The outcome of hepatitis B viral(HBV)infection is determined by the complex interactions between replicating HBV and the immune system.While the role of the adaptive immune system in the resolution of HBV infection ha...The outcome of hepatitis B viral(HBV)infection is determined by the complex interactions between replicating HBV and the immune system.While the role of the adaptive immune system in the resolution of HBV infection has been studied extensively,the contribution of innate immune mechanisms remains to be defined.Here we examined the role of the interleukin-1 receptor/Toll-like receptor(IL-1R/TLR)signaling pathway in adaptive immune responses and viral clearance by exploring the HBV mouse model.Hydrodynamic injection with a replication-competent HBV genome was performed in wild-type mice(WT)and a panel of mouse strains lacking specific innate immunity component expression.We found higher levels of HBV protein production and replication in Tlr2^(?/?),Tlr23479^(?/?),3d/Tlr24^(?/?),Myd88/Trif^(?/?)and Irak4^(?/?)mice,which was associated with reduced HBV-specific CD8+T-cell responses in these mice.Importantly,HBV clearance was delayed for more than 2 weeks in 3d/Tlr24^(?/?),Myd88/Trif^(?/?)and Irak4^(?/?)mice compared to WT mice.HBV-specific CD8+T-cell responses were functionally impaired for producing the cytokines IFN-γ,TNF-αand IL-2 in TLR signaling-deficient mice compared to WT mice.In conclusion,the IL-1R/TLR signaling pathway might contribute to controlling HBV infection by augmenting HBV-specific CD8+T-cell responses.展开更多
BACKGROUND As human placenta-derived mesenchymal stem cells(hP-MSCs)exist in a physiologically hypoxic microenvironment,various studies have focused on the influence of hypoxia.However,the underlying mechanisms remain...BACKGROUND As human placenta-derived mesenchymal stem cells(hP-MSCs)exist in a physiologically hypoxic microenvironment,various studies have focused on the influence of hypoxia.However,the underlying mechanisms remain to be further explored.AIM The aim was to reveal the possible mechanisms by which hypoxia enhances the proliferation of hP-MSCs.METHODS A hypoxic cell incubator(2.5%O2)was used to mimic a hypoxic microenvironment.Cell counting kit-8 and 5-ethynyl-20-deoxyuridine incorporation assays were used to assay the proliferation of hP-MSCs.The cell cycle was profiled by flow cytometry.Transcriptome profiling of hP-MSCs under hypoxia was performed by RNA sequencing.CD99 mRNA expression was assayed by reverse transcription-polymerase chain reaction.Small interfering RNA-mediated hypoxia-inducible factor 1α(HIF-1α)or CD99 knockdown of hP-MSCs,luciferase reporter assays,and the ERK1/2 signaling inhibitor PD98059 were used in the mechanistic analysis.Protein expression was assayed by western blotting;immunofluorescence assays were conducted to evaluate changes in expression levels.RESULTS Hypoxia enhanced hP-MSC proliferation,increased the expression of cyclin E1,cyclin-dependent kinase 2,and cyclin A2,and decreased the expression of p21.Under hypoxia,CD99 expression was increased by HIF-1α.CD99-specific small interfering RNA or the ERK1/2 signaling inhibitor PD98059 abrogated the hypoxia-induced increase in cell proliferation.CONCLUSION Hypoxia promoted hP-MSCs proliferation in a manner dependent on CD99 regulation of the MAPK/ERK signaling pathway in vitro.展开更多
CD8＋ cytotoxic T lymphocyte （CTL） exhaustion is a chief issue for ineffective virus elimination in chronic infectious diseases. We generated novel ovalbumin （OVA）-specific OVA-Texo and HIV-specific Gag-Texo vacci...CD8＋ cytotoxic T lymphocyte （CTL） exhaustion is a chief issue for ineffective virus elimination in chronic infectious diseases. We generated novel ovalbumin （OVA）-specific OVA-Texo and HIV-specific Gag-Texo vaccines inducing therapeutic immunity. To assess their therapeutic effect in chronic infection, we developed a new chronic infection model by i.v. infecting C57BL/6 mice with the OVA-expressing adenovirus AdVova. During chronic AdVova infection, mouse CTLs