为了研究ifitm基因的功能,本研究从猪肾PK15细胞中克隆了猪的3个ifitm c DNA序列,分析了猪ifitm1、ifitm2和ifitm3基因的染色体定位及其与其他物种基因序列的同源关系,并对不同ifitm在不同组织的表达进行分析和检测。结果显示,猪ifitm...为了研究ifitm基因的功能,本研究从猪肾PK15细胞中克隆了猪的3个ifitm c DNA序列,分析了猪ifitm1、ifitm2和ifitm3基因的染色体定位及其与其他物种基因序列的同源关系,并对不同ifitm在不同组织的表达进行分析和检测。结果显示,猪ifitm和人、鼠ifitm具有相同的基因和蛋白结构,进化上与牛ifitm高度同源,ifitm1和ifitm3在脾、肾、心、肝等组织中大量表达,而ifitm2只在脾和肾中检测到表达,在其他组织中的表达量相对较小。猪ifitm基因的克隆、生物信息学及组织表达分析为进一步研究其在猪细胞中的功能奠定了基础。展开更多
丙型肝炎病毒(Hepatitis C Virus,HCV)是慢性丙型病毒性肝炎的主要病因,也是引发肝硬化和肝癌的主要诱因。在HCV感染过程中,伴随着干扰素信号通路的激活和干扰素刺激基因(IFN-stimulated gene,ISG)的持续表达,且有HCV独特的免疫逃逸和...丙型肝炎病毒(Hepatitis C Virus,HCV)是慢性丙型病毒性肝炎的主要病因,也是引发肝硬化和肝癌的主要诱因。在HCV感染过程中,伴随着干扰素信号通路的激活和干扰素刺激基因(IFN-stimulated gene,ISG)的持续表达,且有HCV独特的免疫逃逸和免疫细胞的功能损伤。现就HCV感染过程中机体的固有免疫反应和适应性免疫反应的研究进展作一综述。展开更多
AIM To investigate the effect of(-)-epigallocatechin-3-gallate(EGCG) on polyinosinic-polycytidylic acid(poly I:C)-triggered intracellular innate immunity against hepatitis C virus(HCV) in hepatocytes. METHODS A cell c...AIM To investigate the effect of(-)-epigallocatechin-3-gallate(EGCG) on polyinosinic-polycytidylic acid(poly I:C)-triggered intracellular innate immunity against hepatitis C virus(HCV) in hepatocytes. METHODS A cell culture model of HCV infection was generated by infecting a hepatoma cell line, Huh7, with HCV JFH-1 strain(JFH-1-Huh7). Poly I:C with a high molecular weight and EGCG were used to stimulate the JFH-1-Huh7 cells. Real-time reverse transcription-polymerase chain reaction was used to detect the expression levels of intracellular m RNAs and of intracellular and extracellular HCV RNA. Enzyme-linked immunosorbent assay was used to evaluate the interferon(IFN)-λ1 protein level in the cell culture supernatant. Immunostaining was used to examine HCV core protein expression in Huh7 cells.RESULTS Our recent study showed that HCV replication could impair poly I:C-triggered intracellular innate immune responses in hepatocytes. In the current study, we showed that EGCG treatment significantly increased the poly I:C-induced expression of Toll-like receptor 3(TLR3), retinoic acid-inducible gene I, and IFN-λ1 in JFH-1-Huh7 cells. In addition, supplementation with EGCG increased the poly I:C-mediated antiviral activity in JFH-1-Huh7 cells at the intracellular and extracellular HCV RNA and protein levels. Further investigation of the mechanisms showed that EGCG treatment significantly enhanced the poly I:C-induced expression of IFN-regulatory factor 9 and several antiviral IFNstimulated genes, including ISG15, ISG56, myxovirus resistance A, and 2'-5'-oligoadenylate synthetase 1, which encode the key antiviral elements in the IFN signaling pathway. CONCLUSION Our observations provide experimental evidence that EGCG has the ability to enhance poly I:C-induced intracellular antiviral innate immunity against HCV replication in hepatocytes.展开更多
Host interferon-stimulated gene 20(ISG20)exerts antiviral effects on viruses by degrading viral RNA or by enhancing IFN signaling.Here,we examined the role of ISG20 during pseudorabies virus(PRV)proliferation.We found...Host interferon-stimulated gene 20(ISG20)exerts antiviral effects on viruses by degrading viral RNA or by enhancing IFN signaling.Here,we examined the role of ISG20 during pseudorabies virus(PRV)proliferation.We found that ISG20 modulates PRV replication by enhancing IFN signaling.Further,ISG20 expression was upregulated following PRV infection and poly(I:C)treatment.Ectopic expression of ISG20 inhibited PRV proliferation in PK15 cells,whereas knockdown of ISG20 promoted PRV proliferation.In addition,ISG20 expression upregulated IFN-βexpression and enhanced IFN downstream signaling during PRV infection.Notably,PRV UL24 suppressed the transcription of ISG20,thus antagonizing its antiviral effect.Further domain mapping analysis showed that the N terminus(amino acids 1-90)of UL24 was responsible for the inhibition of ISG20 transcription.Collectively,these findings characterize the role of ISG20 in suppressing PRV replication and increase the understanding of host-PRV interplay.展开更多
