Figure 1: Fusion of HIV-1 with host cell. The HIV proteins gp120 and gp41, together known as the HIV-1 spike interacts with the receptor CD4 and coreceptor CCR5 or CXCR4. The gp120 sheds off the spike and the gp41 is exposed on the cell surface. Gp41 follows a 6-helix bundle formation and the virus and cell surface fuse and the capsid is released. The inhibitors that are currently approved for therapy that target HIV-1 fusion with cell are indicated in red with maraviroc that targets the co-receptor, CCR5 binding to gp120 and T20 (enfurvitide) that targets gp41 blocking 6-helix bundle formation and therefore fusion of the two membranes. |