scholarly journals CARD8 inflammasome sensitization through DPP9 inhibition enhances NNRTI-triggered killing of HIV-1-infected cells

2021 ◽  
Author(s):  
Kolin M Clark ◽  
Qiankun Wang ◽  
Liang Shan
Keyword(s):  
Negative Regulator ◽  
Reverse Transcriptase Inhibitors ◽  
Viral Protease ◽  
Nnrti Resistance ◽  
Promising Strategy ◽  
Protease Activation ◽  
Infected Cells ◽  
Chemical Inhibition ◽  
High Concentrations ◽  
Hiv 1

Non-nucleoside reverse transcriptase inhibitors (NNRTIs) induce pyroptosis of HIV-1 infected CD4+ T cells through induction of intracellular viral protease activation, which then activates the CARD8 inflammasome. Due to high concentrations of NNRTIs being required for efficient CARD8 activation and elimination of HIV-1-infected cells, it is important to elucidate ways to sensitize the CARD8 inflammasome to NNRTI-induced activation. We show that this sensitization can be done through chemical inhibition of the CARD8 negative regulator DPP9. DPP9 inhibitor Val-boroPro (VbP) can act synergistically with NNRTIs to increase their efficacy in killing HIV-1-infected cells. We also show that VbP is able to partially overcome issues with NNRTI resistance and is capable of killing infected cells without the presence of NNRTIs. This offers a promising strategy for enhancing NNRTI efficacy in elimination of HIV-1 reservoirs in patients.

scholarly journals Characterization and Structural Analysis of Novel Mutations in Human Immunodeficiency Virus Type 1 Reverse Transcriptase Involved in the Regulation of Resistance to Nonnucleoside Inhibitors

2007 ◽  
Vol 81 (20) ◽  
pp. 11507-11519 ◽  
Author(s):  
Francesca Ceccherini-Silberstein ◽  
Valentina Svicher ◽  
Tobias Sing ◽  
Anna Artese ◽  
Maria Mercedes Santoro ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Reverse Transcriptase Inhibitors ◽  
Data Set ◽  
Nnrti Resistance ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Resistance to antivirals is a complex and dynamic phenomenon that involves more mutations than are currently known. Here, we characterize 10 additional mutations (L74V, K101Q, I135M/T, V179I, H221Y, K223E/Q, and L228H/R) in human immunodeficiency virus type 1 (HIV-1) reverse transcriptase which are involved in the regulation of resistance to nonnucleoside reverse transcriptase inhibitors (NNRTIs). These mutations are strongly associated with NNRTI failure and strongly correlate with the classical NNRTI resistance mutations in a data set of 1,904 HIV-1 B-subtype pol sequences from 758 drug-naïve patients, 592 nucleoside reverse transcriptase inhibitor (NRTI)-treated but NNRTI-naïve patients, and 554 patients treated with both NRTIs and NNRTIs. In particular, L74V and H221Y, positively correlated with Y181C, were associated with an increase in Y181C-mediated resistance to nevirapine, while I135M/T mutations, positively correlated with K103N, were associated with an increase in K103N-mediated resistance to efavirenz. In addition, the presence of the I135T polymorphism in NNRTI-naïve patients significantly correlated with the appearance of K103N in cases of NNRTI failure, suggesting that I135T may represent a crucial determinant of NNRTI resistance evolution. Molecular dynamics simulations show that I135T can contribute to the stabilization of the K103N-induced closure of the NNRTI binding pocket by reducing the distance and increasing the number of hydrogen bonds between 103N and 188Y. H221Y also showed negative correlations with type 2 thymidine analogue mutations (TAM2s); its copresence with the TAM2s was associated with a higher level of zidovudine susceptibility. Our study reinforces the complexity of NNRTI resistance and the significant interplay between NRTI- and NNRTI-selected mutations. Mutations beyond those currently known to confer resistance should be considered for a better prediction of clinical response to reverse transcriptase inhibitors and for the development of more efficient new-generation NNRTIs.