were found to express the inhibitory molecules programmed cell-death protein-1 （PD-1） and lymphocyte-activation gene-3 （LAG-3） and to be functionally exhausted, showing a significant deficiency in T-cell proliferation, IFN-7 production and cytolytic effects. Naive CD8＋ T cells upregulated inhibitory PD-ligand 1 （PD-L1）, B- and T-lymphocyte attenuator and T-cell anergy-associated molecules （Grail and Itch） while down-regulating the proliferative response upon stimulation in mice with chronic infection. Remarkably, the OVA-Texo vaccine counteracted T-cell anergy and converted CTL exhaustion. The latter was associated with （i） the upregulation of a marker for CTL functionality, diacetylated histone-H3 （diAcH3）, （ii） a fourfold increase in CTLs, occurring independent of host DCs or CD4＋ T cells, and （iii） the restoration of CTL IFN-7 production and cytotoxicity. In vivo OVA-Texo-stimulated CTLs upregulated the activities of the mTORC1 pathway-related molecules Akt, S6, elF4E and T-bet, and treatment of the CTLs with an mTORC1 inhibitor, rapamycin, significantly reduced the OVA-Texo- induced increase in CTLs. Interestingly, OVA-Texo-mediated CD40L signaling played a critical role in the observed immunological effects. Importantly, the Gag-Texo vaccine induced Gag-specific therapeutic immunity in chronic infection. Therefore, this study should have a serious impact on the development of new therapeutic vaccines for human immunodeficiency virus （HIV-1） infection.展开更多
Background:Keloid is a fibrotic dermal disease characterized by an abnormal increase in fibroblast proliferation and invasion.These pathological behaviours may be related to the heterogeneity of keloid fibroblasts(KFs...Background:Keloid is a fibrotic dermal disease characterized by an abnormal increase in fibroblast proliferation and invasion.These pathological behaviours may be related to the heterogeneity of keloid fibroblasts(KFs);however,because of a lack of effective biomarkers for KFs it is difficult to study the underlying mechanism.Our previous studies revealed that the expansion of CD26+KFs was responsible for increased keloid proliferation and invasion capabilities;the intrinsic relationship and mechanism between CD26 and keloid is therefore worthy of further investigation.The aim of this studywas to explore molecular mechanisms in the process of CD26 upregulated KFs proliferation and invasion abilities,and provide more evidence for CD26 as an effective biomarker of keloid and a new clinical therapeutic target.Methods:Flow cytometry was performed to isolate CD26+/CD26−fibroblasts from KFs and normal fibroblasts.To generate stably silenced KFs for CD26 and insulin-like growth factor-1 receptor(IGF-1R),lentiviral particles encoding shRNA targeting CD26 and IGF-1R were used for transfection.Cell proliferations were analysed by cell counting kit-8 assay and 5-ethynyl-2-deoxyuridine(EdU)incorporation assay.Scratching assay and transwell assay were used to assess cell migration and invasion abilities.To further quantify the regulatory role of CD26 expression in the relevant signalling pathway,RT-qPCR,western blot,ELISA,PI3K activity assay and immunofluorescence were used.Results:Aberrant expression of CD26 in KFs was proven to be associated with increased proliferation and invasion of KFs.Furthermore,the role of the IGF-1/IGF-1 receptor axis was also studied in CD26 and was found to upregulate KF proliferation and invasion.The PI3K/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)pathway was shown to affect CD26-regulated KF proliferation and invasion by increasing phosphorylation levels of S6 kinase and 4E-binding protein.Conclusions:CD26 can be the effective biomarker for KFs,and its expression is closely related to proliferation and invasion in keloids through the IGF-1-induced PI3K/AKT/mTOR pathway.This work provides a novel perspective on the pathological mechanisms affecting KFs and therapeutic strategies against keloids.展开更多
基金grants from the Deutsche Forschungsgemeinschaft(DFG Transregio TRR60 and GRK1045/2).
