnostics, particularly for distinguishing HIV-2 infections from HIV-1 in regions where both viruses circulate. The gp36 ectodomain is highly immunogenic and commonly included in dual-antigen assays, enabling specific detection of HIV-2 antibodies with high sensitivity and specificity. Cross-reactivity and conserved epitope recognition make gp36 valuable for differential diagnosis, informing treatment and surveillance strategies. Structurally, the transmembrane and MPER-adjacent regions remain promising targets for antibody-based interventions, including neutralizing antibodies or fusion-blocking therapeutics. Overall, gp36's combination of functional importance, structural conservation, and immunogenic potential positions it as a central component for both diagnostic applications and the development of next-generation HIV-2 vaccines and therapeutics, where coordinated targeting with other Env epitopes may enhance efficacy and breadth.

Alternate Names for HIV gp36

Gp36; HIV 2; HIV type 2; Human immunodeficiency virus 2; Human immunodeficiency virus type 2; HIV2 gp36; human immunodeficiency virus 2 gp36

• 1. Jadhav S., et al. Genetic Conservation in gp36 Transmembrane Sequences of Indian HIV Type 2 Isolates. Aids Research and Human Retroviruses. 2011;27(12):1337-1343.
  2. Marcelino J., et al. Potent and Broadly Reactive HIV-2 Neutralizing Antibodies Elicited by a Vaccinia Virus Vector Prime-C2V3C3 Polypeptide Boost Immunization Strategy. Journal of Virology. 2010;84(23):12429-12436.
  3. Shouval D., et al. Enhanced immune response to hepatitis B vaccination through immunization with a Pre-S1/Pre-S2/S Vaccine. Medical Microbiology and Immunology. 2015;204(1):57-68.
  4. 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.