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

2020 ◽  
Author(s):  
Qiankun Wang ◽  
Hongbo Gao ◽  
Kolin M. Clark ◽  
Pengfei Tang ◽  
Gray H. Harlan ◽  
...  
Keyword(s):  
Rapid Evolution ◽  
Mutation Rates ◽  
Host Immune System ◽  
Virus Reactivation ◽  
Viral Protease ◽  
Viral Budding ◽  
Infected Cells ◽  
Latent Hiv ◽  
Hiv 1 ◽  
Recognition Receptor

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.

scholarly journals Retroviral cDNA Integration: Stimulation by HMG I Family Proteins

2000 ◽  
Vol 74 (23) ◽  
pp. 10965-10974 ◽  
Author(s):  
Ling Li ◽  
Kristine Yoder ◽  
Mark S. T. Hansen ◽  
Jennifer Olvera ◽  
Michael D. Miller ◽  
...  
Keyword(s):  
Dna Binding ◽  
Leukemia Virus ◽  
Moloney Murine Leukemia Virus ◽  
Dna Binding Domains ◽  
Binding Domains ◽  
Infected Cells ◽  
High Concentrations ◽  
Cdna Integration ◽  
Hiv 1

ABSTRACT To replicate, a retrovirus must synthesize a cDNA copy of the viral RNA genome and integrate that cDNA into a chromosome of the host. We have investigated the role of a host cell cofactor, HMG I(Y) protein, in integration of human immunodeficiency virus type 1 (HIV-1) and Moloney murine leukemia virus (MoMLV) cDNA. Previously we reported that HMG I(Y) cofractionates with HIV-1 preintegration complexes (PICs) isolated from freshly infected cells. PICs depleted of required components by treatment with high concentrations of salt could be reconstituted by addition of purified HMG I(Y) in vitro. Here we report studies using immunoprecipitation that indicate that HMG I(Y) is associated with MoMLV preintegration complexes. In mechanistic studies, we show for both HIV-1 and MoMLV that each HMG I(Y) monomer must contain multiple DNA binding domains to stimulate integration by HMG I(Y)-depleted PICs. We also find that HMG I(Y) can condense model HIV-1 or MoMLV cDNA in vitro as measured by stimulation of intermolecular ligation. This reaction, like reconstitution of integration, depends on the presence of multiple DNA binding domains in each HMG I(Y) monomer. These data suggest that binding of multivalent HMG I(Y) monomers to multiple cDNA sites compacts retroviral cDNA, thereby promoting formation of active integrase-cDNA complexes.

scholarly journals Toxins that are activated by HIV type-1 protease through removal of a signal for degradation by the N-end-rule pathway

1999 ◽  
Vol 343 (1) ◽  
pp. 199-207 ◽  
Author(s):  
Pål Ø. FALNES ◽  
Reinhold WELKER ◽  
Hans-Georg KRÄUSSLICH ◽  
Sjur OLSNES
Keyword(s):  
Protein Synthesis ◽  
Diphtheria Toxin ◽  
Mammalian Cells ◽  
Cellular Protein ◽  
Viral Protease ◽  
Infected Cells ◽  
Hiv Type 1 ◽  
Hiv 1 ◽  
Cellular Protein Synthesis

Diphtheria toxin enters the cytosol of mammalian cells where it inhibits cellular protein synthesis, leading to cell death. Recently we found that the addition of a signal for N-end-rule-mediated protein degradation to diphtheria toxin substantially reduced its intracellular stability and toxicity. These results prompted us to construct a toxin containing a degradation signal that is removable through the action of a viral protease. In principle, such a toxin would be preferentially stabilized, and thus activated, in cells expressing the viral protease in the cytosol, i.e. virus-infected cells, thereby providing a specific eradication of these cells. In the present work we describe the construction of toxins that contain a signal for N-end-rule-mediated degradation just upstream of a cleavage site for the protease from HIV type 1 (HIV-1 PR). We show that the toxins are cleaved by HIV-1 PR exclusively at the introduced sites, and thereby are converted from unstable to stable proteins. Furthermore, this cleavage substantially increased the ability of the toxins to inhibit cellular protein synthesis. However, the toxins were unable to selectively eradicate HIV-1-infected cells, apparently due to low cytosolic HIV-1 PR activity, since we could not detect cleavage of the toxins by HIV-1 PR in infected cells. Alternative strategies for the construction of toxins that can specifically be activated by viral proteases are discussed.

