Phosphatidylinositol‐4 kinase III beta and oxysterol‐binding protein accumulate unesterified cholesterol on poliovirus‐induced membrane structure

Arita, Minetaro

doi:10.1111/1348-0421.12144

Cited by 97 publications

(127 citation statements)

References 54 publications

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“…It was recently proposed that OSBP is recruited to the HCV MW in a PI4KIII␣-dependent manner and that both factors are required for cholesterol trafficking to the MW (27). A similar PI4KIII␤-dependent mechanism has been proposed very recently for poliovirus (59). In this study, we observed that NS5A inhibitors, like PI4KIII␣ inhibitors, cause a decrease in PI4P concentration, concomitantly with a decrease in cholesterol levels in the endomembrane structures of HCV-replicating cells (Fig.…”

Section: Discussionsupporting

confidence: 84%

NS5A Inhibitors Impair NS5A–Phosphatidylinositol 4-Kinase IIIα Complex Formation and Cause a Decrease of Phosphatidylinositol 4-Phosphate and Cholesterol Levels in Hepatitis C Virus-Associated Membranes

Reghellin

Donnici

Fenu

et al. 2014

Antimicrob Agents Chemother

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bThe hepatitis C virus (HCV) nonstructural (NS) protein 5A is a multifunctional protein that plays a central role in viral replication and assembly. Antiviral agents directly targeting NS5A are currently in clinical development. Although the elucidation of the mechanism of action (MOA) of NS5A inhibitors has been the focus of intensive research, a detailed understanding of how these agents exert their antiviral effect is still lacking. In this study, we observed that the downregulation of NS5A hyperphosphorylation is associated with the actions of NS5A inhibitors belonging to different chemotypes. NS5A is known to recruit the lipid kinase phosphatidylinositol 4-kinase III␣ (PI4KIII␣) to the HCV-induced membranous web in order to generate phosphatidylinositol 4-phosphate (PI4P) at the sites of replication. We demonstrate that treatment with NS5A inhibitors leads to an impairment in the NS5A-PI4KIII␣ complex formation that is paralleled by a significant reduction in PI4P and cholesterol levels within the endomembrane structures of HCV-replicating cells. A similar decrease in PI4P and cholesterol levels was also obtained upon treatment with a PI4KIII␣-targeting inhibitor. In addition, both the NS5A and PI4KIII␣ classes of inhibitors induced similar subcellular relocalization of the NS5A protein, causing the formation of large cytoplasmic NS5A-containing clusters previously reported to be one of the hallmarks of inhibition of the action of PI4KIII␣. Because of the similarities between the effects induced by treatment with PI4KIII␣ or NS5A inhibitors and the observation that agents targeting NS5A impair NS5A-PI4KIII␣ complex formation, we speculate that NS5A inhibitors act by interfering with the function of the NS5A-PI4KIII␣ complex.T he recent advent of direct-acting antivirals (DAAs) against hepatitis C virus (HCV) is radically transforming the treatment scenario for patients with chronic hepatitis C infection. These new drugs offer the promise of well-tolerated interferonfree oral regimens that are able to cure the majority of infected patients (1).Initially, the effort to identify DAAs focused primarily on inhibitors of two virally encoded enzymes: the nonstructural 3/4A (NS3/4A) protease and the NS5B polymerase. More recently, however, the clinical validation of NS5A inhibitors (2) has generated increasing interest in this target class. The first NS5A inhibitors were discovered by a phenotypic screen based on the genotype 1b replicon system (3, 4). The initial lead compounds had moderate potency and a narrow spectrum of anti-HCV activity, mainly on genotype 1b. Subsequent medicinal chemistry efforts (4) resulted in the design of picomolar inhibitors characterized by a peculiar and highly symmetrical dimeric structure (reviewed in reference 5). The most-studied agent of this "palindromic" NS5A inhibitor class is daclatasvir (DCV, formerly BMS-790052) (6), a highly optimized biphenyl derivative inhibitor for which regulatory approval is currently being sought.Different chemical isotypes were initially claimed to ...

