Modulation of host gene expression by Hepatitis E virus ORF3 protein
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ABSTRACT: Analysis of human liver cell line (Huh7) infected with HEV ORF3 expressing (Ad-orf3-egfp) and control recombinant adenovirus (Ad-egfp). Hepatitis E virus ORF3 protein (pORF3) is known to modulate the host cell. Results provide insight into the role of this protein for HEV infection and pathogenesis.
Project description:Analysis of human liver cell line (Huh7) infected with HEV ORF3 expressing (Ad-orf3-egfp) and control recombinant adenovirus (Ad-egfp). Hepatitis E virus ORF3 protein (pORF3) is known to modulate the host cell. Results provide insight into the role of this protein for HEV infection and pathogenesis. The gene expression experiment of Huh7 hepatoma cell line infected with ORF3 expressing recombinant adenoviruses (Ad-orf3-egfp) and with control recombinant adenoviruses (Ad-egfp) was performed in replicates of three.
Project description:The hepatitis E virus (HEV), a non enveloped RNA virus, causes viral hepatitis. The viral open reading frame 2 (ORF2) protein represents the capsid protein of HEV which is known to cause endoplasmic reticulum stress in ORF2 expressing cells. The initiation of endoplasmic reticulum stress induced apoptosis mainly involves the transcriptional activation of pro-apoptotic gene CHOP which will further trigger the major apoptotic pathways. However, the activation of CHOP by ORF2 protein in this study does not induce apoptotic markers such as Bax translocation to mitochondria. We have used the Affymetrix microarray platform to screen the pro-apoptotic effects induced by the expression of ORF2 protein in human hepatic cell lines (Huh7). The Huh7 cells were transduced either with recombinant adenovirus encoding the HEV ORF2 (Ad-ORF2) or an adenovirus encoding the green fluorescent protein (Ad-GFP). The array results consistently showed an ORF2 specific induction of mRNA corresponding to the chaperones Hsp72, Hsp70B’ and co-chaperone Hsp40. These studies provide further mechanisms of the ER stress mediated pro apoptotic effects caused by the ORF2 protein and its potential role for the activation of anti-apoptotic activity of the host cell. We used microarray to screen the host genes were regulated by the expression of the hepatitis E virus capsid protein. Huh7 cells transduced with Ad-GFP (control) or with Ad-HEV ORF2.
Project description:The hepatitis E virus (HEV), a non enveloped RNA virus, causes viral hepatitis. The viral open reading frame 2 (ORF2) protein represents the capsid protein of HEV which is known to cause endoplasmic reticulum stress in ORF2 expressing cells. The initiation of endoplasmic reticulum stress induced apoptosis mainly involves the transcriptional activation of pro-apoptotic gene CHOP which will further trigger the major apoptotic pathways. However, the activation of CHOP by ORF2 protein in this study does not induce apoptotic markers such as Bax translocation to mitochondria. We have used the Affymetrix microarray platform to screen the pro-apoptotic effects induced by the expression of ORF2 protein in human hepatic cell lines (Huh7). The Huh7 cells were transduced either with recombinant adenovirus encoding the HEV ORF2 (Ad-ORF2) or an adenovirus encoding the green fluorescent protein (Ad-GFP). The array results consistently showed an ORF2 specific induction of mRNA corresponding to the chaperones Hsp72, Hsp70B’ and co-chaperone Hsp40. These studies provide further mechanisms of the ER stress mediated pro apoptotic effects caused by the ORF2 protein and its potential role for the activation of anti-apoptotic activity of the host cell.
Project description:Swine hepatits E (SHE) is a new type of zoonotic infectious disease caused by swine hepatitis E virus (SHEV). Open reading frame 3 (ORF3) is a key regulatory and virulent protein of SHEV. Circular RNA (circRNA) is a special kind of non-coding RNA molecule, which has a closed ring structure. In this study, to identify the circRNA profile in host cells affected by SHEV ORF3, adenovirus ADV4-ORF3 mediated the overexpression of ORF3 in HepG2 cells, high-throughput sequencing was used to investigate the differentially expressed circRNAs, GO and KEGG were performed to enrich the function of hosting genes, and Targetscan and miRanda softwares were used to analyze the interaction between circRNA and miRNA. In total, 1,105 up-regulation circRNAs and 1,556 down-regulation circRNAs were identified in ADV4-ORF3 infection group compared with the control. GO function enrichment analysis of differentially expressed circRNAs-hosting genes classified three main categories (cellular component, biological process and molecular function). KEGG pathway enrichment analysis scatter plot showed the pathway term of top20. Our findings first screened and analyzed the expression profile of circRNAs in HepG2 cells expressing genotype IV Swine Hepatitis E Virus ORF3, which may facilitate further study to reveal the function of SHEV ORF3 and molecular mechanism of SHEV infection.
