scholarly journals Long Noncoding RNA uc002yug.2 Activates HIV-1 Latency through Regulation of mRNA Levels of Various RUNX1 Isoforms and Increased Tat Expression

2018 ◽  
Vol 92 (9) ◽  
Author(s):  
Chen Huan ◽  
Zhaolong Li ◽  
Shanshan Ning ◽  
Hong Wang ◽  
Xiao-Fang Yu ◽  
...  
Keyword(s):  
Noncoding Rna ◽  
Therapeutic Interventions ◽  
Viral Reservoir ◽  
Mrna Levels ◽  
Tat Protein ◽  
Latent Viral Reservoir ◽  
Latently Infected ◽  
Primary Obstacle ◽  
Latent Hiv ◽  
Hiv 1

ABSTRACT The HIV-1 reservoir is a major obstacle to complete eradication of the virus. Although many proteins and RNAs have been characterized as regulators in HIV-1/AIDS pathogenesis and latency, only a few long noncoding RNAs (lncRNAs) have been shown to be closely associated with HIV-1 replication and latency. In this study, we demonstrated that lncRNA uc002yug.2 plays a key role in HIV-1 replication and latency. uc002yug.2 potentially enhances HIV-1 replication, long terminal repeat (LTR) activity, and the activation of latent HIV-1 in both cell lines and CD4 + T cells from patients. Further investigation revealed that uc002yug.2 activates latent HIV-1 through downregulating RUNX1b and -1c and upregulating Tat protein expression. The accumulated evidence supports our model that the Tat protein has the key role in the uc002yug.2-mediated regulatory effect on HIV-1 reactivation. Moreover, uc002yug.2 showed an ability to activate HIV-1 similar to that of suberoylanilide hydroxamic acid or phorbol 12-myristate 13-acetate using latently infected cell models. These findings improve our understanding of lncRNA regulation of HIV-1 replication and latency, providing new insights into potential targeted therapeutic interventions. IMPORTANCE The latent viral reservoir is the primary obstacle to curing HIV-1 disease. To date, only a few lncRNAs, which play major roles in various biological processes, including viral infection, have been identified as regulators in HIV-1 latency. In this study, we demonstrated that lncRNA uc002yug.2 is important for both HIV-1 replication and activation of latent viruses. Moreover, uc002yug.2 was shown to activate latent HIV-1 through regulating alternative splicing of RUNX1 and increasing the expression of Tat protein. These findings highlight the potential merit of targeting lncRNA uc002yug.2 as an activating agent for latent HIV-1.

A new small-molecule compound, Q308, silences latent HIV-1 provirus by suppressing Tat- and FACT-mediated transcription

2021 ◽  
Author(s):  
Chen-liang Zhou ◽  
Yi-fan Huang ◽  
Yi-bin Li ◽  
Tai-zhen Liang ◽  
Teng-yi Zheng ◽  
...  
Keyword(s):  
Small Molecule ◽  
Difficult Problem ◽  
Viral Reservoir ◽  
Functional Cure ◽  
Latently Infected ◽  
Small Molecule Compound ◽  
Infected Cells ◽  
Latent Hiv ◽  
Anti Hiv ◽  
Hiv 1

Eliminating the latent HIV reservoir remains a difficult problem for creating an HIV functional cure or achieving remission. The “block-and-lock” strategy aims to steadily suppress transcription of the viral reservoir and lock the HIV promoter in deep latency using latency-promoting agents (LPAs). However, to date, most of the investigated LPA candidates are not available for clinical trials, and some of them exhibit immune-related adverse reactions. The discovery and development of new, active, and safe LPA candidates for an HIV cure are necessary to eliminate residual HIV-1 viremia through the “block-and-lock” strategy. In this study, we demonstrated that a new small-molecule compound, Q308, silenced the HIV-1 provirus by inhibiting Tat-mediated gene transcription and selectively downregulating the expression levels of the facilitated chromatin transcription (FACT) complex. Strikingly, Q308 induced the preferential apoptosis in HIV-1 latently infected cells, indicating that Q308 may reduce the size of the viral reservoir and thus further prevent viral rebound. These findings highlight that Q308 is a novel and safe anti-HIV-1 inhibitor candidate for a functional cure.

