Fig. 1
From: Epigenetic regulation of HIV-1 latency: focus on polycomb group (PcG) proteins
Cellular and virological events in early HIV-1 infection. HIV-1 infects the cells having CD4 receptor and either of the coreceptor CXCR4 and/or CCR5. The resting cells are less permissive to viral infection due to low metabolism characterized by low level of available dNTPs for energy source and reverse transcription. Various cellular intrinsic factors influence HIV-1 infection process. TRIM5α targets viral capsid and interferes with uncoating process of viral core. Cytidine deaminases, APOBEC3G, or F cause mutation in viral DNA resulting virus inactivation. Tetherin arrests viral particles on the cell membrane and inhibits virion budding. SAMHD1 inhibits viral infection by depleting intracellular pool of dNTPs. Pre-integration latency refers to unintegrated form of HIV-1 genome. In post-integration latency, the integrated form of proviral DNA is silenced by various DNA and chromatin-modifying enzymes