scholarly journals A Novel Molecular Mechanism of Dual Resistance to Nucleoside and Nonnucleoside Reverse Transcriptase Inhibitors

2010 ◽  
Vol 84 (10) ◽  
pp. 5238-5249 ◽  
Author(s):  
Galina N. Nikolenko ◽  
Krista A. Delviks-Frankenberry ◽  
Vinay K. Pathak
Keyword(s):  
Reverse Transcriptase ◽  
Binding Pocket ◽  
Rnase H ◽  
Wild Type ◽  
Reverse Transcriptase Inhibitors ◽  
Nnrti Resistance ◽  
Nonnucleoside Reverse Transcriptase Inhibitors ◽  
Resistance Model ◽  
Hiv 1

ABSTRACT Recently, mutations in the connection subdomain (CN) and RNase H domain of HIV-1 reverse transcriptase (RT) were observed to exhibit dual resistance to nucleoside and nonnucleoside reverse transcriptase inhibitors (NRTIs and NNRTIs). To elucidate the mechanism by which CN and RH mutations confer resistance to NNRTIs, we hypothesized that these mutations reduce RNase H cleavage and provide more time for the NNRTI to dissociate from the RT, resulting in the resumption of DNA synthesis and enhanced NNRTI resistance. We observed that the effect of the reduction in RNase H cleavage on NNRTI resistance is dependent upon the affinity of each NNRTI to the RT and further influenced by the presence of NNRTI-binding pocket (BP) mutants. D549N, Q475A, and Y501A mutants, which reduce RNase H cleavage, enhance resistance to nevirapine (NVP) and delavirdine (DLV), but not to efavirenz (EFV) and etravirine (ETR), consistent with their increase in affinity for RT. Combining the D549N mutant with NNRTI BP mutants further increases NNRTI resistance from 3- to 30-fold, supporting the role of NNRTI-RT affinity in our NNRTI resistance model. We also demonstrated that CNs from treatment-experienced patients, previously reported to enhance NRTI resistance, also reduce RNase H cleavage and enhance NNRTI resistance in the context of the patient RT pol domain or a wild-type pol domain. Together, these results confirm key predictions of our NNRTI resistance model and provide support for a unifying mechanism by which CN and RH mutations can exhibit dual NRTI and NNRTI resistance.

scholarly journals Harmine enhances the activity of the HIV-1 latency-reversing agents ingenol A and SAHA

2020 ◽  
Author(s):  
Jared P. Taylor ◽  
Lucas H. Armitage ◽  
Daniel L. Aldridge ◽  
Melanie N. Cash ◽  
Mark A. Wallet
Keyword(s):  
Transcription Factors ◽  
Cell Model ◽  
Hdac Inhibitors ◽  
Negative Regulator ◽  
Viral Reactivation ◽  
Latent Reservoir ◽  
Transcriptional Elongation ◽  
Latently Infected ◽  
Infected Cells ◽  
Hiv 1

