Zika virus(ZIKV),a positive-sense single-stranded RNA virus,causes congenital ZIKV syndrome in children and Guillain-Barre Syndrome(GBS)in adults.ZIKV expresses nonstructural protein 5(NS5),a large protein that is ess...Zika virus(ZIKV),a positive-sense single-stranded RNA virus,causes congenital ZIKV syndrome in children and Guillain-Barre Syndrome(GBS)in adults.ZIKV expresses nonstructural protein 5(NS5),a large protein that is essential for viral replication.ZIKV NS5 confers the ability to evade interferon(IFN)signalling;however,the exact mechanism remains unclear.In this study,we employed affinity pull-down and liquid chromatography-tandem mass spectrometry(LC-MS/MS)analyses and found that splicing factor 3b subunit 3(SF3B3)is associated with the NS5-Flag pull-down complex through interaction with NS5.Functional assays showed that SF3B3 overexpression inhibited ZIKV replication by promoting IFN-stimulated gene(ISG)expression whereas silencing of SF3B3 inhibited expression of ISGs to promote ZIKV replication.GTP cyclohydrolase I(GCH1)is the first and ratelimiting enzyme in tetrahydrobiopterin(BH4)biosynthesis.NS5 upregulates the expression of GCH1 during ZIKV infection.And GCH1 marginally promoted ZIKV replication via the IFN pathway.Additionally,GCH1 expression is related to the regulation of SF3B3.Overexpression of the SF3B3 protein effectively reduced GCH1 protein levels,whereas SF3B3 knockdown increased its levels.These findings indicated that ZIKV NS5 binding protein SF3B3 contributed to the host immune response against ZIKV replication by modulating the expression of GCH1.展开更多
Variants of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)continue to emerge and evade immunity,resulting in breakthrough infections in vaccinated populations.There is an urgent need for the development o...Variants of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)continue to emerge and evade immunity,resulting in breakthrough infections in vaccinated populations.There is an urgent need for the development of vaccines with broad protective effects.In this study,we selected hotspot mutations in the receptor-binding domain(RBD)that contribute to immune escape properties and integrated them into the original RBD protein to obtain a complex RBD protein(cRBD),and we found cRBDs have broad protective effects against SARS-CoV-2 variants.Three cRBDs were designed in our study.Compared with the BA.1 RBD protein,the cRBDs induced the production of higher levels of broader-spectrum neutralizing antibodies,suggesting stronger and broader protective efficacy.In viral challenge experiments,cRBDs were more effective than BA.1 RBD in attenuating lung pathologic injury.Among the three constructs,cRBD3 showed optimal broad-spectrum and protective effects and is a promising candidate for a broad-spectrum SARS-CoV-2 vaccine.In conclusion,immunization with cRBDs triggered immunity against a wide range of variants,including those that emerged after we had completed designing the cRBDs.This study preliminarily explores and validates the feasibility of incorporating hotspot mutations that contribute to immune evasion into the RBD to expand the activity spectrum of antigen-induced antibodies.展开更多
基金supported by the National Key R&D Project of China(2021YFC230170402)CAMS Innovation Fund for Medical Sciences(2021-1-I2M-038).
文摘Zika virus(ZIKV),a positive-sense single-stranded RNA virus,causes congenital ZIKV syndrome in children and Guillain-Barre Syndrome(GBS)in adults.ZIKV expresses nonstructural protein 5(NS5),a large protein that is essential for viral replication.ZIKV NS5 confers the ability to evade interferon(IFN)signalling;however,the exact mechanism remains unclear.In this study,we employed affinity pull-down and liquid chromatography-tandem mass spectrometry(LC-MS/MS)analyses and found that splicing factor 3b subunit 3(SF3B3)is associated with the NS5-Flag pull-down complex through interaction with NS5.Functional assays showed that SF3B3 overexpression inhibited ZIKV replication by promoting IFN-stimulated gene(ISG)expression whereas silencing of SF3B3 inhibited expression of ISGs to promote ZIKV replication.GTP cyclohydrolase I(GCH1)is the first and ratelimiting enzyme in tetrahydrobiopterin(BH4)biosynthesis.NS5 upregulates the expression of GCH1 during ZIKV infection.And GCH1 marginally promoted ZIKV replication via the IFN pathway.Additionally,GCH1 expression is related to the regulation of SF3B3.Overexpression of the SF3B3 protein effectively reduced GCH1 protein levels,whereas SF3B3 knockdown increased its levels.These findings indicated that ZIKV NS5 binding protein SF3B3 contributed to the host immune response against ZIKV replication by modulating the expression of GCH1.
基金supported by the Key Project of applied basic research in Yunnan Province(202401AS070049)CAMS Innovation Fund for Medical Sciences(2021-I2M-1-038,2022-I2M-CoV19-002)+1 种基金National Key R&D Program of China(2021YFC230170402)Yunnan Key R&D Project(202103AQ100001).
文摘Variants of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)continue to emerge and evade immunity,resulting in breakthrough infections in vaccinated populations.There is an urgent need for the development of vaccines with broad protective effects.In this study,we selected hotspot mutations in the receptor-binding domain(RBD)that contribute to immune escape properties and integrated them into the original RBD protein to obtain a complex RBD protein(cRBD),and we found cRBDs have broad protective effects against SARS-CoV-2 variants.Three cRBDs were designed in our study.Compared with the BA.1 RBD protein,the cRBDs induced the production of higher levels of broader-spectrum neutralizing antibodies,suggesting stronger and broader protective efficacy.In viral challenge experiments,cRBDs were more effective than BA.1 RBD in attenuating lung pathologic injury.Among the three constructs,cRBD3 showed optimal broad-spectrum and protective effects and is a promising candidate for a broad-spectrum SARS-CoV-2 vaccine.In conclusion,immunization with cRBDs triggered immunity against a wide range of variants,including those that emerged after we had completed designing the cRBDs.This study preliminarily explores and validates the feasibility of incorporating hotspot mutations that contribute to immune evasion into the RBD to expand the activity spectrum of antigen-induced antibodies.
