How do retroviruses integrate into the host genome?

Retroviruses integrate into the host genome through reverse transcription and integration by the viral integrase enzyme.

Retroviruses are RNA viruses that use reverse transcriptase to convert their RNA genome into DNA. This DNA is then integrated into the host genome by the viral integrase enzyme. The integration process involves the binding of integrase to both the viral DNA and the host DNA, followed by the cleavage of the host DNA and the insertion of the viral DNA into the host genome.

The integration of retroviral DNA into the host genome can have significant effects on the host cell. The integration site can affect the expression of nearby genes, leading to changes in cell behaviour or even the development of cancer. Additionally, the integration of retroviral DNA can lead to the formation of proviruses, which can be passed on to daughter cells during cell division.

Despite the potential risks associated with retroviral integration, some retroviruses have been harnessed for use in gene therapy. By modifying the viral genome to remove harmful genes and replacing them with therapeutic genes, retroviruses can be used to deliver beneficial genes to host cells. However, careful consideration must be given to the potential risks of retroviral integration when using these viruses in gene therapy.