Innate immunity plays critical antiviral roles. The highly virulent avian influenza viruses (AIVs) H5N1, H7N9, and H5N6 can betterescape host innate immune responses than the less virulent seasonal H1N1 virus. Here, w...Innate immunity plays critical antiviral roles. The highly virulent avian influenza viruses (AIVs) H5N1, H7N9, and H5N6 can betterescape host innate immune responses than the less virulent seasonal H1N1 virus. Here, we report a mechanism by whichtranscriptional readthrough (TRT)-mediated suppression of innate immunity occurs post AIV infection. By using cell lines, mouselungs, and patient PBMCs, we showed that genes on the complementary strand (“trans” genes) influenced by TRT were involved inthe disruption of host antiviral responses during AIV infection. The trans-TRT enhanced viral lethality, and TRT abolishmentincreased cell viability and STAT1/2 expression. The viral NS1 protein directly bound to SSU72, and degradation of SSU72 inducedTRT. SSU72 overexpression reduced TRT and alleviated mouse lung injury. Our results suggest that AIVs infection induce TRT byreducing SSU72 expression, thereby impairing host immune responses, a molecular mechanism acting through the NS1-SSU72-trans-TRT-STAT1/2 axis. Thus, restoration of SSU72 expression might be a potential strategy for preventing AIV pandemics.展开更多
The homeostatic balance between effector T cells and regulatory T cells(Tregs)is crucial for adaptive immunity;however,epigenetic programs that inhibit phosphorylation to regulate Treg development,peripheral expressio...The homeostatic balance between effector T cells and regulatory T cells(Tregs)is crucial for adaptive immunity;however,epigenetic programs that inhibit phosphorylation to regulate Treg development,peripheral expression,and suppressive activity are elusive.Here,we found that the Ssu72 phosphatase is activated by various T-cell receptor signaling pathways,including the T-cell receptor and IL-2R pathways,and localizes at the cell membrane.Deletion of Ssu72 in T cells disrupts CD4+T-cell differentiation into Tregs in the periphery via the production of high levels of the effector cytokines IL-2 and IFNγ,which induce CD4+T-cell activation and differentiation into effector cell lineages.We also found a close correlation between downregulation of Ssu72 and severe defects in mucosal tolerance in patients.Interestingly,Ssu72 forms a complex with PLCγ1,which is an essential effector molecule for T-cell receptor signaling as well as Treg development and function.Ssu72 deficiency impairs PLCγ1 downstream signaling and results in failure of Foxp3 induction.Thus,our studies show that the Ssu72-mediated cytokine response coordinates the differentiation and function of Treg cells in the periphery.展开更多
基金This work was supported by the National Natural Science Foundation of China(NSFC)(81788101,31870163,and 32100104)the CAMS Innovation Fund for Medical Sciences(2021-I2M-1-022)+6 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(CAS)(XDB29010102)CAS Southest Asia Biodiversity Research Institute(151C53KYSB20210023)Beijing Natural Science Foundation(L192007)National Pathogen Resource Center,and State Key Laboratory Special Fund(2060204)Y.B.is supported by the NSFC Outstanding Young Scholars(31822055)Youth Innovation Promotion Association of the CAS(2017122 and Y2021034)Overseas Expertise Introduction Center for Discipline Innovation(“111 Center”)(BP0820029).
文摘Innate immunity plays critical antiviral roles. The highly virulent avian influenza viruses (AIVs) H5N1, H7N9, and H5N6 can betterescape host innate immune responses than the less virulent seasonal H1N1 virus. Here, we report a mechanism by whichtranscriptional readthrough (TRT)-mediated suppression of innate immunity occurs post AIV infection. By using cell lines, mouselungs, and patient PBMCs, we showed that genes on the complementary strand (“trans” genes) influenced by TRT were involved inthe disruption of host antiviral responses during AIV infection. The trans-TRT enhanced viral lethality, and TRT abolishmentincreased cell viability and STAT1/2 expression. The viral NS1 protein directly bound to SSU72, and degradation of SSU72 inducedTRT. SSU72 overexpression reduced TRT and alleviated mouse lung injury. Our results suggest that AIVs infection induce TRT byreducing SSU72 expression, thereby impairing host immune responses, a molecular mechanism acting through the NS1-SSU72-trans-TRT-STAT1/2 axis. Thus, restoration of SSU72 expression might be a potential strategy for preventing AIV pandemics.
基金supported by a National Research Foundation grant funded by the Korean government(MEST)(2017R1A2B3006776).
文摘The homeostatic balance between effector T cells and regulatory T cells(Tregs)is crucial for adaptive immunity;however,epigenetic programs that inhibit phosphorylation to regulate Treg development,peripheral expression,and suppressive activity are elusive.Here,we found that the Ssu72 phosphatase is activated by various T-cell receptor signaling pathways,including the T-cell receptor and IL-2R pathways,and localizes at the cell membrane.Deletion of Ssu72 in T cells disrupts CD4+T-cell differentiation into Tregs in the periphery via the production of high levels of the effector cytokines IL-2 and IFNγ,which induce CD4+T-cell activation and differentiation into effector cell lineages.We also found a close correlation between downregulation of Ssu72 and severe defects in mucosal tolerance in patients.Interestingly,Ssu72 forms a complex with PLCγ1,which is an essential effector molecule for T-cell receptor signaling as well as Treg development and function.Ssu72 deficiency impairs PLCγ1 downstream signaling and results in failure of Foxp3 induction.Thus,our studies show that the Ssu72-mediated cytokine response coordinates the differentiation and function of Treg cells in the periphery.
