scholarly journals Targeted Chromatinization and Repression of HIV-1 Provirus Transcription with Repurposed CRISPR/Cas9

Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1154
Author(s):  
Alex Olson ◽  
Binita Basukala ◽  
Seunghee Lee ◽  
Matthew Gagne ◽  
Wilson W. Wong ◽  
...  
Keyword(s):  
Transcriptional Repression ◽  
Major Barrier ◽  
Guide Rnas ◽  
Immunodeficiency Virus ◽  
Shock And Kill ◽  
Infected Cells ◽  
Latent Hiv ◽  
Transcriptional Repressor Domain ◽  
Hiv 1 ◽  
Latent Provirus

The major barrier to HIV-1 cure is the persistence of latent provirus, which is not eradicated by antiretroviral therapy. The “shock and kill” approach entails stimulating viral production with latency-reversing agents followed by the killing of cells actively producing the virus by immune clearance. However, this approach does not induce all intact proviruses, leaving a residual reservoir. CRISPR/Cas9 has been utilized to excise integrated Human Immunodeficiency Virus (HIV) DNA from infected cells in an RNA-guided, sequence-specific manner. Here, we seek to epigenetically silence the proviral DNA by introducing nuclease-deficient disabled Cas9 (dCas9) coupled with a transcriptional repressor domain derived from Kruppel-associated box (KRAB). We show that specific guide RNAs (gRNAs) and dCas9-KRAB repress HIV-1 transcription and reactivation of latent HIV-1 provirus. This repression is correlated with chromatin changes, including decreased H3 histone acetylation and increased histone H3 lysine 9 trimethylation, histone marks that are associated with transcriptional repression. dCas9-KRAB-mediated inhibition of HIV-1 transcription suggests that CRISPR can be engineered as a tool for block-and-lock strategies.

scholarly journals Efficient inhibition of HIV using CRISPR/Cas13d nuclease system

2021 ◽  
Author(s):  
Hoang Nguyen ◽  
Hannah Wilson ◽  
Sahana Jayakumar ◽  
Viraj Kulkarni ◽  
Smita Kulkarni
Keyword(s):  
T Cells ◽  
Alternative Treatment ◽  
Treatment Modality ◽  
Rna Viruses ◽  
Guide Rnas ◽  
Rna Targeting ◽  
Latently Infected ◽  
Infected Cells ◽  
Latent Hiv ◽  
Hiv 1

Recently discovered Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas13 proteins are programmable RNA-guided ribonucleases that target single-stranded RNA (ssRNA). CRISPR/Cas13 mediated RNA targeting has emerged as a powerful tool for detecting and eliminating RNA viruses. Here, we demonstrate the effectiveness of CRISPR/Cas13d to inhibit HIV-1 replication. We designed guide RNAs (gRNAs) targeting highly conserved regions of HIV-1. RfxCas13d (CasRx) in combination with HIV-specific gRNAs efficiently inhibited HIV-1 replication in cell line models. Furthermore, simultaneous targeting of four distinct sites in the HIV-1 transcript resulted in robust inhibition of HIV-1 replication. We also show the effective HIV-1 inhibition in primary CD4+ T-cells and suppression of HIV-1 reactivated from latently infected cells using the CRISPR/Cas13d system. Our study demonstrates the utility of the CRISPR/Cas13d nuclease system to target acute and latent HIV infection and provides an alternative treatment modality against HIV.

dCas9 targeted chromatin and histone enrichment for mass spectrometry (Catchet-MS) identifies IKZF1 as a novel drug-able target for HIV-1 latency reversal

2021 ◽  
Author(s):  
Enrico Ne ◽  
Raquel Crespo ◽  
Ray Izquierdo-Lara ◽  
Selin Kocer ◽  
Alicja Gorszka ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Transcriptional Repression ◽  
Host Factors ◽  
Hiv Cure ◽  
Polycomb Repressive Complex 2 ◽  
Infected Cells ◽  
Latent Hiv ◽  
Novel Drug ◽  
Enrichment Strategy ◽  
Hiv 1