Project description:Background & Aims: Other than hepatitis B or C virus infection, Hepatitis E virus (HEV) infection is generally asymptomatic or leads to acute and self-limiting hepatitis. However, the mechanism of host cell defense against HEV is unclear. Viruses are known to perturb host cellular metabolism to enable their replication and spread. AMP-activated protein kinase (AMPK) activation is crucial for the regulation of cell homeostasis. We thus investigated the role of AMPK in HEV infection. Methods: Huh7, THP1 and HepG2 cells inoculated with infectious HEV viral particle or Huh7 and organoids transfected with in vitro generated subgenomic or full-length GT3 (Kernow-C1 p6 strain) HEV RNA, namely, p6Luc or p6 were used to model HEV infection. Viral replication and genes expression were quantified. Activation of AMPK, innate immune response and autophagy process were assessed. Results: We found HEV infection can trigger AMPK activation by phosphorylation of AMPK at threonine 172 by transfecting HEV viral RNA into host cells or inoculating host cells with infectious HEV viral particle. The activation of AMPK is associated with HEV induced mitochondrial damage and ATP deficiency. Pharmacological activation of AMPK using 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) attenuated HEV replication, which was reversed by an AMPK inhibitor (compound C). Lentivirus-mediated knockdown of AMPK provided further evidence that AMPK has an antiviral effect on HEV replication. These results suggested that AMPK activation is a potent strategy of host cells for HEV clearance. Consistent with its antiviral effect, AMPK activation potentiated the expression of genes with antiviral properties (e.g., IFNs, ISG15, and IRF9) and inhibited inflammatory response (e.g., NF-KB NLRP3 and IL-1β). Meanwhile, HEV and activated AMPK also decreased autophagosome accumulation by decreasing induction of autophagy and autophagic degradation. Consistently, we found inhibition of AMPK efficiently augmented HEV induced autophagosome accumulation, evidenced by a marked increase in LC3II. Our previous study showed that rapamycin, an activator of autophagic induction by inhibiting mTOR, and Bafilomycin A1, an inhibitor of autophagic degradation, has a potent pro-HEV effect under AICAR treatment. Moreover, Wortmannin inhibiting autophagic induction recover AMPK inhibitor induced HEV replication. Together, these results suggested that HEV induced AMPK activation can serve to protect HEV infected cells from HEV infection by attenuating autophagosome and promoting innate immunity. Conclusions: Here we show that HEV infection can activate AMPK phosphorylation, which attenuates autophagosome accumulation and increases innate immune signaling. Thus, the AMPK activation in response to HEV infection is critical in host cells for rapid viral clearance by coordinating autophagic process and establishing persistent antiviral immunity.
Project description:Hepatitis E virus (HEV) is an important causative pathogen of acute hepatitis. Because of the absence of an in vitro culture system for HEV, research has been greatly impeded. And interaction between HEV and host cells was mainly studied by tansfection/transinfection system, such as Adeno virus transinfection system. We developed an in vitro culture system for HEV in PLC/PRF/5 cells. With this in vitro culture system, we studied the gene expression profile change by HEV infection. Using a microarray assay, we analysed genes of PLC/PRF/5 cells, whose transcription level could be changed by HEV infection.
Project description:Hepatitis E virus (HEV) is an important causative pathogen of acute hepatitis. Because of the absence of an in vitro culture system for HEV, research has been greatly impeded. And interaction between HEV and host cells was mainly studied by tansfection/transinfection system, such as Adeno virus transinfection system. We developed an in vitro culture system for HEV in PLC/PRF/5 cells. With this in vitro culture system, we studied the gene expression profile change by HEV infection. Using a microarray assay, we analysed genes of PLC/PRF/5 cells, whose transcription level could be changed by HEV infection. Five flasks of PLC/PRF/5 cells inoculated with HEV were used as test sample, and five flasks inoculated with serum-free DMEM/199 medium were used as control samples. Both test and control flasks were cultured under the same conditions. Sixty days after inoculation, the test and control flasks was resolved with Trizol and analysed with Affymetrix HG-U133 Plus 2 array.
