CARD8 inflammasome mediates pyroptosis of HIV-1-infected cells by sensing viral protease activity

AbstractHIV-1 has high mutation rates and exists as mutant swarms in the host. Rapid evolution of HIV-1 allows the virus to outpace host immune system, leading to viral persistence. Novel approaches to target immutable components are needed to clear HIV-1 infection. Here we report a pattern-recognition receptor CARD8 that senses enzymatic activity of the HIV-1 protease, which is indispensable for the virus. All subtypes of HIV-1 can be sensed by CARD8 despite substantial viral diversity. HIV-1 evades CARD8 sensing because the viral protease remains inactive in infected cells prior to viral budding. Induction of premature intracellular activation of the viral protease triggers CARD8 inflammasome-mediated pyroptosis of HIV-1-infected cells. This strategy leads to clearance of latent HIV-1 in patient CD4+ T cells after virus reactivation. Taken together, our study identifies CARD8 as an inflammasome sensor of HIV-1 that holds promise as a strategy for clearance of persistent HIV-1 infection.

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CARD8 is an inflammasome sensor for HIV-1 protease activity

Science ◽

10.1126/science.abe1707 ◽

2021 ◽

Vol 371 (6535) ◽

pp. eabe1707 ◽

Cited By ~ 2

Author(s):

Qiankun Wang ◽

Hongbo Gao ◽

Kolin M. Clark ◽

Christian Shema Mugisha ◽

Keanu Davis ◽

...

Keyword(s):

Protease Activity ◽

Rapid Evolution ◽

Viral Persistence ◽

Viral Reactivation ◽

Mutation Rates ◽

Host Immune System ◽

Viral Budding ◽

Infected Cells ◽

Latent Hiv ◽

Hiv 1

HIV-1 has high mutation rates and exists as mutant swarms within the host. Rapid evolution of HIV-1 allows the virus to outpace the host immune system, leading to viral persistence. Approaches to targeting immutable components are needed to clear HIV-1 infection. Here, we report that the caspase recruitment domain–containing protein 8 (CARD8) inflammasome senses HIV-1 protease activity. HIV-1 can evade CARD8 sensing because its protease remains inactive in infected cells before viral budding. Premature intracellular activation of the viral protease triggered CARD8 inflammasome–mediated pyroptosis of HIV-1–infected cells. This strategy led to the clearance of latent HIV-1 in patient CD4+ T cells after viral reactivation. Thus, our study identifies CARD8 as an inflammasome sensor of HIV-1, which holds promise as a strategy for the clearance of persistent HIV-1 infection.

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Mesenchymal stem cells are attracted to latent HIV-1-infected cells and enable virus reactivation via a non-canonical PI3K-NFκB signaling pathway

Scientific Reports ◽

10.1038/s41598-018-32657-y ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 4

Author(s):

Partha K. Chandra ◽

Samantha L. Gerlach ◽

Chengxiang Wu ◽

Namrata Khurana ◽

Lauren T. Swientoniewski ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Signaling Pathway ◽

Virus Reactivation ◽

Infected Cells ◽

Latent Hiv ◽

Hiv 1

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Excision of Latent HIV-1 from Infected Cells In Vivo: An Important Step Forward

Molecular Therapy ◽

10.1016/j.ymthe.2017.04.009 ◽

2017 ◽

Vol 25 (5) ◽

pp. 1062-1064 ◽

Cited By ~ 1

Author(s):

Harshana S. De Silva Feelixge ◽

Keith R. Jerome

Keyword(s):

Infected Cells ◽

Latent Hiv ◽

Hiv 1

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

Oncotarget ◽

10.18632/oncotarget.21585 ◽

2017 ◽

Vol 8 (55) ◽

pp. 94104-94116 ◽

Cited By ~ 5

Author(s):

Hanyu Pan ◽

Panpan Lu ◽

Yinzhong Shen ◽

Yanan Wang ◽

Zhengtao Jiang ◽

...

Keyword(s):

Latently Infected ◽

Infected Cells ◽

Latent Hiv ◽

Hiv 1

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

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00470-21 ◽

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.

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A CRISPR/Cas9 screen identifies the histone demethylase MINA53 as a novel HIV-1 latency-promoting gene (LPG)

Nucleic Acids Research ◽

10.1093/nar/gkz493 ◽

2019 ◽

Vol 47 (14) ◽

pp. 7333-7347 ◽

Cited By ~ 8

Author(s):

Huachao Huang ◽

Weili Kong ◽

Maxime Jean ◽

Guillaume Fiches ◽

Dawei Zhou ◽

...