SummaryA major pharmacological strategy toward HIV cure aims to reverse latency in infected cells as a first step leading to their elimination. While the unbiased identification of molecular targets physically associated with the latent HIV-1 provirus would be highly valuable to unravel the molecular correlates of HIV-1 transcriptional repression and latency reversal, due to technical limitations, this has not been possible. Here we use dCas9 targeted chromatin and histone enrichment strategy coupled to mass spectrometry (Catchet-MS) to isolate the latent and activated HIV-1 5’LTR, followed by MS identification of the differentially locus-bound proteins. Catchet-MS identified known and novel latent 5’LTR-associated host factors. Among these, IKZF1 is a novel HIV-1 transcriptional repressor, required for Polycomb Repressive Complex 2 recruitment to the LTR. We find the drug iberdomide, which targets IKZF1 for degradation, to be a clinically advanced novel LRA that reverses HIV-1 latency in CD4+T-cells isolated from virally suppressed HIV-1 infected participants.

scholarly journals Efficient Inhibition of HIV Using CRISPR/Cas13d Nuclease System

Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1850
Author(s):  
Hoang Nguyen ◽  
Hannah Wilson ◽  
Sahana Jayakumar ◽  
Viraj Kulkarni ◽  
Smita Kulkarni
Keyword(s):  
T Cells ◽  
Alternative Treatment ◽  
Treatment Modality ◽  
Rna Viruses ◽  
Guide Rnas ◽  
Rna Targeting ◽  
Latently Infected ◽  
Infected Cells ◽  
Latent Hiv ◽  
Hiv 1

Recently discovered Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas13 proteins are programmable RNA-guided ribonucleases that target single-stranded RNA (ssRNA). CRISPR/Cas13-mediated RNA targeting has emerged as a powerful tool for detecting and eliminating RNA viruses. Here, we demonstrate the effectiveness of CRISPR/Cas13d to inhibit HIV-1 replication. We designed guide RNAs (gRNAs) targeting highly conserved regions of HIV-1. RfxCas13d (CasRx) in combination with HIV-specific gRNAs efficiently inhibited HIV-1 replication in cell line models. Furthermore, simultaneous targeting of four distinct, non-overlapping sites in the HIV-1 transcript resulted in robust inhibition of HIV-1 replication. We also show the effective HIV-1 inhibition in primary CD4+ T-cells and suppression of HIV-1 reactivated from latently infected cells using the CRISPR/Cas13d system. Our study demonstrates the utility of the CRISPR/Cas13d nuclease system to target acute and latent HIV infection and provides an alternative treatment modality against HIV.

scholarly journals A Critical Review of the Evidence Concerning the HIV Latency Reversing Effect of Disulfiram, the Possible Explanations for Its Inability to Reduce the Size of the Latent Reservoir In Vivo, and the Caveats Associated with Its Use in Practice

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Harry D. J. Knights
Keyword(s):  
Immune Deficiency Syndrome ◽  
Deficiency Syndrome ◽  
Latent Reservoir ◽  
Major Barrier ◽  
Latently Infected ◽  
Shock And Kill ◽  
Infected Cells ◽  
Hiv 1

Combination antiretroviral therapy (cART) effectively suppresses the replication of human immunodeficiency virus type 1 (HIV-1), improves immune function, and decreases the morbidity of acquired immune deficiency syndrome (AIDS). However, it is unable to eradicate the virus because it does not eliminate latently infected cells. The latent reservoir poses the major barrier to an HIV-1 cure. The “shock and kill” strategy aims to reactivate the virus and destroy latently infected cells. Many latency reversing agents (LRAs) reactivate HIV in vitro, but the absence of damaging side-effects and efficacy in vivo make disulfiram particularly promising. However, in clinical trials to date, disulfiram treatment has not resulted in a reduction in the size of the latent reservoir. In this article I will therefore discuss the evidence for the latency reversing effect of disulfiram, the possible explanations for its inability to reduce the size of the latent reservoir in vivo, and the caveats associated with its use in practice. These considerations will help to inform judgements about the prospect of an HIV cure from disulfiram based treatments.

scholarly journals Role of Dendritic Cells in Exposing Latent HIV-1 for the Kill

Viruses ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 37 ◽  
Author(s):  
Jan Kristoff ◽  
Charles R. Rinaldo ◽  
Robbie B. Mailliard
Keyword(s):  
Dendritic Cells ◽  
Ex Vivo ◽  
Latent Reservoir ◽  
Reversal Agents ◽  
Immunodeficiency Virus ◽  
Hiv Eradication ◽  
Infected Cells ◽  
Latent Hiv ◽  
Hiv 1