ISG20 is an interferon-inducible exonuclease that inhibits virus replication.Although ISG20 is thought to degrade viral RNA,the antiviral mechanism and specificity of ISG20 remain unclear.In this study,the antiviral r...ISG20 is an interferon-inducible exonuclease that inhibits virus replication.Although ISG20 is thought to degrade viral RNA,the antiviral mechanism and specificity of ISG20 remain unclear.In this study,the antiviral role of ovine ISG20(o ISG20)in bluetongue virus(BTV)infection was investigated.It was found that BTV infection upregulated the transcription of ovine ISG20(o ISG20)in a time-and BTV multiplicity of infection(MOI)-dependent manner.Overexpression of o ISG20 suppressed the production of BTV genome,proteins,and virus titer,whereas the knockdown of o ISG20 increased viral replication.o ISG20 was found to co-localize with BTV proteins VP4,VP5,VP6,and NS2,but only directly interacted with VP4.Exonuclease defective o ISG20 significantly decreased the inhibitory effect on BTV replication.In addition,the interaction of mutant o ISG20 and VP4 was weakened,suggesting that binding to VP4 was associated with the inhibition of BTV replication.The present data characterized the anti-BTV effect of o ISG20,and provides a novel clue for further exploring the inhibition mechanism of double-stranded RNA virus by ISG20.展开更多
Hantaan virus(HTNV)is a rodent-borne virus that causes hemorrhagic fever with renal syndrome(HFRS),resulting in a high mortality rate of 15%.Interferons(IFNs)play a critical role in the anti-hantaviral immune response...Hantaan virus(HTNV)is a rodent-borne virus that causes hemorrhagic fever with renal syndrome(HFRS),resulting in a high mortality rate of 15%.Interferons(IFNs)play a critical role in the anti-hantaviral immune response,and IFN pretreatment efficiently restricts HTNV infection by triggering the expression of a series of IFNstimulated genes(ISGs)through the Janus kinase-signal transducer and activator of transcription 1(JAK-STAT)pathway.However,the tremendous amount of IFNs produced during late infection could not restrain HTNV replication,and the mechanism remains unclear.Here,we demonstrated that receptor-interacting protein kinase 3(RIPK3),a crucial molecule that mediates necroptosis,was activated by HTNV and contributed to hantavirus evasion of IFN responses by inhibiting STAT1 phosphorylation.RNA-seq analysis revealed the upregulation of multiple cell death-related genes after HTNV infection,with RIPK3 identified as a key modulator of viral replication.RIPK3 ablation significantly enhanced ISGs expression and restrained HTNV replication,without affecting the expression of pattern recognition receptors(PRRs)or the production of type I IFNs.Conversely,exogenously expressed RIPK3 compromised the host's antiviral response and facilitated HTNV replication.RIPK3^(-/-)mice also maintained a robust ability to clear HTNV with enhanced innate immune responses.Mechanistically,we found that RIPK3 could bind STAT1 and inhibit STAT1 phosphorylation dependent on the protein kinase domain(PKD)of RIPK3 but not its kinase activity.Overall,these observations demonstrated a noncanonical function of RIPK3 during viral infection and have elucidated a novel host innate immunity evasion strategy utilized by HTNV.展开更多