scholarly journals A New Quinoline BRD4 Inhibitor Targets a Distinct Latent HIV-1 Reservoir for Reactivation from Other “Shock” Drugs

2018 ◽  
Vol 92 (10) ◽  
Author(s):  
Erik Abner ◽  
Mateusz Stoszko ◽  
Lei Zeng ◽  
Heng-Chang Chen ◽  
Andrea Izquierdo-Bouldstridge ◽  
...  
Keyword(s):  
Hdac Inhibitors ◽  
Jurkat Cells ◽  
Viral Reactivation ◽  
Viral Reservoir ◽  
Latently Infected ◽  
Core Histones ◽  
Latent Hiv ◽  
Expression Microarrays ◽  
Hiv 1

ABSTRACT Upon HIV-1 infection, a reservoir of latently infected resting T cells prevents the eradication of the virus from patients. To achieve complete depletion, the existing virus-suppressing antiretroviral therapy must be combined with drugs that reactivate the dormant viruses. We previously described a novel chemical scaffold compound, MMQO (8-methoxy-6-methylquinolin-4-ol), that is able to reactivate viral transcription in several models of HIV latency, including J-Lat cells, through an unknown mechanism. MMQO potentiates the activity of known latency-reversing agents (LRAs) or “shock” drugs, such as protein kinase C (PKC) agonists or histone deacetylase (HDAC) inhibitors. Here, we demonstrate that MMQO activates HIV-1 independently of the Tat transactivator. Gene expression microarrays in Jurkat cells indicated that MMQO treatment results in robust immunosuppression, diminishes expression of c-Myc, and causes the dysregulation of acetylation-sensitive genes. These hallmarks indicated that MMQO mimics acetylated lysines of core histones and might function as a bromodomain and extraterminal domain protein family inhibitor (BETi). MMQO functionally mimics the effects of JQ1, a well-known BETi. We confirmed that MMQO interacts with the BET family protein BRD4. Utilizing MMQO and JQ1, we demonstrate how the inhibition of BRD4 targets a subset of latently integrated barcoded proviruses distinct from those targeted by HDAC inhibitors or PKC pathway agonists. Thus, the quinoline-based compound MMQO represents a new class of BET bromodomain inhibitors that, due to its minimalistic structure, holds promise for further optimization for increased affinity and specificity for distinct bromodomain family members and could potentially be of use against a variety of diseases, including HIV infection. IMPORTANCE The suggested “shock and kill” therapy aims to eradicate the latent functional proportion of HIV-1 proviruses in a patient. However, to this day, clinical studies investigating the “shocking” element of this strategy have proven it to be considerably more difficult than anticipated. While the proportion of intracellular viral RNA production and general plasma viral load have been shown to increase upon a shock regimen, the global viral reservoir remains unaffected, highlighting both the inefficiency of the treatments used and the gap in our understanding of viral reactivation in vivo . Utilizing a new BRD4 inhibitor and barcoded HIV-1 minigenomes, we demonstrate that PKC pathway activators and HDAC and bromodomain inhibitors all target different subsets of proviral integration. Considering the fundamental differences of these compounds and the synergies displayed between them, we propose that the field should concentrate on investigating the development of combinatory shock cocktail therapies for improved reservoir reactivation.

scholarly journals Epigenetic Mechanisms of HIV-1 Persistence

Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 514
Author(s):  
Roxane Verdikt ◽  
Olivier Hernalsteens ◽  
Carine Van Lint
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Rational Design ◽  
Therapeutic Interventions ◽  
Regulatory Mechanisms ◽  
Viral Reservoir ◽  
Epigenetic Mechanisms ◽  
Latently Infected ◽  
Hiv 1

