Lack of an appropriate small animal model remains a major hurdle for studying the immunotolerance and immunopathogenesis induced by hepatitis B virus (HBV) infection. In this study, we report a mouse model with sust...Lack of an appropriate small animal model remains a major hurdle for studying the immunotolerance and immunopathogenesis induced by hepatitis B virus (HBV) infection. In this study, we report a mouse model with sustained HBV viremia after infection with a recombinant adeno-associated virus (AAV) carrying a replicable HBV genome (AAV/ HBV). Similar to the clinical HBV carriers, the mice infected with AAV/H BV were sero-negative for antibodies against HBV surface antigen (HBsAg). Immunization with the conventional HBV vaccine in the presence of aluminum adjuvant failed to elicit an immune response against HBV in these mice. To identify a vaccine that can potentially circumvent this tolerance, the TLR9 agonist CpG was added to HBsAg as an adjuvant. Vaccination of mice with HBsAg/CpG induced not only clearance of viremia, but also strong antibody production and T-cell responses. Furthermore, both the DNA replication and protein expression of HBV were significantly reduced in the livers of AAV/H BV-infected mice. Accordingly, AAV/HBV-infected mice may be used as a robust model for investigating the underlying mechanism(s) of HBV immunotolerance and for developing novel immunotherapies to eradicate HBV infections.展开更多
The liver has particular tolerogenic properties that allow its spontaneous acceptance in some animal species.Liver structure is considered to favor a tolerogenic environment.The peripheral tolerance mechanisms also pl...The liver has particular tolerogenic properties that allow its spontaneous acceptance in some animal species.Liver structure is considered to favor a tolerogenic environment.The peripheral tolerance mechanisms also play a role in spontaneous tolerance to liver graft.In a clinical setting,the main challenge nowadays facing liver transplantation is minimization of immunosuppression with the goal of donor-specific tolerance.Mechanisms involved in tolerance to transplanted organs are complex and partly unknown.A significant mechanism in tolerance induction is chimerism.Chimerism can be induced through transplantation of allogeneic donor bone marrow/stem cells under appropriate host conditioning.This review focuses on the tolerance mechanisms in liver transplantation and highlights the role of chimerism and allogeneic bone marrow/stem cell transplantation in tolerance development.展开更多
Summary: To investigate the effect of immature dendritic cells (iDCs) on experimental autoimmune myasthenia gravis (MG), iDCs were generated in low dose of GM-CSF, and then they were pulsed with acetylcholine receptor...Summary: To investigate the effect of immature dendritic cells (iDCs) on experimental autoimmune myasthenia gravis (MG), iDCs were generated in low dose of GM-CSF, and then they were pulsed with acetylcholine receptor (AchR) and transferred to allogeneic rats. After 3 weeks, all rats were immunized with AchR and complete Freund's adjuvant (CFA) and observed for the corresponding indices of MG for 7 weeks. Our results showed that compared with mature DCs (mDCs) generated at high dose of GM-CSF plus additional stimulation by lipopolysaccharide, iDCs expressed significantly lower levels of MHC-Ⅱ, CD80 and CD86, and their ability to uptake FITC-Dextran was stronger but the ability of stimulating proliferation of allogeneic T cells were weaker. Like controls, after immunization, all rats transferred with iDCs, mDCs and AchR-pulsed mDCs showed typical symptoms in 4 to 7 weeks. The amplitude of electromyogram wave dropped obviously, the level of serum AchRab increased and neuromuscular junction showed typical damage of MG. In contrast, no conspicuous changes were noted in rats transferred with AchR-pulsed iDCs. The results suggest that iDCs could be generated by inducing bone marrow precursors in low dose of GM-CSF, AchR-pulsed iDCs could induce tolerance of EAMG. The dysfunction of DCs may play an important role in the initiation and maintenance of normal immune response in MG.展开更多
Hepatitis B virus(HBV) infection is a global public health problem,with an estimated 350 million people worldwide chronically infected and approximately 500000 who die annually from HBV-related liver diseases.Manageme...Hepatitis B virus(HBV) infection is a global public health problem,with an estimated 350 million people worldwide chronically infected and approximately 500000 who die annually from HBV-related liver diseases.Management of chronic HBV is challenging and waves of guidelines emerge every year.One of the hottest topics and a matter of debate is the management of patients in their early immunotolerant phase of infection.With the lack of evidence,dealing with this particular subset of patients creates a great conflict with opposing views.In this review,the author highlights the pros and cons of these views and proposes a reasonable solution to resolve this dilemma.展开更多
