Kirchherr, J. | Search bioRxiv

bioRxiv2026

The ENL-USP7 Complex Regulates HIV Latency Through BRD4 Stabilization

HIV-1 persists in CD4 T cells and brain microglia through host factors that enforce viral latency, yet the mechanisms that stabilize key transcriptional regulators remain incompletely understood. Here, we identify the YEATS domain-containing protein ENL and its associated deubiquitinase USP7 as a host complex that maintains HIV-1 latency. USP7 stabilizes BRD4 by deubiquitination, suppressing HIV transcription and sustaining viral quiescence. Disruption of the ENL-USP7 complex using selective PROTACs reactivates latent HIV in cell line models, as well as in resting CD4 T cells and microglia isolated from people with HIV on antiretroviral therapy. These findings uncover a critical ENL-USP7-BRD4 axis that enforces HIV-1 latency and highlight USP7 as a potential target for latency-reversing strategies. HighlightsO_LIENL, a YEATS domain-containing crotonylation reader, acts as a suppressor rather than an activator of HIV-1 transcription. C_LIO_LIENL recruits USP7 to stabilize BRD4 and enforce viral latency. C_LIO_LIDisruption of the ENL-USP7-BRD4 axis reactivates latent HIV in T cells and microglia. C_LIO_LITargeting USP7 or ENL reveals a therapeutic vulnerability in HIV reservoirs. C_LI

microbiology↗

bioRxiv2023

Aminobisphosphonates reactivate the latent reservoir in people living with HIV-1

Antiretroviral therapy (ART) is not curative due to the existence of cellular reservoirs of latent HIV-1 that persist during therapy. Current research efforts to cure HIV-1 infection include "shock and kill" strategies to disrupt latency using small molecules or latency-reversing agents (LRAs) to induce expression of HIV-1 enabling cytotoxic immune cells to eliminate infected cells. The modest success of current LRAs urges the field to identify novel drugs with increased clinical efficacy. Aminobisphosphonates (N-BPs) that include pamidronate, zoledronate, or alendronate, are the first-line treatment of bone-related diseases including osteoporosis and bone malignancies. Here, we show the use of N-BPs as a novel class of LRA: we found in ex vivo assays using primary cells from ART-suppressed people living with HIV-1 that N-BPs induce HIV-1 from latency to levels that are comparable to the T cell activator phytohemagglutinin (PHA). RNA sequencing and mechanistic data suggested that reactivation may occur through activation of the activator protein 1 signaling pathway. Stored samples from a prior clinical trial aimed at analyzing the effect of alendronate on bone mineral density, provided further evidence of alendronate-mediated latency reversal and activation of immune effector cells. Decay of the reservoir measured by IPDA was however not detected. Our results demonstrate the novel use of N-BPs to reverse HIV-1 latency while inducing immune effector functions. This preliminary evidence merits further investigation in a controlled clinical setting possibly in combination with therapeutic vaccination.

microbiology↗