Eradicating HIV-1 in infected individuals will not be possible without addressing the persistence of the virus in its multiple reservoirs. In this context, the molecular characterization of HIV-1 persistence is key for the development of rationalized therapeutic interventions. HIV-1 gene expression relies on the redundant and cooperative recruitment of cellular epigenetic machineries to cis-regulatory proviral regions. Furthermore, the complex repertoire of HIV-1 repression mechanisms varies depending on the nature of the viral reservoir, although, so far, few studies have addressed the specific regulatory mechanisms of HIV-1 persistence in other reservoirs than the well-studied latently infected CD4+ T cells. Here, we present an exhaustive and updated picture of the heterochromatinization of the HIV-1 promoter in its different reservoirs. We highlight the complexity, heterogeneity and dynamics of the epigenetic mechanisms of HIV-1 persistence, while discussing the importance of further understanding HIV-1 gene regulation for the rational design of novel HIV-1 cure strategies.

scholarly journals The bromodomain and extraterminal domain inhibitor bromosporine synergistically reactivates latent HIV-1 in latently infected cells

Oncotarget ◽  
2017 ◽  
Vol 8 (55) ◽  
pp. 94104-94116 ◽  
Author(s):  
Hanyu Pan ◽  
Panpan Lu ◽  
Yinzhong Shen ◽  
Yanan Wang ◽  
Zhengtao Jiang ◽  
...  
Keyword(s):  
Latently Infected ◽  
Infected Cells ◽  
Latent Hiv ◽  
Hiv 1

scholarly journals 19 Quantification and correlates of the replication competent HIV-1 latent viral reservoir in a virally suppressed Ugandan population

2016 ◽  
Vol 2 ◽  
pp. 15
Author(s):  
J.L. Prodger ◽  
J.D. Siliciano ◽  
J. Lai ◽  
S.J. Reynolds ◽  
J. Kasule ◽  
...  
Keyword(s):  
Viral Reservoir ◽  
Latent Viral Reservoir ◽  
Hiv 1 ◽  
Ugandan Population

scholarly journals 8 IFNα activates latent HIV-1 in non-proliferating latently infected T-cells

2016 ◽  
Vol 2 ◽  
pp. 10-11
Author(s):  
R.M. Sluis ◽  
N.A. Kumar ◽  
V.A. Evans ◽  
A.N. Harman ◽  
T. Mota ◽  
...  
Keyword(s):  
T Cells ◽  
Latently Infected ◽  
Latent Hiv ◽  
Hiv 1

scholarly journals SAMHD1 Impairs HIV-1 Gene Expression and Negatively Modulates Reactivation of Viral Latency in CD4+ T Cells

2018 ◽  
Vol 92 (15) ◽  
Author(s):  
Jenna M. Antonucci ◽  
Sun Hee Kim ◽  
Corine St. Gelais ◽  
Serena Bonifati ◽  
Tai-Wei Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Leukemia Virus ◽  
Viral Latency ◽  
Viral Reservoir ◽  
Latently Infected ◽  
Ltr Promoter ◽  
Hiv 1