Project description:Background: Human hepatitis E virus (HEV) usually causes a self-limiting disease, but especially immunocompromised individuals are at risk to develop a chronic and severe course of infection. Janus kinase (JAK) inhibitors (JAKi) are a novel drug class for the treatment of autoimmune inflammatory rheumatic disease (AIRD). As JAKs play a key role in innate immunity, viral infections and reactivations are frequently reported during JAKi treatment in AIRD patients. The aim of this study was to characterize the influence of JAKis on HEV replication in vivo and in authentic cell culture models ex vivo. Methods: We evaluated liver enzymes of an AIRD patient under JAKi therapy with hepatitis E and HEV infections in a cohort of AIRD patients. Experiments with HEV were performed by infection of primary human hepatocytes (PHHs) followed by immunofluorescence staining of viral markers and transcriptomic analysis. Results: Acute hepatitis was observed in a patient with AIRD and concomitant HEV infection. No acute infection could be detected in the AIRD cohort. Infection experiments in PHHs displayed an up to 50-fold increase of progeny virus production during JAKi treatment and transcriptomic analysis revealed induction of antiviral programs during infection. This induction was perturbed in the presence of JAKis, concomitant with elevated HEV RNA levels. Conclusion: Therapeutic JAK inhibition increases HEV replication by modulating the HEV-triggered immune response. Therefore, clinical monitoring of HEV infection during JAKi treatment and in case of elevated liver enzymes should be considered.
Project description:Background: Hepatitis E Virus (HEV) is a new causative agent of chronic hepatitis in solid organ transplant recipients in Europe. Factors associated with the occurrence and persistence of chronic HEV infection remain largely unknown but chronic evolution seems to be the consequence of hostM-bM-^@M-^Ys immunological factors rather than of viral factors. Method: In a prospective case-control study, we have determined in whole blood of chronically HEV-infected kidney-transplant recipients the host response using microarray technology. Results: Chronically HEV-infected kidney-transplant recipients exhibited a specific transcriptional program, in which interferon effectors were prominent. The intensity of expression of each signatureM-bM-^@M-^Ys gene was significantly lower in patients who were subsequently cleared of HEV than in patients who were not. Furthermore, in patients who were cleared of HEV, a higher expression of these genes was associated with a longer delay until HEV clearance. Conclusions: The specific transcriptional program determined in chronically HEV-infected kidney-transplant recipients suggests an activation of type I interferon response. Intensity of interferon-stimulated genes expression could be useful to forecast the outcome of infection. High expression of interferon-stimulated genes could signify a dysregulation in the interferon response that might favour the persistence of the HEV infection. TrialM-bM-^@M-^Ys registration number: NCT01090232; RegistryM-bM-^@M-^Ys URL: http://clinicaltrials.gov/ct2/show/study/NCT01090232?term=kidney+transplant+recipients&cntry1=EU%3AFR&rank=2 Total RNA was extracted from whole-blood sample or monocytes of kidney-transplant patients with or without chronic hepatitis E (CHE) infection. Control patients were matched up with CHE patients for age, sex, time since kidney transplant and immunosuppressive treatment.
Project description:Infection with hepatitis E virus (HEV) represents a global problem, with over 20 million people infected annually. No specific antiviral drugs are available for treating HEV infection, necessitating the development of novel targeted therapeutics. Here, we report that the N-methyl-D-aspartate receptor (NMDAR) antagonist ifenprodil, a clinically approved drug used to treat idiopathic pulmonary fibrosis (IPF), is an HEV inhibitor in liver-derived cells. In vitro investigation demonstrates that ifenprodil suppresses viral protein expression in a dose-dependent manner in human hepatoma cells by inhibiting early stages of viral infection. We also found that ifenprodil modulates host cell intrinsic biological processes distinct from virus-induced innate immunity, inhibiting HEV RNA accumulation in primary human hepatocytes. Finally, the inhibitory effect of ifenprodil in vivo was also tested in rabbits challenged with the HEV-3ra CHN-BJ-R14 strain. Fecal virus shedding was below the limit of detection in two animals for both ribavirin-treated and ifenprodil-treated rabbits compared to vehicle-treated control animals. Our data demonstrate that ifenprodil is an effective anti-HEV compound with potential as a therapeutic candidate for the treatment of HEV infection.