AbstractInfection of HIV-1 remains incurable because long-lived, latently-infected cells persist during prolonged antiretroviral therapy. Attempts to pharmacologically reactivate and purge the latent reservoir with latency reactivating agents (LRAs) such as protein kinase C (PKC) agonists (e.g. ingenol A) or histone deacetylase (HDAC) inhibitors (e.g. SAHA) have shown promising but incomplete efficacy. Using the J-Lat T cell model of HIV latency, we found that the plant-derived compound harmine enhanced the efficacy of existing PKC agonist LRAs in reactivating latently-infected cells. Treatment with harmine increased not only the number of reactivated cells but also increased HIV transcription and protein expression on a per-cell basis. Importantly, we observed an additive effect when harmine was used in combination with ingenol A and the HDAC inhibitor SAHA. An investigation into the mechanism revealed that harmine, when used with LRAs, increased the availability of transcription factors needed for viral reactivation such as NFκB, MAPK p38, and ERK1/2. We also found that harmine treatment resulted in reduced expression of HEXIM1, a negative regulator of transcriptional elongation. Despite harmine’s reported inhibitory effects on DYRK1A and consequent enhancement of NFAT signaling, the HIV reactivating effects of harmine occurred independent of DYRK1A and NFAT. Harmine increases the efficacy of LRAs by increasing the availability of HIV-1 transcription factors and decreasing expression of HEXIM1. Combination therapies with harmine and LRAs could benefit patients by achieving deeper reactivation of the latent pool of HIV provirus.

scholarly journals Dynamics and drivers of HIV-1 drug resistance to non-nucleoside reverse-transcriptase inhibitors in nine African countries

2020 ◽  
Author(s):  
Julien Riou ◽  
Carole Dupont ◽  
Silvia Bertagnolio ◽  
Ravindra Gupta ◽  
Roger D Kouyos ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Reverse Transcriptase ◽  
Survey Data ◽  
Southern Africa ◽  
Hiv Care ◽  
Reverse Transcriptase Inhibitors ◽  
Nucleoside Reverse Transcriptase Inhibitors ◽  
Nnrti Resistance ◽  
Country Level ◽  
Hiv 1

Background. The rise of HIV-1 drug resistance to non-nucleoside reverse-transcriptase inhibitors (NNRTI) is a major problem in countries of southern Africa. Understanding the dynamics and drivers of NNRTI resistance at the country level is of critical importance for planning future antiretroviral therapy (ART) programs. Methods. We collected survey data on pretreatment drug resistance (PDR) to NNRTIs in nine countries of southern Africa from 2000 to 2018. We fitted a dynamic transmission model to key indicators of the local HIV-1 epidemics (HIV-1 prevalence, ART coverage and mortality) and to survey data about NNRTI PDR using a Bayesian hierarchical framework. We estimated two country-level indicators: the proportion of NNRTI PDR that cannot be attributed to ART programmes and the vulnerability to NNRTI PDR within ART programmes. We explored associations between vulnerability to NNRTI PDR and country-level covariates.Findings. The model reliably described the dynamics of HIV-1 and the dynamics of NNRTI PDR in each country. Predicted levels of NNRTI PDR in 2018 ranged between 3.3% (95% credible interval 1.9% to 7.1%) in Mozambique and 25.3% (17.9% to 33.8%) in Eswatini. The main determinant of high NNRTI PDR were the conjunction of high ART coverage and high vulnerability to NNRTI PDR within ART programmes. Heterogeneity in the vulnerability to NNRTI resistance was associated with features of the healthcare financing system at the national level.Interpretation. Between-country comparison shows that NNRTI PDR can be controlled despite high levels of ART coverage, as in Botswana, Lesotho, Mozambique and Zambia, likely because of better adherence, patient management procedures and quality in HIV care service delivery.

scholarly journals Drivers of HIV-1 drug resistance to non-nucleoside reverse-transcriptase inhibitors (NNRTIs) in nine southern African countries: a modelling study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Julien Riou ◽  
Carole Dupont ◽  
Silvia Bertagnolio ◽  
Ravindra K. Gupta ◽  
Roger D. Kouyos ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Southern Africa ◽  
Transmission Model ◽  
Second Line ◽  
Fragility Index ◽  
Reverse Transcriptase Inhibitors ◽  
First Line ◽  
Nnrti Resistance ◽  
Dynamic Transmission Model ◽  
Hiv 1