Bats are natural reservoir hosts for many viruses that produce no clinical symptoms in bats.Therefore, bats may have evolved effective mechanisms to control viral replication. However, little information is available ...Bats are natural reservoir hosts for many viruses that produce no clinical symptoms in bats.Therefore, bats may have evolved effective mechanisms to control viral replication. However, little information is available on bat immune responses to viral infection. Type I interferon(IFN) plays a key role in controlling viral infections. In this study, we report the cloning, expression, and biological activity of interferon β(IFNβ) from the Chinese microbat species, Myotis davidii. We demonstrated the upregulation of IFNB and IFN-stimulated genes in a kidney cell line derived from M. davidii after treatment with poly I:C or infection with Sendai virus. Furthermore, the recombinant IFNβ inhibited vesicular stomatitis virus and bat adenovirus replication in cell lines from two bat species, M. davidii and Rhinolophus sinicus. We provide the first in vitro evidence of IFNβ antiviral activity in microbats, which has important implications for virus interactions with these hosts.展开更多
Human endogenous retroviruses(HERVs) are the remains of ancient retroviruses that invaded our ancestors’ germline cell and were integrated into the genome. The expression of HERVs has always been a cause for concern ...Human endogenous retroviruses(HERVs) are the remains of ancient retroviruses that invaded our ancestors’ germline cell and were integrated into the genome. The expression of HERVs has always been a cause for concern because of its association with various cancers and diseases. However, few previous studies have focused on specific activation of HERVs by viral infections. Our previous study has shown that dengue virus type 2(DENV-2) infection induces the transcription of a large number of abnormal HERVs loci;therefore, the purpose of this study was to explore the relationship between exogenous viral infection and HERV activation further. In this study, we retrieved and reanalyzed published data on 21 transcriptomes of human cells infected with various viruses. We found that infection with different viruses could induce transcriptional activation of HERV loci. Through the comparative analysis of all viral datasets, we identified 43 key HERV loci that were up-regulated by DENV-2, influenza A virus, influenza B virus, Zika virus, measles virus, and West Nile virus infections. Furthermore, the neighboring genes of these HERVs were simultaneously up-regulated, and almost all such neighboring genes were interferon-stimulated genes(ISGs), which are enriched in the host’s antiviral immune response pathways. Our data supported the hypothesis that activation of HERVs, probably via an interferon-mediated mechanism, plays an important role in innate immunity against viral infections.展开更多
文摘为了研究ifitm基因的功能,本研究从猪肾PK15细胞中克隆了猪的3个ifitm c DNA序列,分析了猪ifitm1、ifitm2和ifitm3基因的染色体定位及其与其他物种基因序列的同源关系,并对不同ifitm在不同组织的表达进行分析和检测。结果显示,猪ifitm和人、鼠ifitm具有相同的基因和蛋白结构,进化上与牛ifitm高度同源,ifitm1和ifitm3在脾、肾、心、肝等组织中大量表达,而ifitm2只在脾和肾中检测到表达,在其他组织中的表达量相对较小。猪ifitm基因的克隆、生物信息学及组织表达分析为进一步研究其在猪细胞中的功能奠定了基础。
文摘丙型肝炎病毒(Hepatitis C Virus,HCV)是慢性丙型病毒性肝炎的主要病因,也是引发肝硬化和肝癌的主要诱因。在HCV感染过程中,伴随着干扰素信号通路的激活和干扰素刺激基因(IFN-stimulated gene,ISG)的持续表达,且有HCV独特的免疫逃逸和免疫细胞的功能损伤。现就HCV感染过程中机体的固有免疫反应和适应性免疫反应的研究进展作一综述。
基金Supported by the National Natural Science Foundation of China,No.81500449the Natural Science Foundation of Shanghai,No.14ZR1434200+2 种基金Shanghai Municipal Commission of Health and Family Planning,No.20144Y0175the Scientific Research Foundation for the Returned Overseas Chinese Scholarsthe State Education Ministry of China,No.20150909-6