文摘The outcome of hepatitis B viral(HBV)infection is determined by the complex interactions between replicating HBV and the immune system.While the role of the adaptive immune system in the resolution of HBV infection has been studied extensively,the contribution of innate immune mechanisms remains to be defined.Here we examined the role of the interleukin-1 receptor/Toll-like receptor(IL-1R/TLR)signaling pathway in adaptive immune responses and viral clearance by exploring the HBV mouse model.Hydrodynamic injection with a replication-competent HBV genome was performed in wild-type mice(WT)and a panel of mouse strains lacking specific innate immunity component expression.We found higher levels of HBV protein production and replication in Tlr2^(?/?),Tlr23479^(?/?),3d/Tlr24^(?/?),Myd88/Trif^(?/?)and Irak4^(?/?)mice,which was associated with reduced HBV-specific CD8+T-cell responses in these mice.Importantly,HBV clearance was delayed for more than 2 weeks in 3d/Tlr24^(?/?),Myd88/Trif^(?/?)and Irak4^(?/?)mice compared to WT mice.HBV-specific CD8+T-cell responses were functionally impaired for producing the cytokines IFN-γ,TNF-αand IL-2 in TLR signaling-deficient mice compared to WT mice.In conclusion,the IL-1R/TLR signaling pathway might contribute to controlling HBV infection by augmenting HBV-specific CD8+T-cell responses.
基金Stem Cell and Translational Research from the National Key Research and Development Program of China,No.2020YFA0113003National Natural Science Foundation of China, No. 81971756.
文摘BACKGROUND As human placenta-derived mesenchymal stem cells(hP-MSCs)exist in a physiologically hypoxic microenvironment,various studies have focused on the influence of hypoxia.However,the underlying mechanisms remain to be further explored.AIM The aim was to reveal the possible mechanisms by which hypoxia enhances the proliferation of hP-MSCs.METHODS A hypoxic cell incubator(2.5%O2)was used to mimic a hypoxic microenvironment.Cell counting kit-8 and 5-ethynyl-20-deoxyuridine incorporation assays were used to assay the proliferation of hP-MSCs.The cell cycle was profiled by flow cytometry.Transcriptome profiling of hP-MSCs under hypoxia was performed by RNA sequencing.CD99 mRNA expression was assayed by reverse transcription-polymerase chain reaction.Small interfering RNA-mediated hypoxia-inducible factor 1α(HIF-1α)or CD99 knockdown of hP-MSCs,luciferase reporter assays,and the ERK1/2 signaling inhibitor PD98059 were used in the mechanistic analysis.Protein expression was assayed by western blotting;immunofluorescence assays were conducted to evaluate changes in expression levels.RESULTS Hypoxia enhanced hP-MSC proliferation,increased the expression of cyclin E1,cyclin-dependent kinase 2,and cyclin A2,and decreased the expression of p21.Under hypoxia,CD99 expression was increased by HIF-1α.CD99-specific small interfering RNA or the ERK1/2 signaling inhibitor PD98059 abrogated the hypoxia-induced increase in cell proliferation.CONCLUSION Hypoxia promoted hP-MSCs proliferation in a manner dependent on CD99 regulation of the MAPK/ERK signaling pathway in vitro.