The development of effective yet nontoxic strategies to target the latent human immunodeficiency virus-1 (HIV-1) reservoir in antiretroviral therapy (ART)-suppressed individuals poses a critical barrier to a functional cure. The ‘kick and kill’ approach to HIV eradication entails proviral reactivation during ART, coupled with generation of cytotoxic T lymphocytes (CTLs) or other immune effectors equipped to eliminate exposed infected cells. Pharmacological latency reversal agents (LRAs) that have produced modest reductions in the latent reservoir ex vivo have not impacted levels of proviral DNA in HIV-infected individuals. An optimal cure strategy incorporates methods that facilitate sufficient antigen exposure on reactivated cells following the induction of proviral gene expression, as well as the elimination of infected targets by either polyfunctional HIV-specific CTLs or other immune-based strategies. Although conventional dendritic cells (DCs) have been used extensively for the purpose of inducing antigen-specific CTL responses in HIV-1 clinical trials, their immunotherapeutic potential as cellular LRAs has been largely ignored. In this review, we discuss the challenges associated with current HIV-1 eradication strategies, as well as the unharnessed potential of ex vivo-programmed DCs for both the ‘kick and kill’ of latent HIV-1.

scholarly journals Nuclear Transit and HIV LTR Binding of NF-κB Subunits Held by IκB Proteins: Implications for HIV-1 Activation

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1162 ◽  
Author(s):  
Sohrab Z. Khan ◽  
Sofia Gasperino ◽  
Steven L. Zeichner
Keyword(s):  
Gene Expression ◽  
Infected Cell ◽  
Knockout Mice ◽  
Gene Expression Regulation ◽  
Strong Increase ◽  
Latently Infected ◽  
Shock And Kill ◽  
Infected Cells ◽  
Latent Hiv ◽  
Hiv 1

No effective therapy to eliminate the HIV latently infected cell reservoir has been developed. One approach, “shock and kill”, employs agents that activate HIV, subsequently killing the activated infected cells and/or virus. Shock and kill requires agents that safely and effectively activate HIV. One class of activation agents works through classical NF-κB pathways, but global NF-κB activators are non-specific and toxic. There exist two major IκBs: IκBα, and IκBε, which hold activating NF-κB subunits in the cytoplasm, releasing them for nuclear transit upon cell stimulation. IκBα was considered the main IκB responsible for gene expression regulation, including HIV activation. IκBε is expressed in cells constituting much of the latent HIV reservoir, and IκBε knockout mice have a minimal phenotype, suggesting that IκBε could be a valuable target for HIV activation and reservoir depletion. We previously showed that targeting IκBε yields substantial increases in HIV expression. Here, we show that IκBε holds c-Rel and p65 activating NF-κB subunits in the cytoplasm, and that targeting IκBε with siRNA produces a strong increase in HIV expression associated with enhanced c-Rel and p65 transit to the nucleus and binding to the HIV LTR of the activating NF-κBs, demonstrating a mechanism through which targeting IκBε increases HIV expression. The findings suggest that it may be helpful to develop HIV activation approaches, acting specifically to target IκBε and its interactions with the NF-κBs.

scholarly journals Potential Utility of Natural Killer Cells for Eliminating Cells Harboring Reactivated Latent HIV-1 Following the Removal of CD8+ T Cell-Mediated Pro-Latency Effect(s)

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1451
Author(s):  
Georges Khoury ◽  
Deanna A. Kulpa ◽  
Matthew S. Parsons
Keyword(s):  
T Cells ◽  
Natural Killer ◽  
Cd8 T Cells ◽  
People Living With Hiv ◽  
Latently Infected ◽  
Shock And Kill ◽  
Infected Cells ◽  
Latent Hiv ◽  
Living With Hiv ◽  
Hiv 1

An impediment to curing HIV-1 infection is the persistence of latently infected cells in ART-treated people living with HIV (PLWH). A key strategy for curing HIV-1 infection is to activate transcription and translation of latent virus using latency reversing agents (LRAs) and eliminate cells harboring reactivated virus via viral cytopathic effect or immune clearance. In this review, we provide an overview of available LRAs and their use in clinical trials. Furthermore, we describe recent data suggesting that CD8+ T cells promote HIV-1 latency in the context of ART, even in the presence of LRAs, which might at least partially explain the clinical inefficiency of previous “shock and kill” trials. Here, we propose a novel cure strategy called “unlock, shock, disarm, and kill”. The general premise of this strategy is to shut down the pro-latency function(s) of CD8+ T cells, use LRAs to reverse HIV-1 latency, counteract anti-apoptotic molecules, and engage natural killer (NK) cells to mediate the killing of cells harboring reactivated latent HIV-1.