文摘AIM To investigate the effect of(-)-epigallocatechin-3-gallate(EGCG) on polyinosinic-polycytidylic acid(poly I:C)-triggered intracellular innate immunity against hepatitis C virus(HCV) in hepatocytes. METHODS A cell culture model of HCV infection was generated by infecting a hepatoma cell line, Huh7, with HCV JFH-1 strain(JFH-1-Huh7). Poly I:C with a high molecular weight and EGCG were used to stimulate the JFH-1-Huh7 cells. Real-time reverse transcription-polymerase chain reaction was used to detect the expression levels of intracellular m RNAs and of intracellular and extracellular HCV RNA. Enzyme-linked immunosorbent assay was used to evaluate the interferon(IFN)-λ1 protein level in the cell culture supernatant. Immunostaining was used to examine HCV core protein expression in Huh7 cells.RESULTS Our recent study showed that HCV replication could impair poly I:C-triggered intracellular innate immune responses in hepatocytes. In the current study, we showed that EGCG treatment significantly increased the poly I:C-induced expression of Toll-like receptor 3(TLR3), retinoic acid-inducible gene I, and IFN-λ1 in JFH-1-Huh7 cells. In addition, supplementation with EGCG increased the poly I:C-mediated antiviral activity in JFH-1-Huh7 cells at the intracellular and extracellular HCV RNA and protein levels. Further investigation of the mechanisms showed that EGCG treatment significantly enhanced the poly I:C-induced expression of IFN-regulatory factor 9 and several antiviral IFNstimulated genes, including ISG15, ISG56, myxovirus resistance A, and 2'-5'-oligoadenylate synthetase 1, which encode the key antiviral elements in the IFN signaling pathway. CONCLUSION Our observations provide experimental evidence that EGCG has the ability to enhance poly I:C-induced intracellular antiviral innate immunity against HCV replication in hepatocytes.
基金supports from the National Key Research and Development Program of China(2016YFD0500100)Shanghai Science and Technology Innovation Action Plan(17391901900)Shanghai Municipal Agriculture Science and Technology Key Project(2016,4-2)。
文摘Host interferon-stimulated gene 20(ISG20)exerts antiviral effects on viruses by degrading viral RNA or by enhancing IFN signaling.Here,we examined the role of ISG20 during pseudorabies virus(PRV)proliferation.We found that ISG20 modulates PRV replication by enhancing IFN signaling.Further,ISG20 expression was upregulated following PRV infection and poly(I:C)treatment.Ectopic expression of ISG20 inhibited PRV proliferation in PK15 cells,whereas knockdown of ISG20 promoted PRV proliferation.In addition,ISG20 expression upregulated IFN-βexpression and enhanced IFN downstream signaling during PRV infection.Notably,PRV UL24 suppressed the transcription of ISG20,thus antagonizing its antiviral effect.Further domain mapping analysis showed that the N terminus(amino acids 1-90)of UL24 was responsible for the inhibition of ISG20 transcription.Collectively,these findings characterize the role of ISG20 in suppressing PRV replication and increase the understanding of host-PRV interplay.
基金the National Key Research and Development Program of China(2021YFD18005022017YFD0502304)+2 种基金National Natural Science Foundation of China(31672562)NBCITS(CARS-37)ASTIP(CAAS-ASTIP-2016-LVRI)。
文摘ISG20 is an interferon-inducible exonuclease that inhibits virus replication.Although ISG20 is thought to degrade viral RNA,the antiviral mechanism and specificity of ISG20 remain unclear.In this study,the antiviral role of ovine ISG20(o ISG20)in bluetongue virus(BTV)infection was investigated.It was found that BTV infection upregulated the transcription of ovine ISG20(o ISG20)in a time-and BTV multiplicity of infection(MOI)-dependent manner.Overexpression of o ISG20 suppressed the production of BTV genome,proteins,and virus titer,whereas the knockdown of o ISG20 increased viral replication.o ISG20 was found to co-localize with BTV proteins VP4,VP5,VP6,and NS2,but only directly interacted with VP4.Exonuclease defective o ISG20 significantly decreased the inhibitory effect on BTV replication.In addition,the interaction of mutant o ISG20 and VP4 was weakened,suggesting that binding to VP4 was associated with the inhibition of BTV replication.The present data characterized the anti-BTV effect of o ISG20,and provides a novel clue for further exploring the inhibition mechanism of double-stranded RNA virus by ISG20.
