Project description:Although HIV-1 integration sites are considered to favor active transcription units in the human genome, high-resolution analysis of individual HIV-1 integration sites have shown that the virus can integrate in a variety of host genomic locations, including non-genic regions, challenging the traditional understanding of HIV-1 integration site selection. Here, we showed that HIV-1 targets R-loops, a genomic structure made up of DNA–RNA hybrids, for integration. HIV-1 initiates the formation of R-loops in both genic and non-genic regions of the host genome and preferentially integrates into regions of HIV-1-induced R-loops. Using a cell model that can independently control transcriptional activity and R-loop formation, we demonstrated that the presence of R-loops, regardless of transcriptional activity, directs HIV-1 integration targeting sites. We also found that HIV-1 integrase proteins bind to the host genomic R-loops. These findings provide fundamental insights into the mechanisms of retroviral integration and the new strategies of antiretroviral therapy against HIV-1 latent infection.
Project description:Although HIV-1 integration sites are considered to favor active transcription units in the human genome, high-resolution analysis of individual HIV-1 integration sites have shown that the virus can integrate in a variety of host genomic locations, including non-genic regions, challenging the traditional understanding of HIV-1 integration site selection. Here, we showed that HIV-1 targets R-loops, a genomic structure made up of DNA–RNA hybrids, for integration. HIV-1 initiates the formation of R-loops in both genic and non-genic regions of the host genome and preferentially integrates into regions of HIV-1-induced R-loops. Using a cell model that can independently control transcriptional activity and R-loop formation, we demonstrated that the presence of R-loops, regardless of transcriptional activity, directs HIV-1 integration targeting sites. We also found that HIV-1 integrase proteins bind to the host genomic R-loops. These findings provide fundamental insights into the mechanisms of retroviral integration and the new strategies of antiretroviral therapy against HIV-1 latent infection.
Project description:Although HIV-1 integration sites are considered to favor active transcription units in the human genome, high-resolution analysis of individual HIV-1 integration sites have shown that the virus can integrate in a variety of host genomic locations, including non-genic regions, challenging the traditional understanding of HIV-1 integration site selection. Here, we showed that HIV-1 targets R-loops, a genomic structure made up of DNA–RNA hybrids, for integration. HIV-1 initiates the formation of R-loops in both genic and non-genic regions of the host genome and preferentially integrates into regions of HIV-1-induced R-loops. Using a cell model that can independently control transcriptional activity and R-loop formation, we demonstrated that the presence of R-loops, regardless of transcriptional activity, directs HIV-1 integration targeting sites. We also found that HIV-1 integrase proteins bind to the host genomic R-loops. These findings provide fundamental insights into the mechanisms of retroviral integration and the new strategies of antiretroviral therapy against HIV-1 latent infection.
Project description:Increased morbidity and fetal growth restriction are reported in uninfected children born to human immunodeficiency virus type 1 (HIV-1)–infected women treated with antiretroviral (ARV) therapy. Viruses and/or pharmacological interventions such as ARVs can induce metabolic stress, skewing the cell’s immune response and restricting (cell) growth. Novel metabolomic techniques provided the opportunity to investigate the impact of fetal HIV-1 and combination ARV therapy (cART) exposure on the infants’ immune metabolome. Peroxidized lipids, generated by reactive oxygen species, were increased in cART/HIV-1–exposed infants, indicating altered mitochondrial functioning. The lipid metabolism was further dysregulated with increased triglyceride species and a subsequent decrease in phospholipids in cART/HIV-1–exposed infants compared to control infants. Proinflammatory immune mediators, lysophospholipids as well as cytokines such as CXCL10 and CCL3, were increased whereas anti-inflammatory metabolites from the cytochrome P450 pathway were reduced in cART/HIV-1–exposed infants. Taken together, these data demonstrate that the fetal metabolism is impacted by maternal factors (cART and HIV-1) and skews physiological immune responses toward inflammation in the newborn infant.