It is well accepted that adaptive immunity plays a key role in the control of hepatitis B virus （HBV） infection. In contrast, the contribution of innate immunity has only received attention in recent years. Toll-lik...It is well accepted that adaptive immunity plays a key role in the control of hepatitis B virus （HBV） infection. In contrast, the contribution of innate immunity has only received attention in recent years. Toll-like receptors （TLRs） sense pathogen-associated molecule patterns and activate antiviral mechanisms, including intracellular antiviral pathways and the production of antiviral effector interferons （IFNs） and pro-inflammatory cytokines. Experimental results from in vitroand in vivo models have demonstrated that TLRs mediate the activation of cellular signaling pathways and the production of antiviral cytokines, resulting in a suppression of HBV replication. However, HBV infection is associated with downregulation of TLR expression on host cells and blockade of the activation of downstream signaling pathways. In primary HBV infection, TLRs may slow down HBV infection, but contribute only indirectly to viral clearance. Importantly, TLRs may modulate HBV-specific T- and B-cell responses in vivo, which are essential for the termination of HBV infection. Thus, TLR agonists are promising candidates to act as immunomodulators for the treatment of chronic HBV infection. Antiviral treatment may recover TLR expression and function in chronic HBV infection and may increase the efficacy of therapeutic approaches based on TLR activation. A combined therapeutic strategy with antiviral treatment and TLR activation could facilitate the restoration of HBV-specific immune responses and thereby, achieve viral clearance in chronically infected HBV patients.展开更多
Helicobacter pylori(H.pylori)infects the human stomach during infancy and develops into chronic activeinflammation.The majority of H.pylori tend to colonize within the mucous gel layer of the stomach.Thestomach lacks ...Helicobacter pylori(H.pylori)infects the human stomach during infancy and develops into chronic activeinflammation.The majority of H.pylori tend to colonize within the mucous gel layer of the stomach.Thestomach lacks its own immune function,thus innateimmunity as the first line of defense is vital for specificimmunity against H.pylori.We review recent discoveries in the pathophysiologic roles of toll-like receptors(TLRs),mainly TLR2 and TLR4,in H.pylori-induced inflammation.In addition,the TLR pathways activated byH.pylori-induced inflammation have been shown to beclosely associated not only with gastric carcinogenesis,but also with formation of the tumor microenvironmentthrough the production of pro-inflammatory cytokines,chemokines,and reactive oxygen species.Althoughthe correlation between single nucleotide polymorphisms of TLRs and gastric cancer risk remains unclear,a recent study demonstrated that STAT3-driven upregulation of TLR2 might promote gastric tumorigenesis independent of inflammation.Further research onthe regulation of TLRs in H.pylori-associated gastriccarcinogenesis will uncover diagnostic/predictive biomarkers and therapeutic targets for gastric cancer.展开更多
In recent years, the incidence of systematic severe .infection in intensive care units （ICUs） has increased significantly. Sepsis is a＂ complex, multifactorial syndrome that can develop into conditions of different...In recent years, the incidence of systematic severe .infection in intensive care units （ICUs） has increased significantly. Sepsis is a＂ complex, multifactorial syndrome that can develop into conditions of different severity, described as severe sepsis or septic shock. The immunology of severe sepsis and septic shock is poorly defined, despite many studies investigating the pathogenesis of this syndrome. With mortality rates of up to 50%, greater understanding of the interactions between host and microbe is necessary to improve patient outcome. Given the rapid progression of sepsis and immediate recruitment of the inflammatory cytokine cascade, the early innate response of the immune system to the pathogen is likely to play a critical role.展开更多
An adjuvant is usually used to enhance the immune response induced by vaccines. The choice of adjuvant or immune enhancer determines the effectiveness of the immune response. Currently, aluminium （Alum, a generic ter...An adjuvant is usually used to enhance the immune response induced by vaccines. The choice of adjuvant or immune enhancer determines the effectiveness of the immune response. Currently, aluminium （Alum, a generic term for salts of aluminium） is the only FDA-approved adjuvant. Alum predominantly induces the differentiation of Th2 cells and thus mediates an antibody immune response. Therefore, there is an urgent need for new adjuvants that enhance not only humoral but also cellular immune responses. In the present study, we demonstrates that PIKA （a stabilized dsRNA） as an adjuvant directly induces the activation and the proliferation of both B and NK cells in vitro. Injection of PIKA into mice results in the production of cytokines in vivo. In addition, the study demonstrates that PIKA promotes the maturation of bone marrow-derived dendritic cells （BMDCs） including up-regulation of the co-stimulatory molecules CD80, CD86 and CD40, and the induction of cytokines such as IL-12p70, IL-12p40 and IL-6. Importantly, after immunization of mice with HBsAg plus PIKA, the presence of PIKA enhances the titers of HBsAg-specific IgG and HBsAg-specific IFN-γ production. These results demonstrate that PIKA as an adjuvant can promote both humoral and cellular immune responses. These might have an implication in applying PIKA as an adjuvant to be used in the design and development of both therapeutic and preventive vaccines, and used in the clinical study.展开更多
