Hiv Replication Of Cd4 + T Cells And Macrophages Essay

1170 Words 5 Pages
HIV primarily replicates in CD4+ T cells and macrophages. The first step in the HIV replication cycle is entry into target cells. In order to enter cells, the HIV Env trimer interacts with a primary receptor and a co-receptor. CD4 serves as the primary receptor, while C-C motif chemokine receptor type-5 (CCR5) or C-X-C motif chemokine receptor type-4 (CXCR4) can serve as co-receptors.22-24 HIV Env gp120 interacts with the receptor and co-receptor, while HIV gp41 mediates the fusion of viral and cellular membranes. Following membrane fusion, the viral core is released into the cytoplasm of the host cell.
The next step in the HIV replication cycle is uncoating, which is defined as the disassembly of the capsid. While the exact process of uncoating is not completely understood, recent data suggests that the majority of CA is lost shortly after membrane fusion and that the loss of CA is linked to the initiation of reverse transcription.25 Reverse transcription takes place in a large nucleoprotein complex that is derived from the viral core (reverse transcription complex, RTC).26 The virion-associated RT is an RNA-dependent DNA polymerase with RNase H activity and mediates reverse transcription of the ssRNA genome into dsDNA.27,28 As a result of the reverse transcription process, the HIV dsDNA contains 5’ and 3’ long terminal repeats (LTRs) made of the U3-R-U5 regions.29
Reverse transcription triggers the transition of the RTC to the pre-integration complex (PIC), a large…

Related Documents