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Section: Discussionsupporting

confidence: 84%

NS5A Inhibitors Impair NS5A–Phosphatidylinositol 4-Kinase IIIα Complex Formation and Cause a Decrease of Phosphatidylinositol 4-Phosphate and Cholesterol Levels in Hepatitis C Virus-Associated Membranes

Reghellin

Donnici

Fenu

et al. 2014

Antimicrob Agents Chemother

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“…5A). Cross-resistance of the 3A[H57Y] mutant to PI4KIIIb inhibitors and OSW-1 suggests that PI4KIIIb and OSBP act in the same pathway and is in line with previous reports that OSBP is recruited by PI4KIIIb-generated PI4P (Arita, 2014;Arita et al, 2013;Roulin et al, 2014).…”

Section: Introductionsupporting

confidence: 90%

“…Replication organelles of enteroviruses are enriched in PI4P lipids produced by PI4KIIIb (Hsu et al, 2010). Recently, oxysterol-binding protein (OSBP), a PI4P-binding protein that shuttles cholesterol between membrane compartments, was implicated as another host factor for enterovirus replication (Arita, 2014;Arita et al, 2013;Roulin et al, 2014;Wang et al, 2014). Fig.…”

Section: Introductionmentioning

confidence: 99%

Broad-range inhibition of enterovirus replication by OSW-1, a natural compound targeting OSBP

et al. 2015

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Enteroviruses, e.g., polio-, coxsackie-and rhinoviruses, constitute a large genus within the Picornaviridae family of positive-strand RNA viruses and include many important pathogens linked to a variety of acute and chronic diseases. Despite their huge medical and economic impact, no approved antiviral therapy is yet available. Recently, the oxysterol-binding protein (OSBP) was implicated as a host factor for enterovirus replication. Here, we investigated the antiviral activity of the natural compound OSW-1, a ligand of OSBP that is under investigation as an anti-cancer drug. OSW-1 potently inhibited the replication of all enteroviruses tested, with IC50 values in the low nanomolar range, acted at the genome replication stage and was effective in all tested cell types of three different species. Importantly, OSBP overexpression rescued viral replication, demonstrating that the antiviral effect of OSW-1 is due to targeting OSBP. Together, we here report the anti-enterovirus activity of the natural anti-cancer compound OSW-1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 Enteroviruses form a large genus belonging to the Picornaviridae family of positive-strand RNA viruses [(+)RNA] and include important human pathogens. Enteroviral infections have been implicated in a number of acute and chronic diseases, ranging from poliomyelitis (poliovirus), meningoencephalitis and myocarditis (coxsackieviruses and echoviruses), and common cold to asthma exacerbation and chronic obstructive pulmonary disease (rhinoviruses). Poliovirus is the only member of the genus for which an efficient vaccine is available and no antiviral therapy is currently approved for treating enteroviral infections. OSW-1 is a natural compound extracted from the bulbs of the plant Ornithogalum saundersiae that has been studied mainly for its anti-cancer activity. Burgett et al. (2011) identified OSBP as a high-affinity target of OSW-1 using affinity chromatography and demonstrated that OSW-1 exerts its anti-cancer activity via OSBP.In this study, we investigated the antiviral activity of OSW-1. We assessed the effect of OSW-1 on a single-round of infection of HeLa or Buffalo Green Monkey (BGM) kidney cells by viruses from different species in the Enterovirus genus, i.e., enterovirus 71 (EV71, enterovirus A species), coxsackievirus A21 (CVA21, enterovirus C species), human rhinovirus 2 (HRV2, rhinovirus A species) and human rhinovirus 14 (HRV-14, rhinovirus B species). All enteroviruses tested were sensitive to OSW-1, with IC50 values ranging between 2.4 and 9.4 nM ( Fig. 1A-E). Cell viability assays performed in parallel revealed no cytotoxicity (CC50 > 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 ...