Abstract Introduction The rise of HIV-1 drug resistance to non-nucleoside reverse-transcriptase inhibitors (NNRTI) threatens antiretroviral therapy's long-term success (ART). NNRTIs will remain an essential drug for the management of HIV-1 due to safety concerns associated with integrase inhibitors. We fitted a dynamic transmission model to historical data from 2000 to 2018 in nine countries of southern Africa to understand the mechanisms that have shaped the HIV-1 epidemic and the rise of pretreatment NNRTI resistance. Methods We included data on HIV-1 prevalence, ART coverage, HIV-related mortality, and survey data on pretreatment NNRTI resistance from nine southern Africa countries from a systematic review, UNAIDS and World Bank. Using a Bayesian hierarchical framework, we developed a dynamic transmission model linking data on the HIV-1 epidemic to survey data on NNRTI drug resistance in each country. We estimated the proportion of resistance attributable to unregulated, off-programme use of ART. We examined each national ART programme's vulnerability to NNRTI resistance by defining a fragility index: the ratio of the rate of NNRTI resistance emergence during first-line ART over the rate of switching to second-line ART. We explored associations between fragility and characteristics of the health system of each country. Results The model reliably described the dynamics of the HIV-1 epidemic and NNRTI resistance in each country. Predicted levels of resistance in 2018 ranged between 3.3% (95% credible interval 1.9–7.1) in Mozambique and 25.3% (17.9–33.8) in Eswatini. The proportion of pretreatment NNRTI resistance attributable to unregulated antiretroviral use ranged from 6% (2–14) in Eswatini to 64% (26–85) in Mozambique. The fragility index was low in Botswana (0.01; 0.0–0.11) but high in Namibia (0.48; 0.16–10.17), Eswatini (0.64; 0.23–11.8) and South Africa (1.21; 0.83–9.84). The combination of high fragility of ART programmes and high ART coverage levels was associated with a sharp increase in pretreatment NNRTI resistance. Conclusions This comparison of nine countries shows that pretreatment NNRTI resistance can be controlled despite high ART coverage levels. This was the case in Botswana, Mozambique, and Zambia, most likely because of better HIV care delivery, including rapid switching to second-line ART of patients failing first-line ART.

scholarly journals Harmine enhances the activity of the HIV-1 latency-reversing agents ingenol A and SAHA

Biology Open ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. bio052969
Author(s):  
Jared P. Taylor ◽  
Lucas H. Armitage ◽  
Daniel L. Aldridge ◽  
Melanie N. Cash ◽  
Mark A. Wallet
Keyword(s):  
Cell Model ◽  
Hdac Inhibitors ◽  
Negative Regulator ◽  
Latent Reservoir ◽  
Transcriptional Elongation ◽  
Hiv Transcription ◽  
Immunodeficiency Virus ◽  
Latently Infected ◽  
Infected Cells ◽  
Hiv 1

ABSTRACTInfection with human immunodeficiency virus 1 (HIV-1) remains incurable because long-lived, latently-infected cells persist during prolonged antiretroviral therapy. Attempts to pharmacologically reactivate and purge the latent reservoir with latency reactivating agents (LRAs) such as protein kinase C (PKC) agonists (e.g. ingenol A) or histone deacetylase (HDAC) inhibitors (e.g. SAHA) have shown promising but incomplete efficacy. Using the J-Lat T cell model of HIV latency, we found that the plant-derived compound harmine enhanced the efficacy of existing PKC agonist LRAs in reactivating latently-infected cells. Treatment with harmine increased not only the number of reactivated cells but also increased HIV transcription and protein expression on a per-cell basis. Importantly, we observed a synergistic effect when harmine was used in combination with ingenol A and the HDAC inhibitor SAHA. An investigation into the mechanism revealed that harmine, when used with LRAs, increased the activity of NFκB, MAPK p38, and ERK1/2. Harmine treatment also resulted in reduced expression of HEXIM1, a negative regulator of transcriptional elongation. Thus, harmine enhanced the effects of LRAs by increasing the availability of transcription factors needed for HIV reactivation and promoting transcriptional elongation. Combination therapies with harmine and LRAs could benefit patients by achieving deeper reactivation of the latent pool of HIV provirus.

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