Tolerogenic dendritic cells(tol DCs)facilitate the suppression of autoimmune responses by differentiating regulatory T cells(Treg).The dysfunction of immunotolerance results in the development of autoimmune diseases,s...Tolerogenic dendritic cells(tol DCs)facilitate the suppression of autoimmune responses by differentiating regulatory T cells(Treg).The dysfunction of immunotolerance results in the development of autoimmune diseases,such as rheumatoid arthritis(RA).As multipotent progenitor cells,mesenchymal stem cells(MSCs),can regulate dendritic cells(DCs)to restore their immunosuppressive function and prevent disease development.However,the underlying mechanisms of MSCs in regulating DCs still need to be better defined.Simultaneously,the delivery system for MSCs also influences their function.Herein,MSCs are encapsulated in alginate hydrogel to improve cell survival and retention in situ,maximizing efficacy in vivo.The three-dimensional co-culture of encapsulated MSCs with DCs demonstrates that MSCs can inhibit the maturation of DCs and the secretion of pro-inflammatory cytokines.In the collagen-induced arthritis(CIA)mice model,alginate hydrogel encapsulated MSCs induce a significantly higher expression of CD39^(+)CD73^(+)on MSCs.These enzymes hydrolyze ATP to adenosine and activate A_(2A/2B)receptors on immature DCs,further promoting the phenotypic transformation of DCs to tol DCs and regulating naive T cells to Tregs.Therefore,encapsulated MSCs obviously alleviate the inflammatory response and prevent CIA progression.This finding clarifies the mechanism of MSCs-DCs crosstalk in eliciting the immunosuppression effect and provides insights into hydrogel-promoted stem cell therapy for autoimmune diseases.展开更多
Accumulating studies have demonstrated that non-coding RNAs(ncRNAs),functioning as important regulators of transcription and translation,are involved in the establishment and maintenance of pregnancy,especially the ma...Accumulating studies have demonstrated that non-coding RNAs(ncRNAs),functioning as important regulators of transcription and translation,are involved in the establishment and maintenance of pregnancy,especially the maternal immune adaptation process.The endometrial stromal cells(ESCs),trophoblast cells,and decidua immune cells that reside at the maternal-fetal interface are thought to play significant roles in normal pregnancy and pregnancy-associated diseases.Here,we reviewed the up-to-date evidence on how microRNA,long non-coding RNA,and circular RNA regulate ESCs,trophoblast cells,and immune cells and discussed the potential applications of these ncRNAs as diagnostic and therapeutic markers in pregnancy complications.展开更多
Organs such as the liver, uterus and lung possess hallmark immunotolerant features, making these organs important for sustaining self-homeostasis. These organs contain a relatively large amount of negative regulatory ...Organs such as the liver, uterus and lung possess hallmark immunotolerant features, making these organs important for sustaining self-homeostasis. These organs contain a relatively large amount of negative regulatory immune cells, which are believed to take part in the regulation of immune responses. Because natural killer cells constitute a large proportion of all lymphocytes in these organs, increasing attention has been given to the roles that these cells play in maintaining immunotolerance. Here, we review the distribution, differentiation, phenotypic features and functional features of natural killer cells in these immunotolerant organs, in addition to the influence of local microenvironments on these cells and how these factors contribute to organ-specific diseases.展开更多
