AIM： To study the effect of Hepatitis C virus nonstructural 5A （HCV NSSA） on IFNα induced signal transducer and activator of transcription-1 （STAT1） phosphorylation and nuclear translocation.METHODS： Expression...AIM： To study the effect of Hepatitis C virus nonstructural 5A （HCV NSSA） on IFNα induced signal transducer and activator of transcription-1 （STAT1） phosphorylation and nuclear translocation.METHODS： Expression of STAT1 Tyr701 phosphorylation at different time points was confirmed by Western blot, and the time point when p-STAT1 expressed most, was taken as the IFN induction time for further studies. Immunocytochemistry was used to confirm the successful transient transfection of NS5A expression plasmid. Immunofluorescene was performed to observe if there was any difference in IFNα-induced STAT1 phosphorylation and nuclear translocation between HCV NSSA-expressed and non-HCV NSSA-expressed cells. Western blot was used to compare the phosphorylated STAT1 protein of the cells.RESULTS： Expression of HCV NS5A was found in the cytoplasm of pCNS5A-transfected Huh7 cells, but not in the PRC/ CMV transfected or non-transfected cells, STAT1 Tyr701 phosphorylation was found strongest in 30 min of IFN induction, STAT1 phosphorylation and nuclear import were much less in the presence of HCV NS5A protein in contrast to pRC/CMV-transfected and non-transfected cells under fluorescent microscopy, which was further confirmed by Western blot.CONCLUSION： HCV NSSA expression plasmid is successfully transfected into Huh7 cells and HCV NS5A protein is expressed in the cytoplasm of the cells. IFN-α is able to induce STAT1 phosphrylation and nuclear translocation, and this effect is inhibited by HCV NS5A protein, which might be another possible resistance mechanism to interferon alpha therapy.展开更多
The immune effect of two recombinant protein fragments of spike protein in severe acute respiratory syndrome coronavirus (SARS CoV) was investigated in Balb/c mice. Two partial spike gene fragments S1 (322-1464 bp) an...The immune effect of two recombinant protein fragments of spike protein in severe acute respiratory syndrome coronavirus (SARS CoV) was investigated in Balb/c mice. Two partial spike gene fragments S1 (322-1464 bp) and S2 (2170-2814 bp) of SARS coronavirus were amplified by RT-PCR, and cloned into pET-23a prokaryotic expression vector, then transformed into competent Escherichia E.coli BL21 (DE3)(pLysS) respectively. Recombinant proteins were expressed and puri- fied by Ni2+ immobilized metal ion affinity chromatography. The purified proteins mixed with com- plete Freund adjuvant were injected into Balb/c mice three times at a two-week interval. High titer antibody was detected in the serum of immunized Balb/c mice, and mice immunized with S1 protein produced high titer IgG1, IgG2a, IgG2b and IgG3, while those immunized with S2 protein produced high titer IgG1, IgG2a, but lower titer IgG2b and IgG3. Serum IFN-γ concentration was increased significantly but the concentrations of IL-2, IL-4 and IL-10 had no significant change. And a marked increase was observed in the number of spleen CD8+ T cells. The results showed that recombinant proteins of SARS coronavirus spike protein induced hormonal and cellular immune response in Balb/c mice.展开更多
Porcine epidemic diarrhea virus（PEDV） is a highly infectious pathogen that can cause severe diseases in pigs and result in enormous economic losses in the worldwide swine industry. Previous studies revealed that PED...Porcine epidemic diarrhea virus（PEDV） is a highly infectious pathogen that can cause severe diseases in pigs and result in enormous economic losses in the worldwide swine industry. Previous studies revealed that PEDV exhibits an obvious capacity for modulating interferon（IFN） signaling or expression. The newly discovered type III IFN, which plays a crucial role in antiviral immunity, has strong antiviral activity against PEDV proliferation in IPEC-J2 cells. In this study, we aimed to investigate the effect of PEDV nucleocapsid（N） protein on type III IFN-λ. We found that the N proteins of ten PEDV strains isolated between 2013 and 2017 from different local farms shared high nucleotide identities, while the N protein of the CV777 vaccine strain formed a monophyletic branch in the phylogenetic tree. The N protein of the epidemic strain could antagonize type III IFN, but not type I or type II IFN expression induced by polyinosinic-polycytidylic acid（poly（I：C）） in IPEC-J2 cells. Subsequently, we demonstrated that the inhibition of poly（I：C）-induced IFN-λ3 production by PEDV N protein was dependent on the blocking of nuclear factor-κB（NF-κB） nuclear translocation. These findings might help increase understanding of the pathogenesis of PEDV and its mechanisms for evading the host immune response.展开更多
