The first of seven steps in the HIV life cycle. HIV binds to the CD4 receptor and a coreceptor (either CCR5 or CXCR4) on the host cell, causing the viral envelope to fuse with the host cell membrane. This fusion allows HIV to release HIV RNA and HIV enzymes, such as reverse transcriptase and integrase, into the host cell.
See Related Term(s): Fusion Inhibitor, Life Cycle