The maternal immune system is vital in maintaining immunotolerance to the semiallogeneic fetus for a successful pregnancy.Although studies have shown that myeloid-derived suppressor cells(MDSCs)play an important role ...The maternal immune system is vital in maintaining immunotolerance to the semiallogeneic fetus for a successful pregnancy.Although studies have shown that myeloid-derived suppressor cells(MDSCs)play an important role in maintaining feto-maternal tolerance,little is known about the role of MDSCs in pregnancies with intrauterine growth retardation(IUGR).Here,we reported that the activation of polymorphonuclear myeloid-derived suppressor cells(PMN-MDSCs)during pregnancy was closely associated with fetal growth.In humans,class E scavenger receptor 1(SR-E1),a distinct marker for human PMN-MDSCs,was used to investigate PMN-MDSC function during pregnancy.Continuous activation of SR-E1+PMN-MDSCs was observed in all stages of pregnancy,accompanied by high cellular levels of ROS and arginase-1 activity,mediated through STAT6 signaling.However,SR-E1+PMN-MDSCs in pregnancies with IUGR showed significantly lower suppressive activity,lower arginase-1 activity and ROS levels,and decreased STAT6 phosphorylation level,which were accompanied by an increase in inflammatory factors,compared with those in normal pregnancies.Moreover,the population of SR-E1+PMN-MDSCs was negatively correlated with the adverse outcomes of newborns from pregnancies with IUGR.In mice,decreases in cell population,suppressive activity,target expression levels,and STAT6 phosphorylation levels were also observed in the pregnancies with IUGR compared with the normal pregnancies,which were rescued by the adoptive transfer of PMN-MDSCs from pregnant mice.Interestingly,the growth-promoting factors(GPFs)secreted by placental PMN-MDSCs in both humans and mice play a vital role in fetal development.These findings collectively support that PMN-MDSCs have another new role in pregnancy,which can improve adverse neonatal outcomes.展开更多
Objective To induce islet grafting tolerance by intravenous injection of anti CD 4, anti CD 8 immunotoxins and donor soluble antigen Methods Fourteen days or 7 days prior to transplantation, the immunotoxin of...Objective To induce islet grafting tolerance by intravenous injection of anti CD 4, anti CD 8 immunotoxins and donor soluble antigen Methods Fourteen days or 7 days prior to transplantation, the immunotoxin of anti CD 4, anti CD 8 200?μg respectively, and donor soluble antigen 500?μg were intravenously injected and then 500 donor islets were transplanted under the left renal subcapsular space of diabetes recipients (Sprague Dawley rats) Results The islet grafting survival time for those recipients pretreated with immunotoxin and donor soluble antigen was >60 days ( P <0 01) The immunotoxins, donor soluble antigen treatment alone might only slightly prolong the grafting survival time Conclusion The anti CD 4, anti CD 8 immunotoxins jointly used with donor soluble antigen can induce donor specific immunotolerance展开更多
文摘Lack of an appropriate small animal model remains a major hurdle for studying the immunotolerance and immunopathogenesis induced by hepatitis B virus (HBV) infection. In this study, we report a mouse model with sustained HBV viremia after infection with a recombinant adeno-associated virus (AAV) carrying a replicable HBV genome (AAV/ HBV). Similar to the clinical HBV carriers, the mice infected with AAV/H BV were sero-negative for antibodies against HBV surface antigen (HBsAg). Immunization with the conventional HBV vaccine in the presence of aluminum adjuvant failed to elicit an immune response against HBV in these mice. To identify a vaccine that can potentially circumvent this tolerance, the TLR9 agonist CpG was added to HBsAg as an adjuvant. Vaccination of mice with HBsAg/CpG induced not only clearance of viremia, but also strong antibody production and T-cell responses. Furthermore, both the DNA replication and protein expression of HBV were significantly reduced in the livers of AAV/H BV-infected mice. Accordingly, AAV/HBV-infected mice may be used as a robust model for investigating the underlying mechanism(s) of HBV immunotolerance and for developing novel immunotherapies to eradicate HBV infections.
文摘The liver has particular tolerogenic properties that allow its spontaneous acceptance in some animal species.Liver structure is considered to favor a tolerogenic environment.The peripheral tolerance mechanisms also play a role in spontaneous tolerance to liver graft.In a clinical setting,the main challenge nowadays facing liver transplantation is minimization of immunosuppression with the goal of donor-specific tolerance.Mechanisms involved in tolerance to transplanted organs are complex and partly unknown.A significant mechanism in tolerance induction is chimerism.Chimerism can be induced through transplantation of allogeneic donor bone marrow/stem cells under appropriate host conditioning.This review focuses on the tolerance mechanisms in liver transplantation and highlights the role of chimerism and allogeneic bone marrow/stem cell transplantation in tolerance development.