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“…Such changes could result in (i) accumulation of membrane structures used for poliovirus RNA replication, (ii) enhancement of virus release, and/or (iii) viral evasion of host immune responses (19,(32)(33)(34). As enterovirus replication requires the accumulation of phosphatidylinositol-4-phosphate (PI4P) lipids and unesterified cholesterol on membrane structures (35,36), the possible role for the BTN2A1 gene discovered in this study is becoming clearer due to its known involvement in lipid metabolism. Studies are in progress to unravel the mechanisms of action for all of the validated genes discovered in this study.…”

Section: Discussionmentioning

confidence: 80%

Engineering Enhanced Vaccine Cell Lines To Eradicate Vaccine-Preventable Diseases: the Polio End Game

Sanden

Wang

Dybdahl‐Sissoko

et al. 2016

J Virol

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Vaccine manufacturing costs prevent a significant portion of the world's population from accessing protection from vaccinepreventable diseases. To enhance vaccine production at reduced costs, a genome-wide RNA interference (RNAi) screen was performed to identify gene knockdown events that enhanced poliovirus replication. Primary screen hits were validated in a Vero vaccine manufacturing cell line using attenuated and wild-type poliovirus strains. Multiple single and dual gene silencing events increased poliovirus titers >20-fold and >50-fold, respectively. Host gene knockdown events did not affect virus antigenicity, and clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9-mediated knockout of the top candidates dramatically improved viral vaccine strain production. Interestingly, silencing of several genes that enhanced poliovirus replication also enhanced replication of enterovirus 71, a clinically relevant virus to which vaccines are being targeted. The discovery that host gene modulation can markedly increase virus vaccine production dramatically alters mammalian cell-based vaccine manufacturing possibilities and should facilitate polio eradication using the inactivated poliovirus vaccine. IMPORTANCEUsing a genome-wide RNAi screen, a collection of host virus resistance genes was identified that, upon silencing, increased poliovirus and enterovirus 71 production by from 10-fold to >50-fold in a Vero vaccine manufacturing cell line. This report provides novel insights into enterovirus-host interactions and describes an approach to developing the next generation of vaccine manufacturing through engineered vaccine cell lines. The results show that specific gene silencing and knockout events can enhance viral titers of both attenuated (Sabin strain) and wild-type polioviruses, a finding that should greatly facilitate global implementation of inactivated polio vaccine as well as further reduce costs for live-attenuated oral polio vaccines. This work describes a platform-enabling technology applicable to most vaccine-preventable diseases. Vaccines are important defenses in the fight against infectious disease. Currently, a complex set of factors such as population dynamics and bioproduction costs limit the ability to provide adequate immunization coverage to many economically distressed countries. The current efforts to eradicate poliovirus exemplify these challenges. The oral polio vaccine (OPV), consisting of attenuated Sabin strains, has reduced the total number of poliomyelitis cases by Ͼ99% since the late 1980s. However, live attenuated strains carry the risk of phenotypic reversion to a neurovirulent "vaccine-derived poliovirus" (VDPV) capable of inducing vaccine-associated paralytic poliomyelitis (VAPP) (1, 2). To prevent the emergence and circulation of VDPVs during the polio eradication effort and beyond, OPV must be replaced by the inactivated poliovirus vaccine (IPV) (3). The cost of IPV, which is approximately $3.00 per dose compared to approximately $0.20 for OPV, is a major o...

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Phosphatidylinositol‐4 kinase III beta and oxysterol‐binding protein accumulate unesterified cholesterol on poliovirus‐induced membrane structure

Cited by 97 publications

References 54 publications

NS5A Inhibitors Impair NS5A–Phosphatidylinositol 4-Kinase IIIα Complex Formation and Cause a Decrease of Phosphatidylinositol 4-Phosphate and Cholesterol Levels in Hepatitis C Virus-Associated Membranes

NS5A Inhibitors Impair NS5A–Phosphatidylinositol 4-Kinase IIIα Complex Formation and Cause a Decrease of Phosphatidylinositol 4-Phosphate and Cholesterol Levels in Hepatitis C Virus-Associated Membranes

Broad-range inhibition of enterovirus replication by OSW-1, a natural compound targeting OSBP

Engineering Enhanced Vaccine Cell Lines To Eradicate Vaccine-Preventable Diseases: the Polio End Game

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