AIM:To investigate the efficacy and molecularmechanisms of induced heme oxygenase(HO)-1 in protecting liver from warm ischemia/reperfusion(I/R)injury.METHODS:Partial warm ischemia was produced in the left and middle h...AIM:To investigate the efficacy and molecularmechanisms of induced heme oxygenase(HO)-1 in protecting liver from warm ischemia/reperfusion(I/R)injury.METHODS:Partial warm ischemia was produced in the left and middle hepatic lobes of SD rats for 75min,followed by 6 h of reperfusion.Rats were treated with saline,cobalt protoporphyrin(Co PP)or zinc protoporphyrin(Zn PP)at 24 h prior to the ischemia insult.Blood and samples of ischemic lobes subjected to ischemia were collected at 6 h after reperfusion.Serum transaminases level,plasma lactate dehydrogenase and myeloperoxidase activity in liver were measured.Liver histological injury and inflammatory cell infiltration were evaluated by tissue section and liver immunohistochemical analysis.We used quantitative reverse transcription polymerase chain reaction to analyze liver expression of inflammatory cytokines and chemokines.The cell lysates were subjected to immunoprecipitation with anti-Toll-IL-1R-containing adaptor inducing interferon-β(TRIF)and anti-myeloid differentiation factor 88(My D88),and then the immunoprecipitates were analyzed by SDS-PAGE and immunoblotted with the indicated antibodies.RESULTS:HO-1 protected livers from I/R injury,as evidenced by diminished liver enzymes and wellpreserved tissue architecture.In comparison with Zn PP livers 6 h after surgery,Co PP treatment livers showed a significant increase inflammatory cell infiltration of lymphocytes,plasma cells,neutrophils and macrophages.The Toll-like receptor(TLR)-4 and TANK binding kinase1 protein levels of rats treated with Co PP significantly reduced in TRIF-immunoprecipitated complex,as compared with Zn PP treatment.In addition,pretreatment with Co PP reduced the expression levels of TLR2,TLR4,IL-1R-associated kinase(IRAK)-1 and tumor necrosis factor receptor-associated factor 6 in My D88-immunoprecipitated complex.The inflammatory cytokines and chemokines m RNA expression rapidly decreased inCo PP-pretreated liver,compared with the Zn PP-treated group.However,the expression of negative regula展开更多
Mammalian Toll-like receptors （TLRs） are cellular pattern-recognizing receptors （PRRs） that recognize the molecular patterns of pathogens. After engaging the pathogenic patterned ligands, the cytosolic portion of ...Mammalian Toll-like receptors （TLRs） are cellular pattern-recognizing receptors （PRRs） that recognize the molecular patterns of pathogens. After engaging the pathogenic patterned ligands, the cytosolic portion of the TLRs in monocytes and macrophages, recruits adaptor proteins, via a receptor-driven signaling cascade, activates the transcription factor NF-kB, leading to the expression of proinflammatory cytokines, which trigger inflammation. Such rapid, innate cellular responses serve as the first line of host defense against infection by pathogens, and also stimulate the adaptive immune system to clear the invading microbes. Increasing evidence suggests that TLRs also recognize host-derived ligands, linking this group of PRRs to diseases that may not have an etiology that is associated directly with infections. Advanced glycation end products （AGEs） are nonenzymatically glycated or oxidated proteins, lipids and nucleic acids that are formed in the environment of oxidant stress and hyperglycemia. Binding of AGEs to their receptor RAGE initiates cellular signals that activate NF-kB, which results in transcription of proinflammatory factors. RAGE can also interact with other endogenous ligands generated by cell death and tissue injuries. RAGE has been implicated in chronic diseases such as diabetes, atherosclerosis, neurodisorders, cancers, as well as aging. This review discusses the possible role of RAGE as a PRR that may use signaling mechanisms parallel to TLRs＇, to solicit inflammatory reactions. Thus, in this scenario, RAGE may play a prominent role in the regulation of cellular homeostasis in the context of complex disease progression. Cellular ＆ Molecular Immunology.展开更多
Background The coordinated change of haematopoietic supporting microenvironment in bone marrow （BM） is crucial for innate immunity and inflammation. As the precursors of marrow stroma, BM derived mesenchymal stem ce...Background The coordinated change of haematopoietic supporting microenvironment in bone marrow （BM） is crucial for innate immunity and inflammation. As the precursors of marrow stroma, BM derived mesenchymal stem cells （MSCs） promote haematopoietic function, but their roles in innate immunity or inflammation have not been investigated. Here we investigated the expression of Toll like receptor 4 （TLR-4） and the effect of lipopolysaccharide （LPS） on its expression in BM MSCs in vitro. Methods MSCs were harvested from adult rat＇s BM cells by density gradient centrifugation and adhesive culture. The purity of MSCs were identified with the cell morphological feature and osteogenic capacity, the phenotypes were tested by flow cytometry. Cultured MSCs were treated by LPS （1 μg/ml, 10μg/ml or 100μg/ml） for 24 hours. The relative