基金This work was supported intensively by a grant from Natural Science Foundation of Hubei proince (No.2004ADA245)
文摘Summary: To investigate the effect of immature dendritic cells (iDCs) on experimental autoimmune myasthenia gravis (MG), iDCs were generated in low dose of GM-CSF, and then they were pulsed with acetylcholine receptor (AchR) and transferred to allogeneic rats. After 3 weeks, all rats were immunized with AchR and complete Freund's adjuvant (CFA) and observed for the corresponding indices of MG for 7 weeks. Our results showed that compared with mature DCs (mDCs) generated at high dose of GM-CSF plus additional stimulation by lipopolysaccharide, iDCs expressed significantly lower levels of MHC-Ⅱ, CD80 and CD86, and their ability to uptake FITC-Dextran was stronger but the ability of stimulating proliferation of allogeneic T cells were weaker. Like controls, after immunization, all rats transferred with iDCs, mDCs and AchR-pulsed mDCs showed typical symptoms in 4 to 7 weeks. The amplitude of electromyogram wave dropped obviously, the level of serum AchRab increased and neuromuscular junction showed typical damage of MG. In contrast, no conspicuous changes were noted in rats transferred with AchR-pulsed iDCs. The results suggest that iDCs could be generated by inducing bone marrow precursors in low dose of GM-CSF, AchR-pulsed iDCs could induce tolerance of EAMG. The dysfunction of DCs may play an important role in the initiation and maintenance of normal immune response in MG.
文摘Hepatitis B virus(HBV) infection is a global public health problem,with an estimated 350 million people worldwide chronically infected and approximately 500000 who die annually from HBV-related liver diseases.Management of chronic HBV is challenging and waves of guidelines emerge every year.One of the hottest topics and a matter of debate is the management of patients in their early immunotolerant phase of infection.With the lack of evidence,dealing with this particular subset of patients creates a great conflict with opposing views.In this review,the author highlights the pros and cons of these views and proposes a reasonable solution to resolve this dilemma.
基金supported by the National Key R&D Program of China(No.2020YFA0908004)the National Natural Science Foundation of China(Nos.82293684,82293680,82273936,82273929)+1 种基金CAMS Innovation Fund for Medical Science(No.2021-I2M-1-028,2022-I2M-2-002,2022-I2M-1-014,China)Natural Science Fund for Distinguished Young Scholars of Tianjin(No.21JCJQJC00020,China)。
文摘Tolerogenic dendritic cells(tol DCs)facilitate the suppression of autoimmune responses by differentiating regulatory T cells(Treg).The dysfunction of immunotolerance results in the development of autoimmune diseases,such as rheumatoid arthritis(RA).As multipotent progenitor cells,mesenchymal stem cells(MSCs),can regulate dendritic cells(DCs)to restore their immunosuppressive function and prevent disease development.However,the underlying mechanisms of MSCs in regulating DCs still need to be better defined.Simultaneously,the delivery system for MSCs also influences their function.Herein,MSCs are encapsulated in alginate hydrogel to improve cell survival and retention in situ,maximizing efficacy in vivo.The three-dimensional co-culture of encapsulated MSCs with DCs demonstrates that MSCs can inhibit the maturation of DCs and the secretion of pro-inflammatory cytokines.In the collagen-induced arthritis(CIA)mice model,alginate hydrogel encapsulated MSCs induce a significantly higher expression of CD39^(+)CD73^(+)on MSCs.These enzymes hydrolyze ATP to adenosine and activate A_(2A/2B)receptors on immature DCs,further promoting the phenotypic transformation of DCs to tol DCs and regulating naive T cells to Tregs.Therefore,encapsulated MSCs obviously alleviate the inflammatory response and prevent CIA progression.This finding clarifies the mechanism of MSCs-DCs crosstalk in eliciting the immunosuppression effect and provides insights into hydrogel-promoted stem cell therapy for autoimmune diseases.
