Human immunodeficiency virus-1 induces host genomic R-loops and preferentially integrates its genome near the R-loop...

Area of Science:

• Virology
• Molecular Biology
• Genomics

Background:

• HIV-1 integration typically favors active genes but can occur in non-genic regions.
• Integration into non-genic regions is problematic as these sites are preserved during therapy, contributing to latent infections.
• Understanding HIV-1 integration site selection is crucial for developing effective antiretroviral therapies.

Purpose of the Study:

• To investigate the role of R-loops in HIV-1 integration site selection.
• To determine if R-loops influence HIV-1 integration in both genic and non-genic regions.
• To explore potential therapeutic strategies targeting HIV-1 integration.

Main Methods:

• Utilized VSV-G-pseudotyped HIV-1 for infection studies.
• Employed a HeLa cell model to control transcriptional activity and R-loop formation independently.
• Analyzed HIV-1 integration sites in relation to R-loop formation.
• Investigated physical binding of HIV-1 integrase proteins to R-loops.

Main Results:

• HIV-1 infection induces R-loop formation in both genic and non-genic host genomic regions.
• HIV-1 preferentially integrates into R-loop-rich genomic regions.
• Exogenous R-loop formation directs HIV-1 integration to specific sites.
• HIV-1 integrase proteins were found to physically bind to host genomic R-loops.

Conclusions:

• R-loops are key determinants of HIV-1 integration site selection, irrespective of transcriptional activity.
• HIV-1 integration near R-loops provides a novel mechanistic insight into viral genome insertion.
• These findings open new avenues for developing antiretroviral therapies targeting latent HIV-1 reservoirs.