Aim: The expression of the cytokines IL-2, IL-6, IL-10, IFN-γ and TNF-α and the adhesion proteins CD99 and CD106 was studied in the human testis at the protein level. Methods: The expression of the cytokines and the...Aim: The expression of the cytokines IL-2, IL-6, IL-10, IFN-γ and TNF-α and the adhesion proteins CD99 and CD106 was studied in the human testis at the protein level. Methods: The expression of the cytokines and the adhesion proteins was assessed using immunohistochemistry and immunoblotting. Results: None of the cytokines studied was present in the human testis, but CD99 and CD106 (VCAM-1) strongly were expressed in all the testes investigated. CD99 was present in the interstitial tissue of the human testis as well as in the Sertoli cells. The identity of the CD99+ interstitial cells is unclear. CD106 (VCAM-1) was present in Leydig cells as well as the basal parts of the Sertoli cells in the seminiferous tubules. In immunoblotting, CD99 was demonstrated at molecular ratios of 46-57 (kD). This is a novel isoform of the molecule. Conclusion: The human testis produces both CD99 and CD106 and as CD106 mediates cell binding to lymphocytes, it is possible that the human Leydig cells adhere to lymphocytes like the rodent Leydig cells. (Asian J Androl 2002 Dec; 4: 243-248)展开更多
Background and aim:a-complex protein-2(aCP2)encoded by the poly(rC)binding protein 2(PCBP2)gene is responsible for the accumulation of type I collagen in fibrotic livers.In this study,we silenced the PCBP2 gene using ...Background and aim:a-complex protein-2(aCP2)encoded by the poly(rC)binding protein 2(PCBP2)gene is responsible for the accumulation of type I collagen in fibrotic livers.In this study,we silenced the PCBP2 gene using a small interfering RNA(siRNA)to reverse alcohol-and cytokine-induced profibrogenic effects on hepatic stellate cells(HSCs).Methods:Primary rat HSCs and the HSC-T6 cell line were used as fibrogenic models to mimic the initiation and perpetuation stages of fibrogenesis,respectively.We previously found that a PCBP2 siRNA,which efficiently silences expression of aCP2,reduces the stability of type I collagen mRNA.We investigated the effects of the PCBP2 siRNA on cell proliferation and migration.Expression of type I collagen in HSCs was analyzed by quantitative real-time PCR and western blotting.In addition,we evaluated the effects of the PCBP2 siRNA on apoptosis and the cell cycle.Results:PCBP2 siRNA reversed multiple alcohol-and cytokine-induced profibrogenic effects on primary rat HSCs and HSC-T6 cells.The PCBP2 siRNA also reversed alcohol-and cytokine-induced accumulation of type I collagen as well as cell proliferation and migration.Moreover,the combination of LY2109761,a transforming growth factor-b1 inhibitor,and the PCBP2 siRNA exerted a synergistic inhibitive effect on the accumulation of type I collagen in HSCs.Conclusions:Silencing of PCBP2 using siRNA could be a potential therapeutic strategy for alcoholic liver fibrosis.展开更多
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
基金Supported by National Natural Science Foundation of ChinaNo. 39670671, No. 30471531
文摘AIM： To study the effect of Hepatitis C virus nonstructural 5A （HCV NSSA） on IFNα induced signal transducer and activator of transcription-1 （STAT1） phosphorylation and nuclear translocation.METHODS： Expression of STAT1 Tyr701 phosphorylation at different time points was confirmed by Western blot, and the time point when p-STAT1 expressed most, was taken as the IFN induction time for further studies. Immunocytochemistry was used to confirm the successful transient transfection of NS5A expression plasmid. Immunofluorescene was performed to observe if there was any difference in IFNα-induced STAT1 phosphorylation and nuclear translocation between HCV NSSA-expressed and non-HCV NSSA-expressed cells. Western blot was used to compare the phosphorylated STAT1 protein of the cells.RESULTS： Expression of HCV NS5A was found in the cytoplasm of pCNS5A-transfected Huh7 cells, but not in the PRC/ CMV transfected or non-transfected cells, STAT1 Tyr701 phosphorylation was found strongest in 30 min of IFN induction, STAT1 phosphorylation and nuclear import were much less in the presence of HCV NS5A protein in contrast to pRC/CMV-transfected and non-transfected cells under fluorescent microscopy, which was further confirmed by Western blot.CONCLUSION： HCV NSSA expression plasmid is successfully transfected into Huh7 cells and HCV NS5A protein is expressed in the cytoplasm of the cells. IFN-α is able to induce STAT1 phosphrylation and nuclear translocation, and this effect is inhibited by HCV NS5A protein, which might be another possible resistance mechanism to interferon alpha therapy.
文摘The immune effect of two recombinant protein fragments of spike protein in severe acute respiratory syndrome coronavirus (SARS CoV) was investigated in Balb/c mice. Two partial spike gene fragments S1 (322-1464 bp) and S2 (2170-2814 bp) of SARS coronavirus were amplified by RT-PCR, and cloned into pET-23a prokaryotic expression vector, then transformed into competent Escherichia E.coli BL21 (DE3)(pLysS) respectively. Recombinant proteins were expressed and puri- fied by Ni2+ immobilized metal ion affinity chromatography. The purified proteins mixed with com- plete Freund adjuvant were injected into Balb/c mice three times at a two-week interval. High titer antibody was detected in the serum of immunized Balb/c mice, and mice immunized with S1 protein produced high titer IgG1, IgG2a, IgG2b and IgG3, while those immunized with S2 protein produced high titer IgG1, IgG2a, but lower titer IgG2b and IgG3. Serum IFN-γ concentration was increased significantly but the concentrations of IL-2, IL-4 and IL-10 had no significant change. And a marked increase was observed in the number of spleen CD8+ T cells. The results showed that recombinant proteins of SARS coronavirus spike protein induced hormonal and cellular immune response in Balb/c mice.