scholarly journals Clonal Expansion of Human Immunodeficiency Virus–Infected Cells and Human Immunodeficiency Virus Persistence During Antiretroviral Therapy

2017 ◽  
Vol 215 (suppl_3) ◽  
pp. S119-S127 ◽  
Author(s):  
James I. Mullins ◽  
Lisa M. Frenkel
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiretroviral Therapy ◽  
Viral Replication ◽  
Clonal Expansion ◽  
Homeostatic Proliferation ◽  
Cellular Genes ◽  
Immunodeficiency Virus ◽  
Infected Cells ◽  
Latent Hiv ◽  
Hiv 1

AbstractThe latent HIV-1 reservoir in blood decays very slowly, even during prolonged suppression of viral replication by antiretroviral therapy (ART). Mechanisms for reservoir persistence include replenishment through low-level viral replication, longevity and homeostatic proliferation of memory T cells, and most recently appreciated, clonal expansion of HIV-infected cells. Clonally expanded cells make up a large and increasing fraction of the residual infected cell population on ART, and insertion of HIV proviruses into certain host cellular genes has been associated with this proliferation. That the vast majority of proviruses are defective clouds our assessment of the degree to which clonally expanded cells harbor infectious viruses, and thus the extent to which they contribute to reservoirs relevant to curing infection. This review summarizes past studies that have defined our current understanding and the gaps in our knowledge of the mechanisms by which proviral integration and clonal expansion sustain the HIV reservoir.

DEVELOPMENT OF APPROACHES FOR DETECTION OF GENOME-INTEGRATED PROVIRAL DNA OF THE HUMAN IMMUNODEFICIENCY VIRUS (HIV-1) IN ULTRA LOW CONCENTRATIONS USING THE CRISPR/CAS SYSTEM

2020 ◽  
Author(s):  
M.A. Tyumentseva ◽  
◽  
A.I. Tyumentsev ◽  
V.G. Akimkin ◽  
◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Health Monitoring ◽  
Biological Samples ◽  
Proviral Dna ◽  
Guide Rnas ◽  
Ribonucleoprotein Complexes ◽  
Low Concentrations ◽  
Immunodeficiency Virus ◽  
Hiv 1

For the effective functioning of supervisory and health monitoring services, it is necessary to introduce modern molecular technologies into their practice. Therefore, the task of developing new effective methods for detecting pathogen, for example HIV, based on CRISPR/CAS genome editing systems, remains urgent. In the present work, guide RNAs and specific oligonucleotides were developed for preliminary amplification of highly conserved regions of the HIV-1 genome. The developed guide RNAs make it possible to detect single copies of HIV-1 proviral DNA in vitro as part of CRISPR/CAS ribonucleoprotein complexes in biological samples after preliminary amplification.

scholarly journals Induction of Autophagy to Achieve a Human Immunodeficiency Virus Type 1 Cure

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1798
Author(s):  
Grant R. Campbell ◽  
Stephen A. Spector
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiretroviral Therapy ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Functional Cure ◽  
Immunodeficiency Virus ◽  
Latently Infected ◽  
Infected Cells ◽  
Hiv 1

Effective antiretroviral therapy has led to significant human immunodeficiency virus type 1 (HIV-1) suppression and improvement in immune function. However, the persistence of integrated proviral DNA in latently infected reservoir cells, which drive viral rebound post-interruption of antiretroviral therapy, remains the major roadblock to a cure. Therefore, the targeted elimination or permanent silencing of this latently infected reservoir is a major focus of HIV-1 research. The most studied approach in the development of a cure is the activation of HIV-1 expression to expose latently infected cells for immune clearance while inducing HIV-1 cytotoxicity—the “kick and kill” approach. However, the complex and highly heterogeneous nature of the latent reservoir, combined with the failure of clinical trials to reduce the reservoir size casts doubt on the feasibility of this approach. This concern that total elimination of HIV-1 from the body may not be possible has led to increased emphasis on a “functional cure” where the virus remains but is unable to reactivate which presents the challenge of permanently silencing transcription of HIV-1 for prolonged drug-free remission—a “block and lock” approach. In this review, we discuss the interaction of HIV-1 and autophagy, and the exploitation of autophagy to kill selectively HIV-1 latently infected cells as part of a cure strategy. The cure strategy proposed has the advantage of significantly decreasing the size of the HIV-1 reservoir that can contribute to a functional cure and when optimised has the potential to eradicate completely HIV-1.

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