ABSTRACT Sterile alpha motif and HD domain-containing protein 1 (SAMHD1) restricts human immunodeficiency virus type 1 (HIV-1) replication in nondividing cells by degrading intracellular deoxynucleoside triphosphates (dNTPs). SAMHD1 is highly expressed in resting CD4+ T cells, which are important for the HIV-1 reservoir and viral latency; however, whether SAMHD1 affects HIV-1 latency is unknown. Recombinant SAMHD1 binds HIV-1 DNA or RNA fragments in vitro, but the function of this binding remains unclear. Here we investigate the effect of SAMHD1 on HIV-1 gene expression and reactivation of viral latency. We found that endogenous SAMHD1 impaired HIV-1 long terminal repeat (LTR) activity in monocytic THP-1 cells and HIV-1 reactivation in latently infected primary CD4+ T cells. Overexpression of wild-type (WT) SAMHD1 suppressed HIV-1 LTR-driven gene expression at a transcriptional level. Tat coexpression abrogated SAMHD1-mediated suppression of HIV-1 LTR-driven luciferase expression. SAMHD1 overexpression also suppressed the LTR activity of human T-cell leukemia virus type 1 (HTLV-1), but not that of murine leukemia virus (MLV), suggesting specific suppression of retroviral LTR-driven gene expression. WT SAMHD1 bound to proviral DNA and impaired reactivation of HIV-1 gene expression in latently infected J-Lat cells. In contrast, a nonphosphorylated mutant (T592A) and a dNTP triphosphohydrolase (dNTPase) inactive mutant (H206D R207N [HD/RN]) of SAMHD1 failed to efficiently suppress HIV-1 LTR-driven gene expression and reactivation of latent virus. Purified recombinant WT SAMHD1, but not the T592A and HD/RN mutants, bound to fragments of the HIV-1 LTR in vitro. These findings suggest that SAMHD1-mediated suppression of HIV-1 LTR-driven gene expression potentially regulates viral latency in CD4+ T cells. IMPORTANCE A critical barrier to developing a cure for HIV-1 infection is the long-lived viral reservoir that exists in resting CD4+ T cells, the main targets of HIV-1. The viral reservoir is maintained through a variety of mechanisms, including regulation of the HIV-1 LTR promoter. The host protein SAMHD1 restricts HIV-1 replication in nondividing cells, but its role in HIV-1 latency remains unknown. Here we report a new function of SAMHD1 in regulating HIV-1 latency. We found that SAMHD1 suppressed HIV-1 LTR promoter-driven gene expression and reactivation of viral latency in cell lines and primary CD4+ T cells. Furthermore, SAMHD1 bound to the HIV-1 LTR in vitro and in a latently infected CD4+ T-cell line, suggesting that the binding may negatively modulate reactivation of HIV-1 latency. Our findings indicate a novel role for SAMHD1 in regulating HIV-1 latency, which enhances our understanding of the mechanisms regulating proviral gene expression in CD4+ T cells.

scholarly journals HIV-1 Vpr mediates the depletion of the cellular repressor CTIP2 to counteract viral gene silencing

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
F. Forouzanfar ◽  
S. Ali ◽  
C. Wallet ◽  
M. De Rovere ◽  
C. Ducloy ◽  
...  
Keyword(s):  
Gene Silencing ◽  
Viral Gene ◽  
Target Cells ◽  
Viral Reservoirs ◽  
Ubiquitin Ligase Complex ◽  
Latently Infected ◽  
Cellular Cofactor ◽  
Proteasome Pathway ◽  
Latent Hiv ◽  
Hiv 1

Abstract Mammals have evolved many antiviral factors impacting different steps of the viral life cycle. Associated with chromatin-modifying enzymes, the cellular cofactor CTIP2 contributes to HIV-1 gene silencing in latently infected reservoirs that constitute the major block toward an HIV cure. We report, for the first time, that the virus has developed a strategy to overcome this major transcriptional block. Productive HIV-1 infection results in a Vpr-mediated depletion of CTIP2 in microglial cells and CD4+ T cells, two of the major viral reservoirs. Associated to the Cul4A-DDB1-DCAF1 ubiquitin ligase complex, Vpr promotes CTIP2 degradation via the proteasome pathway in the nuclei of target cells and notably at the latent HIV-1 promoter. Importantly, Vpr targets CTIP2 associated with heterochromatin-promoting enzymes dedicated to HIV-1 gene silencing. Thereby, Vpr reactivates HIV-1 expression in a microglial model of HIV-1 latency. Altogether our results suggest that HIV-1 Vpr mediates the depletion of the cellular repressor CTIP2 to counteract viral gene silencing.

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