Retroviruses integrate into the host genome through a process involving reverse transcription and the action of the viral integrase enzyme.

Retroviruses are a specific type of RNA virus that utilize reverse transcriptase to convert their RNA genome into DNA. This newly synthesized DNA is subsequently integrated into the host genome by the viral integrase enzyme. The integration process begins with integrase binding to both the viral DNA and the host DNA. This is followed by 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 significantly impact the host cell. The specific site of integration can influence the expression of adjacent genes, which may lead to altered cellular behavior or even the onset of cancer. Furthermore, the integration of retroviral DNA can result in the formation of proviruses, which are capable of being transmitted to daughter cells during cell division.

Although retroviral integration poses potential risks, certain retroviruses have been repurposed for gene therapy. By modifying the viral genome to eliminate harmful genes and substituting them with therapeutic genes, these retroviruses can effectively deliver beneficial genes to host cells. Nonetheless, it is crucial to carefully evaluate the potential risks associated with retroviral integration when employing these viruses in gene therapy applications.