基金Natural Science Foundation of China(No.81873337)Natural Science Foundation of Shandong Province(No.ZR2019MH039)+2 种基金Central Government Guides Local Science and Technology Development Fund Projects of Shandong Province(No.YDZX20203700001407)Research Leader Studio Project of Jinan Science and Technology Bureau(No.2020GXRC050)Taishan Scholars(No.Tsqn201812125)
文摘Accumulating studies have demonstrated that non-coding RNAs(ncRNAs),functioning as important regulators of transcription and translation,are involved in the establishment and maintenance of pregnancy,especially the maternal immune adaptation process.The endometrial stromal cells(ESCs),trophoblast cells,and decidua immune cells that reside at the maternal-fetal interface are thought to play significant roles in normal pregnancy and pregnancy-associated diseases.Here,we reviewed the up-to-date evidence on how microRNA,long non-coding RNA,and circular RNA regulate ESCs,trophoblast cells,and immune cells and discussed the potential applications of these ncRNAs as diagnostic and therapeutic markers in pregnancy complications.
文摘Organs such as the liver, uterus and lung possess hallmark immunotolerant features, making these organs important for sustaining self-homeostasis. These organs contain a relatively large amount of negative regulatory immune cells, which are believed to take part in the regulation of immune responses. Because natural killer cells constitute a large proportion of all lymphocytes in these organs, increasing attention has been given to the roles that these cells play in maintaining immunotolerance. Here, we review the distribution, differentiation, phenotypic features and functional features of natural killer cells in these immunotolerant organs, in addition to the influence of local microenvironments on these cells and how these factors contribute to organ-specific diseases.
基金supported by grants from the following institutions:the High-level Talent Start-up Funding of Southern Medical Universitythe National Natural Science Foundation of China(grant numbers:31700061,81971420 and 81991511)+2 种基金the Guangdong Special Support Program for Youth Science and Technology Innovation Talents(grant number:2019TQ05Y585)the National Natural Science Foundation of Guangdong(grant number:2019A1515011435)the Science and Technology Program of Guangzhou(grant number:201904010073).
文摘The maternal immune system is vital in maintaining immunotolerance to the semiallogeneic fetus for a successful pregnancy.Although studies have shown that myeloid-derived suppressor cells(MDSCs)play an important role in maintaining feto-maternal tolerance,little is known about the role of MDSCs in pregnancies with intrauterine growth retardation(IUGR).Here,we reported that the activation of polymorphonuclear myeloid-derived suppressor cells(PMN-MDSCs)during pregnancy was closely associated with fetal growth.In humans,class E scavenger receptor 1(SR-E1),a distinct marker for human PMN-MDSCs,was used to investigate PMN-MDSC function during pregnancy.Continuous activation of SR-E1+PMN-MDSCs was observed in all stages of pregnancy,accompanied by high cellular levels of ROS and arginase-1 activity,mediated through STAT6 signaling.However,SR-E1+PMN-MDSCs in pregnancies with IUGR showed significantly lower suppressive activity,lower arginase-1 activity and ROS levels,and decreased STAT6 phosphorylation level,which were accompanied by an increase in inflammatory factors,compared with those in normal pregnancies.Moreover,the population of SR-E1+PMN-MDSCs was negatively correlated with the adverse outcomes of newborns from pregnancies with IUGR.In mice,decreases in cell population,suppressive activity,target expression levels,and STAT6 phosphorylation levels were also observed in the pregnancies with IUGR compared with the normal pregnancies,which were rescued by the adoptive transfer of PMN-MDSCs from pregnant mice.Interestingly,the growth-promoting factors(GPFs)secreted by placental PMN-MDSCs in both humans and mice play a vital role in fetal development.These findings collectively support that PMN-MDSCs have another new role in pregnancy,which can improve adverse neonatal outcomes.
文摘Objective To induce islet grafting tolerance by intravenous injection of anti CD 4, anti CD 8 immunotoxins and donor soluble antigen Methods Fourteen days or 7 days prior to transplantation, the immunotoxin of anti CD 4, anti CD 8 200?μg respectively, and donor soluble antigen 500?μg were intravenously injected and then 500 donor islets were transplanted under the left renal subcapsular space of diabetes recipients (Sprague Dawley rats) Results The islet grafting survival time for those recipients pretreated with immunotoxin and donor soluble antigen was >60 days ( P <0 01) The immunotoxins, donor soluble antigen treatment alone might only slightly prolong the grafting survival time Conclusion The anti CD 4, anti CD 8 immunotoxins jointly used with donor soluble antigen can induce donor specific immunotolerance