文摘CD8＋ cytotoxic T lymphocyte （CTL） exhaustion is a chief issue for ineffective virus elimination in chronic infectious diseases. We generated novel ovalbumin （OVA）-specific OVA-Texo and HIV-specific Gag-Texo vaccines inducing therapeutic immunity. To assess their therapeutic effect in chronic infection, we developed a new chronic infection model by i.v. infecting C57BL/6 mice with the OVA-expressing adenovirus AdVova. During chronic AdVova infection, mouse CTLs were found to express the inhibitory molecules programmed cell-death protein-1 （PD-1） and lymphocyte-activation gene-3 （LAG-3） and to be functionally exhausted, showing a significant deficiency in T-cell proliferation, IFN-7 production and cytolytic effects. Naive CD8＋ T cells upregulated inhibitory PD-ligand 1 （PD-L1）, B- and T-lymphocyte attenuator and T-cell anergy-associated molecules （Grail and Itch） while down-regulating the proliferative response upon stimulation in mice with chronic infection. Remarkably, the OVA-Texo vaccine counteracted T-cell anergy and converted CTL exhaustion. The latter was associated with （i） the upregulation of a marker for CTL functionality, diacetylated histone-H3 （diAcH3）, （ii） a fourfold increase in CTLs, occurring independent of host DCs or CD4＋ T cells, and （iii） the restoration of CTL IFN-7 production and cytotoxicity. In vivo OVA-Texo-stimulated CTLs upregulated the activities of the mTORC1 pathway-related molecules Akt, S6, elF4E and T-bet, and treatment of the CTLs with an mTORC1 inhibitor, rapamycin, significantly reduced the OVA-Texo- induced increase in CTLs. Interestingly, OVA-Texo-mediated CD40L signaling played a critical role in the observed immunological effects. Importantly, the Gag-Texo vaccine induced Gag-specific therapeutic immunity in chronic infection. Therefore, this study should have a serious impact on the development of new therapeutic vaccines for human immunodeficiency virus （HIV-1） infection.
基金supported by the National Natural Science Foundation of China(81772098,81801917,81801918)the Outstanding Professional and Technical Leader Program of the Shanghai Municipal Science and Technology Commission(18XD1423700)+3 种基金the Clinical Multi-Disciplinary Team Research Program of 9th People’s Hospital,Shanghai Jiao Tong University School of Medicine(2017-1-007)the Clinical Research Program of 9th People’s Hospital,Shanghai Jiao Tong University School of Medicine(JYLJ027)the Shanghai Municipal Education Commission Gaofeng Clinical Medicine Grant Support(20152227)the project of Science and Technology Commission of Shanghai Municipality(17411952800,18441904500).
文摘Background:Keloid is a fibrotic dermal disease characterized by an abnormal increase in fibroblast proliferation and invasion.These pathological behaviours may be related to the heterogeneity of keloid fibroblasts(KFs);however,because of a lack of effective biomarkers for KFs it is difficult to study the underlying mechanism.Our previous studies revealed that the expansion of CD26+KFs was responsible for increased keloid proliferation and invasion capabilities;the intrinsic relationship and mechanism between CD26 and keloid is therefore worthy of further investigation.The aim of this studywas to explore molecular mechanisms in the process of CD26 upregulated KFs proliferation and invasion abilities,and provide more evidence for CD26 as an effective biomarker of keloid and a new clinical therapeutic target.Methods:Flow cytometry was performed to isolate CD26+/CD26−fibroblasts from KFs and normal fibroblasts.To generate stably silenced KFs for CD26 and insulin-like growth factor-1 receptor(IGF-1R),lentiviral particles encoding shRNA targeting CD26 and IGF-1R were used for transfection.Cell proliferations were analysed by cell counting kit-8 assay and 5-ethynyl-2-deoxyuridine(EdU)incorporation assay.Scratching assay and transwell assay were used to assess cell migration and invasion abilities.To further quantify the regulatory role of CD26 expression in the relevant signalling pathway,RT-qPCR,western blot,ELISA,PI3K activity assay and immunofluorescence were used.Results:Aberrant expression of CD26 in KFs was proven to be associated with increased proliferation and invasion of KFs.Furthermore,the role of the IGF-1/IGF-1 receptor axis was also studied in CD26 and was found to upregulate KF proliferation and invasion.The PI3K/protein kinase B(AKT)/mammalian target of rapamycin(mTOR)pathway was shown to affect CD26-regulated KF proliferation and invasion by increasing phosphorylation levels of S6 kinase and 4E-binding protein.Conclusions:CD26 can be the effective biomarker for KFs,and its expression is closely related to proliferation and invasion in keloids through the IGF-1-induced PI3K/AKT/mTOR pathway.This work provides a novel perspective on the pathological mechanisms affecting KFs and therapeutic strategies against keloids.
