Zika virus(ZIKV)evolves non-structural proteins to evade immune response and ensure efficient replication in the host cells.Cholesterol metabolic enzyme 7-dehydrocholesterol reductase(DHCR7)was recently reported to im...Zika virus(ZIKV)evolves non-structural proteins to evade immune response and ensure efficient replication in the host cells.Cholesterol metabolic enzyme 7-dehydrocholesterol reductase(DHCR7)was recently reported to impact innate immune responses in ZIKV infection.However,the vital non-structural protein and mechanisms involved in DHCR7-mediated viral evasion are not well elucidated.In this study,we demonstrated that ZIKV infection facilitated DHCR7 expression.Notably,the upregulated DHCR7 in turn facilitated ZIKV infection and blocking DHCR7 suppressed ZIKV infection.Mechanically,ZIKV non-structural protein 4B(NS4B)interacted with DHCR7 to induce DHCR7 expression.Moreover,DHCR7 inhibited TANK-binding kinase 1(TBK1)and interferon regulatory factor 3(IRF3)phosphorylation,which resulted in the reduction of interferon-beta(IFN-β)and interferon-stimulated genes(ISGs)productions.Therefore,we propose that ZIKV NS4B binds to DHCR7 to repress TBK1 and IRF3 activation,which in turn inhibits IFN-βand ISGs,and thereby facilitating ZIKV evasion.This study broadens the insights on how viral non-structural proteins antagonize innate immunity to facilitate viral infection via cholesterol metabolic enzymes and intermediates.展开更多
Unlike human immunodeficiency virus(HIV)and hepatitis B virus(HBV),hepatitis C virus(HCV)infection is a curable disease.Current direct antiviral agent(DAA)targets are focused on HCV NS3/4A protein(protease),NS5 B prot...Unlike human immunodeficiency virus(HIV)and hepatitis B virus(HBV),hepatitis C virus(HCV)infection is a curable disease.Current direct antiviral agent(DAA)targets are focused on HCV NS3/4A protein(protease),NS5 B protein(polymerase)and NS5 A protein.The first generation of DAAs includes boceprevir and telaprevir,which are protease inhibitors and were approved for clinical use in2011.The cure rate for genotype 1 patients increased from 45% to 70% when boceprevir or telaprevir was added to standard PEG-IFN/ribavirin.More effective and less toxic second generation DAAs supplanted these drugs by 2013.The second generation of DAAs includes sofosbuvir(Sovaldi),simeprevir(Olysio),and fixed combination medicines Harvoni and Viekira Pak.These drugs increase cure rates to over 90%without the need for interferon and effectively treat all HCV genotypes.With these drugs the "cure HCV"goal has become a reality.Concerns remain about drug resistance mutations and the high cost of these drugs.The investigation of new HCV drugs is progressing rapidly;fixed dose combination medicines in phase III clinical trials include Viekirax,asunaprevirtdaclatasvirtbeclabuvir,grazoprevirtelbasvir and others.展开更多
基金supported by the National Natural Science Foundation of China(81730061,81802008)the Guangdong Basic and Applied Basic Research Foundation(2021A1515011272).
文摘Zika virus(ZIKV)evolves non-structural proteins to evade immune response and ensure efficient replication in the host cells.Cholesterol metabolic enzyme 7-dehydrocholesterol reductase(DHCR7)was recently reported to impact innate immune responses in ZIKV infection.However,the vital non-structural protein and mechanisms involved in DHCR7-mediated viral evasion are not well elucidated.In this study,we demonstrated that ZIKV infection facilitated DHCR7 expression.Notably,the upregulated DHCR7 in turn facilitated ZIKV infection and blocking DHCR7 suppressed ZIKV infection.Mechanically,ZIKV non-structural protein 4B(NS4B)interacted with DHCR7 to induce DHCR7 expression.Moreover,DHCR7 inhibited TANK-binding kinase 1(TBK1)and interferon regulatory factor 3(IRF3)phosphorylation,which resulted in the reduction of interferon-beta(IFN-β)and interferon-stimulated genes(ISGs)productions.Therefore,we propose that ZIKV NS4B binds to DHCR7 to repress TBK1 and IRF3 activation,which in turn inhibits IFN-βand ISGs,and thereby facilitating ZIKV evasion.This study broadens the insights on how viral non-structural proteins antagonize innate immunity to facilitate viral infection via cholesterol metabolic enzymes and intermediates.
文摘Unlike human immunodeficiency virus(HIV)and hepatitis B virus(HBV),hepatitis C virus(HCV)infection is a curable disease.Current direct antiviral agent(DAA)targets are focused on HCV NS3/4A protein(protease),NS5 B protein(polymerase)and NS5 A protein.The first generation of DAAs includes boceprevir and telaprevir,which are protease inhibitors and were approved for clinical use in2011.The cure rate for genotype 1 patients increased from 45% to 70% when boceprevir or telaprevir was added to standard PEG-IFN/ribavirin.More effective and less toxic second generation DAAs supplanted these drugs by 2013.The second generation of DAAs includes sofosbuvir(Sovaldi),simeprevir(Olysio),and fixed combination medicines Harvoni and Viekira Pak.These drugs increase cure rates to over 90%without the need for interferon and effectively treat all HCV genotypes.With these drugs the "cure HCV"goal has become a reality.Concerns remain about drug resistance mutations and the high cost of these drugs.The investigation of new HCV drugs is progressing rapidly;fixed dose combination medicines in phase III clinical trials include Viekirax,asunaprevirtdaclatasvirtbeclabuvir,grazoprevirtelbasvir and others.
