Reversal of perturbed DNA damage response and HIV latency by histone methyltransferase inhibitor in virally suppressed people living with HIV

Pragati ChavanSathi KoarRohini BingewarAnuja SonawaneJyoti SawantPallavi ShidhayeAmrita RaoRajani BagulUjjwala GhuleSunita KumbharManisha GhateAshwini Shete^*

• ICMR - National Institute of Translational Virology and AIDS Research, Pune, India

Background: Oxidative stress contributes to DNA damage further leading to cellular senescence. HIV infection increases oxidative stress and interferes in DNA damage response. Hence a study was conducted to assess the extent of DNA damage by evaluating global methylation, 8-hydroxy-2′- deoxyguanosine (8-OHdG) and Prelamin A levels in people living with HIV (PLHIV), representing alterations at genetic, epigenetic and structural levels. We also investigated effect of methylation modulators on these markers and HIV latency reversal. Methods: Middle-aged virally suppressed PLHIV on long-term antiretroviral therapy (ART) and noninfected controls were enrolled. Levels of 5-methylcytosine in blood and plasma 8-OHDG were assessed by commercially available colorimetric and ELISA kits, respectively. Reactive oxygen species (ROS) and Prelamin A expression were assessed in T cells by flow cytometry. Levels of DNA damage markers were analysed for correlation with immunosenescent and inflammatory markers. Samples were treated with RG108 and chaetocin to assess their effect on these markers and HIV reactivation. HIV reactivation was assessed by expression of intracellular P24 by flow cytometry and gag copies by Real Time PCR. Results: PLHIV had significantly lower global DNA methylation levels, higher 8-OHdG and Prelamin A levels than their age-matched HIV-uninfected controls. ROS levels did not differ significantly in them. Global methylation and Prelamin A levels correlated with immunesenescent T cells. 8-OHdG levels correlated positively with Angioetensin-2 levels and negatively with proinflammatory cytokines. Treatment with chaetocin increased in global methylation levels and diminished Prelamin A accumulation in CD4+T cells in PLHIV. P24 expressing CD4+T cells increased significantly after Chaetocin treatment indicating HIV latency reversal. Conclusion: PLHIV on ART had higher DNA damage related markers despite of having comparable ROS levels than their age matched controls. Immunotherapeutic potential of chaetocin for reversing premature aging as well as HIV latency needs to be explored further.