Which two HIV envelope glycoproteins are commonly detected in HIV serology as markers?

• A. Gp120 and Gp160
• B. Gp41 and Gp120
• C. Gp24 and Gp55
• D. P24 and Gp120

Answer: (B)

HIV serology centers on detecting antibodies against the virus’s envelope glycoproteins, the proteins that form the surface spikes the virus uses to enter cells. The two main envelope components are gp120, the surface glycoprotein that binds CD4 and co-receptors, and gp41, the transmembrane glycoprotein that completes the fusion process. Because the immune system routinely makes antibodies against these envelope proteins, serology assays are designed to detect anti-gp120 and anti-gp41 antibodies as markers of infection. The alternative gp160 is the precursor that is cleaved to gp120 and gp41, so it isn’t typically counted as a separate envelope marker in standard serology. P24 is a capsid protein, not an envelope protein, and gp55 isn’t a recognized envelope component. Therefore, the two envelope glycoproteins most commonly detected are gp120 and gp41.