基金This work was supported in whole or in part by the National Natural Science Foundation of China(82172272,31970148 and 82222367)the Key Research and Development Program of Shaanxi(2021ZDLSF01-05 and 2021ZDLSF01-02).
文摘Hantaan virus(HTNV)is a rodent-borne virus that causes hemorrhagic fever with renal syndrome(HFRS),resulting in a high mortality rate of 15%.Interferons(IFNs)play a critical role in the anti-hantaviral immune response,and IFN pretreatment efficiently restricts HTNV infection by triggering the expression of a series of IFNstimulated genes(ISGs)through the Janus kinase-signal transducer and activator of transcription 1(JAK-STAT)pathway.However,the tremendous amount of IFNs produced during late infection could not restrain HTNV replication,and the mechanism remains unclear.Here,we demonstrated that receptor-interacting protein kinase 3(RIPK3),a crucial molecule that mediates necroptosis,was activated by HTNV and contributed to hantavirus evasion of IFN responses by inhibiting STAT1 phosphorylation.RNA-seq analysis revealed the upregulation of multiple cell death-related genes after HTNV infection,with RIPK3 identified as a key modulator of viral replication.RIPK3 ablation significantly enhanced ISGs expression and restrained HTNV replication,without affecting the expression of pattern recognition receptors(PRRs)or the production of type I IFNs.Conversely,exogenously expressed RIPK3 compromised the host's antiviral response and facilitated HTNV replication.RIPK3^(-/-)mice also maintained a robust ability to clear HTNV with enhanced innate immune responses.Mechanistically,we found that RIPK3 could bind STAT1 and inhibit STAT1 phosphorylation dependent on the protein kinase domain(PKD)of RIPK3 but not its kinase activity.Overall,these observations demonstrated a noncanonical function of RIPK3 during viral infection and have elucidated a novel host innate immunity evasion strategy utilized by HTNV.
基金funded by the National Natural Science Foundation of China (No. 31321001)
文摘Bats are natural reservoir hosts for many viruses that produce no clinical symptoms in bats.Therefore, bats may have evolved effective mechanisms to control viral replication. However, little information is available on bat immune responses to viral infection. Type I interferon(IFN) plays a key role in controlling viral infections. In this study, we report the cloning, expression, and biological activity of interferon β(IFNβ) from the Chinese microbat species, Myotis davidii. We demonstrated the upregulation of IFNB and IFN-stimulated genes in a kidney cell line derived from M. davidii after treatment with poly I:C or infection with Sendai virus. Furthermore, the recombinant IFNβ inhibited vesicular stomatitis virus and bat adenovirus replication in cell lines from two bat species, M. davidii and Rhinolophus sinicus. We provide the first in vitro evidence of IFNβ antiviral activity in microbats, which has important implications for virus interactions with these hosts.
基金This work was supported by the China Ministry of Science and Technology Key Research&Development Program(No.2016YFC1200800)the National Natural Science Foundation of China(No.91631110)the National Mega Project on Major Infectious Disease Prevention(No.2017ZX10103005-005)。
文摘Human endogenous retroviruses(HERVs) are the remains of ancient retroviruses that invaded our ancestors’ germline cell and were integrated into the genome. The expression of HERVs has always been a cause for concern because of its association with various cancers and diseases. However, few previous studies have focused on specific activation of HERVs by viral infections. Our previous study has shown that dengue virus type 2(DENV-2) infection induces the transcription of a large number of abnormal HERVs loci;therefore, the purpose of this study was to explore the relationship between exogenous viral infection and HERV activation further. In this study, we retrieved and reanalyzed published data on 21 transcriptomes of human cells infected with various viruses. We found that infection with different viruses could induce transcriptional activation of HERV loci. Through the comparative analysis of all viral datasets, we identified 43 key HERV loci that were up-regulated by DENV-2, influenza A virus, influenza B virus, Zika virus, measles virus, and West Nile virus infections. Furthermore, the neighboring genes of these HERVs were simultaneously up-regulated, and almost all such neighboring genes were interferon-stimulated genes(ISGs), which are enriched in the host’s antiviral immune response pathways. Our data supported the hypothesis that activation of HERVs, probably via an interferon-mediated mechanism, plays an important role in innate immunity against viral infections.