Keyword(s):

Local Level ◽

Histone Demethylase ◽

Host Factors ◽

Epigenetic Mark ◽

Combination Antiretroviral Therapy ◽

Downstream Effectors ◽

Infected Cells ◽

Latent Hiv ◽

Hiv 1

AbstractAlthough combination antiretroviral therapy is potent to block active replication of HIV-1 in AIDS patients, HIV-1 persists as transcriptionally inactive proviruses in infected cells. These HIV-1 latent reservoirs remain a major obstacle for clearance of HIV-1. Investigation of host factors regulating HIV-1 latency is critical for developing novel antiretroviral reagents to eliminate HIV-1 latent reservoirs. From our recently accomplished CRISPR/Cas9 sgRNA screens, we identified that the histone demethylase, MINA53, is potentially a novel HIV-1 latency-promoting gene (LPG). We next validated MINA53’s function in maintenance of HIV-1 latency by depleting MINA53 using the alternative RNAi approach. We further identified that in vitro MINA53 preferentially demethylates the histone substrate, H3K36me3 and that in cells MINA53 depletion by RNAi also increases the local level of H3K36me3 at LTR. The effort to map the downstream effectors unraveled that H3K36me3 has the cross-talk with another epigenetic mark H4K16ac, mediated by KAT8 that recognizes the methylated H3K36 and acetylated H4K16. Removing the MINA53-mediated latency mechanisms could benefit the reversal of post-integrated latent HIV-1 proviruses for purging of reservoir cells. We further demonstrated that a pan jumonji histone demethylase inhibitor, JIB-04, inhibits MINA53-mediated demethylation of H3K36me3, and JIB-04 synergizes with other latency-reversing agents (LRAs) to reactivate latent HIV-1.

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Potential of the NKG2D/NKG2DL Axis in NK Cell-Mediated Clearance of the HIV-1 Reservoir

International Journal of Molecular Sciences ◽

10.3390/ijms20184490 ◽

2019 ◽

Vol 20 (18) ◽

pp. 4490 ◽

Cited By ~ 2

Author(s):

Maria G. Desimio ◽

Daniela A. Covino ◽

Margherita Doria

Keyword(s):

T Cells ◽

Nk Cells ◽

Nk Cell ◽

Ex Vivo ◽

Virus Reactivation ◽

Major Drawback ◽

Virus Eradication ◽

Latent Hiv ◽

Hiv 1

Viral persistency in latently infected CD4+ T cells despite antiretroviral therapy (ART) represents a major drawback in the fight against HIV-1. Efforts to purge latent HIV-1 have been attempted using latency reversing agents (LRAs) that activate expression of the quiescent virus. However, initial trials have shown that immune responses of ART-treated patients are ineffective at clearing LRA-reactivated HIV-1 reservoirs, suggesting that an adjuvant immunotherapy is needed. Here we overview multiple lines of evidence indicating that natural killer (NK) cells have the potential to induce anti-HIV-1 responses relevant for virus eradication. In particular, we focus on the role of the NKG2D activating receptor that crucially enables NK cell-mediated killing of HIV-1-infected cells. We describe recent data indicating that LRAs can synergize with HIV-1 at upregulating ligands for NKG2D (NKG2DLs), hence sensitizing T cells that exit from viral latency for recognition and lysis by NK cells; in addition, we report in vivo and ex vivo data showing the potential benefits and drawbacks that LRAs may have on NKG2D expression and, more in general, on the cytotoxicity of NK cells. Finally, we discuss how the NKG2D/NKG2DLs axis can be exploited for the development of effective HIV-1 eradication strategies combining LRA-induced virus reactivation with recently optimized NK cell-based immunotherapies.

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Epigenetic compound screening uncovers small molecules for re-activation of latent HIV-1

10.1101/2020.08.21.262311 ◽

2020 ◽

Author(s):

Ariane Zutz ◽

Lin Chen ◽

Franziska Sippl ◽

Christian Schölz

Keyword(s):

High Throughput Screening ◽

Model Systems ◽

Reporter System ◽

Compound Screening ◽

Infected Cells ◽

Low Toxicity ◽

Immunological Destruction ◽

New Treatment ◽

Latent Hiv ◽

Hiv 1

AbstractDuring infection with the human immunodeficiency virus type 1 (HIV-1), latent reservoirs are established, which circumvent full eradication of the virus by antiretroviral therapy (ART) and are the source for viral rebound after cessation of therapy. As these reservoirs are phenotypically undistinguishable from infected cells, current strategies aim to reactivate these reservoirs, followed by pharmaceutical and immunological destruction of the cells.Here, we employed a simple and convenient cell-based reporter system, which enables sample handling under biosafety level (BSL)-1 conditions, to screen for compounds that were able to reactivate latent HIV-1. The assay showed a high dynamic signal range and reproducibility with an average Z-factor of 0.77, classifying the system as robust. The assay was used for high-throughput screening (HTS) of an epigenetic compound library in combination with titration and cell-toxicity studies and revealed several potential new latency reversing agents (LRAs). Further validation in well-known latency model systems verified earlier studies and identified two novel compounds with very high reactivation efficiency and low toxicity. Both drugs, namely N-hydroxy-4-(2-[(2-hydroxyethyl)(phenyl)amino]-2-oxoethyl)benzamide (HPOB) and 2',3'-difluoro-[1,1'-biphenyl]-4-carboxylic acid, 2-butylhydrazide (SR-4370), showed comparable performances to other already known LRAs, did not activate CD4+ T-cells or caused changes in the composition of PBMCs as shown by flow cytometry analyses.Both compounds may represent an effective new treatment possibility for revocation of latency in HIV-1 infected individuals.

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