基金Project supported by the National Natural Science Foundation of China(No.31702250)the Key Research and Development Project Funds of Zhejiang Provincial Science and Technology Department(Nos.2015C02044 and 2018C02028)+2 种基金the Agricultural Technology Extension Funds of Zhejiang Universitythe Dabei Agricultural Discipline Development and Talent Training Fund(No.2017ZDNT004)the Three Rural and Six Party Funds,China
文摘Porcine epidemic diarrhea virus（PEDV） is a highly infectious pathogen that can cause severe diseases in pigs and result in enormous economic losses in the worldwide swine industry. Previous studies revealed that PEDV exhibits an obvious capacity for modulating interferon（IFN） signaling or expression. The newly discovered type III IFN, which plays a crucial role in antiviral immunity, has strong antiviral activity against PEDV proliferation in IPEC-J2 cells. In this study, we aimed to investigate the effect of PEDV nucleocapsid（N） protein on type III IFN-λ. We found that the N proteins of ten PEDV strains isolated between 2013 and 2017 from different local farms shared high nucleotide identities, while the N protein of the CV777 vaccine strain formed a monophyletic branch in the phylogenetic tree. The N protein of the epidemic strain could antagonize type III IFN, but not type I or type II IFN expression induced by polyinosinic-polycytidylic acid（poly（I：C）） in IPEC-J2 cells. Subsequently, we demonstrated that the inhibition of poly（I：C）-induced IFN-λ3 production by PEDV N protein was dependent on the blocking of nuclear factor-κB（NF-κB） nuclear translocation. These findings might help increase understanding of the pathogenesis of PEDV and its mechanisms for evading the host immune response.
基金Correspondence to: Dr. Esko Verijnkorva, University of Turku, Institute of Biomedicine, Department of Anatomy, Kiinamyllynkatu 10, FIN-20520 Turku, Finland.
文摘Aim: The expression of the cytokines IL-2, IL-6, IL-10, IFN-γ and TNF-α and the adhesion proteins CD99 and CD106 was studied in the human testis at the protein level. Methods: The expression of the cytokines and the adhesion proteins was assessed using immunohistochemistry and immunoblotting. Results: None of the cytokines studied was present in the human testis, but CD99 and CD106 (VCAM-1) strongly were expressed in all the testes investigated. CD99 was present in the interstitial tissue of the human testis as well as in the Sertoli cells. The identity of the CD99+ interstitial cells is unclear. CD106 (VCAM-1) was present in Leydig cells as well as the basal parts of the Sertoli cells in the seminiferous tubules. In immunoblotting, CD99 was demonstrated at molecular ratios of 46-57 (kD). This is a novel isoform of the molecule. Conclusion: The human testis produces both CD99 and CD106 and as CD106 mediates cell binding to lymphocytes, it is possible that the human Leydig cells adhere to lymphocytes like the rodent Leydig cells. (Asian J Androl 2002 Dec; 4: 243-248)
基金This work was supported by an award(1R01AA021510)from the National Institutes of Health.
文摘Background and aim:a-complex protein-2(aCP2)encoded by the poly(rC)binding protein 2(PCBP2)gene is responsible for the accumulation of type I collagen in fibrotic livers.In this study,we silenced the PCBP2 gene using a small interfering RNA(siRNA)to reverse alcohol-and cytokine-induced profibrogenic effects on hepatic stellate cells(HSCs).Methods:Primary rat HSCs and the HSC-T6 cell line were used as fibrogenic models to mimic the initiation and perpetuation stages of fibrogenesis,respectively.We previously found that a PCBP2 siRNA,which efficiently silences expression of aCP2,reduces the stability of type I collagen mRNA.We investigated the effects of the PCBP2 siRNA on cell proliferation and migration.Expression of type I collagen in HSCs was analyzed by quantitative real-time PCR and western blotting.In addition,we evaluated the effects of the PCBP2 siRNA on apoptosis and the cell cycle.Results:PCBP2 siRNA reversed multiple alcohol-and cytokine-induced profibrogenic effects on primary rat HSCs and HSC-T6 cells.The PCBP2 siRNA also reversed alcohol-and cytokine-induced accumulation of type I collagen as well as cell proliferation and migration.Moreover,the combination of LY2109761,a transforming growth factor-b1 inhibitor,and the PCBP2 siRNA exerted a synergistic inhibitive effect on the accumulation of type I collagen in HSCs.Conclusions:Silencing of PCBP2 using siRNA could be a potential therapeutic strategy for alcoholic liver fibrosis.
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.
