Foot-and-mouth disease virus(FMDV)has developed various strategies to antagonize the host innate immunity.FMDV Lpro and 3Cpro interfere with type I IFNs through different mechanisms.The structural protein VP3 of FMDV ...Foot-and-mouth disease virus(FMDV)has developed various strategies to antagonize the host innate immunity.FMDV Lpro and 3Cpro interfere with type I IFNs through different mechanisms.The structural protein VP3 of FMDV degrades Janus kinase 1 to suppress IFN-γsignaling transduction.Whether non-structural proteins of FMDV are involved in restraining type II IFN signaling pathways is unknown.In this study,it was shown that FMDV replication was resistant to IFN-γtreatment after the infection was established and FMDV inhibited type II IFN induced expression of IFN-γ-stimulated genes(ISGs).We also showed for the first time that FMDV non-structural protein 3C antagonized IFN-γ-stimulated JAK-STAT signaling pathway by blocking STAT1 nuclear translocation.3C^(pro)expression significantly reduced the ISGs transcript levels and palindromic gamma-activated sequences(GAS)promoter activity,without affecting the protein level,tyrosine phosphorylation,and homodimerization of STAT1.Finally,we provided evidence that 3C protease activity played an essential role in degrading KPNA1 and thus inhibited ISGs mRNA and GAS promoter activities.Our results reveal a novel mechanism by which an FMDV non-structural protein antagonizes host type II IFN signaling.展开更多
基金the National Key Research and Development Program of China(2021YFD1800300)Natural Science Foundation of Shandong Province(ZR2021ZD08,ZR2020KC005,ZR2021MC139,ZR2020QC196)+1 种基金National Natural Science Foundation of China(32102710)the Agricultural Scientific and Technological Innovation Project of Shandong Academy of Agricultural Sciences(CXGC2023A21,CXGC2021B03,CXGC2022A17).
文摘Foot-and-mouth disease virus(FMDV)has developed various strategies to antagonize the host innate immunity.FMDV Lpro and 3Cpro interfere with type I IFNs through different mechanisms.The structural protein VP3 of FMDV degrades Janus kinase 1 to suppress IFN-γsignaling transduction.Whether non-structural proteins of FMDV are involved in restraining type II IFN signaling pathways is unknown.In this study,it was shown that FMDV replication was resistant to IFN-γtreatment after the infection was established and FMDV inhibited type II IFN induced expression of IFN-γ-stimulated genes(ISGs).We also showed for the first time that FMDV non-structural protein 3C antagonized IFN-γ-stimulated JAK-STAT signaling pathway by blocking STAT1 nuclear translocation.3C^(pro)expression significantly reduced the ISGs transcript levels and palindromic gamma-activated sequences(GAS)promoter activity,without affecting the protein level,tyrosine phosphorylation,and homodimerization of STAT1.Finally,we provided evidence that 3C protease activity played an essential role in degrading KPNA1 and thus inhibited ISGs mRNA and GAS promoter activities.Our results reveal a novel mechanism by which an FMDV non-structural protein antagonizes host type II IFN signaling.