expression levels of TLR-4 mRNA were detected by semiquantitative reverse transcription polymerase chain reaction and costimulatory molecules （CD80, CD86 and MHC-Ⅱ） expressed on MSCs were analyzed by flow cytometry. The levels of tumor necrosis factor-α （TNF-α） in supernatants were determined by enzyme linked immunosorbent assay. Results After incubation with LPS, MSCs expressed the higher levels of TLR-4 mRNA, costimulatory molecules and TNF-α than the untreated group： LPS 10 μg/ml was the most effective （P〈0.01）; the levels of TLR-4 mRNA, costimulatory molecules and TNF-α decreased when MSCs were exposed to 100 μg/ml LPS. Except for MHC-Ⅱ and TNF-α （P〉0.05）, the levels of CD80, CD86 and TLR-4 mRNA were significantly lower than that in the treated group of 10 μg/ml （P〈0.01）. Conclusion MSCs expressed TLR-4 mRNA. LPS activated the functional expression levels of TLR-4 in MSCs although the activity may depend on the concentration of LPS.展开更多
文摘It is well accepted that adaptive immunity plays a key role in the control of hepatitis B virus （HBV） infection. In contrast, the contribution of innate immunity has only received attention in recent years. Toll-like receptors （TLRs） sense pathogen-associated molecule patterns and activate antiviral mechanisms, including intracellular antiviral pathways and the production of antiviral effector interferons （IFNs） and pro-inflammatory cytokines. Experimental results from in vitroand in vivo models have demonstrated that TLRs mediate the activation of cellular signaling pathways and the production of antiviral cytokines, resulting in a suppression of HBV replication. However, HBV infection is associated with downregulation of TLR expression on host cells and blockade of the activation of downstream signaling pathways. In primary HBV infection, TLRs may slow down HBV infection, but contribute only indirectly to viral clearance. Importantly, TLRs may modulate HBV-specific T- and B-cell responses in vivo, which are essential for the termination of HBV infection. Thus, TLR agonists are promising candidates to act as immunomodulators for the treatment of chronic HBV infection. Antiviral treatment may recover TLR expression and function in chronic HBV infection and may increase the efficacy of therapeutic approaches based on TLR activation. A combined therapeutic strategy with antiviral treatment and TLR activation could facilitate the restoration of HBV-specific immune responses and thereby, achieve viral clearance in chronically infected HBV patients.
文摘Helicobacter pylori(H.pylori)infects the human stomach during infancy and develops into chronic activeinflammation.The majority of H.pylori tend to colonize within the mucous gel layer of the stomach.Thestomach lacks its own immune function,thus innateimmunity as the first line of defense is vital for specificimmunity against H.pylori.We review recent discoveries in the pathophysiologic roles of toll-like receptors(TLRs),mainly TLR2 and TLR4,in H.pylori-induced inflammation.In addition,the TLR pathways activated byH.pylori-induced inflammation have been shown to beclosely associated not only with gastric carcinogenesis,but also with formation of the tumor microenvironmentthrough the production of pro-inflammatory cytokines,chemokines,and reactive oxygen species.Althoughthe correlation between single nucleotide polymorphisms of TLRs and gastric cancer risk remains unclear,a recent study demonstrated that STAT3-driven upregulation of TLR2 might promote gastric tumorigenesis independent of inflammation.Further research onthe regulation of TLRs in H.pylori-associated gastriccarcinogenesis will uncover diagnostic/predictive biomarkers and therapeutic targets for gastric cancer.
基金This work was supported by grants from the National Natural Science Foundation of China(No.3037134)
文摘In recent years, the incidence of systematic severe .infection in intensive care units （ICUs） has increased significantly. Sepsis is a＂ complex, multifactorial syndrome that can develop into conditions of different severity, described as severe sepsis or septic shock. The immunology of severe sepsis and septic shock is poorly defined, despite many studies investigating the pathogenesis of this syndrome. With mortality rates of up to 50%, greater understanding of the interactions between host and microbe is necessary to improve patient outcome. Given the rapid progression of sepsis and immediate recruitment of the inflammatory cytokine cascade, the early innate response of the immune system to the pathogen is likely to play a critical role.
基金supported by Guangzhou Sciences and Technology Grant-2005 Project(2005Z1-E4014)Natural Key Science Foundation of Guangdong Province of China(04105349).
文摘An adjuvant is usually used to enhance the immune response induced by vaccines. The choice of adjuvant or immune enhancer determines the effectiveness of the immune response. Currently, aluminium （Alum, a generic term for salts of aluminium） is the only FDA-approved adjuvant. Alum predominantly induces the differentiation of Th2 cells and thus mediates an antibody immune response. Therefore, there is an urgent need for new adjuvants that enhance not only humoral but also cellular immune responses. In the present study, we demonstrates that PIKA （a stabilized dsRNA） as an adjuvant directly induces the activation and the proliferation of both B and NK cells in vitro. Injection of PIKA into mice results in the production of cytokines in vivo. In addition, the study demonstrates that PIKA promotes the maturation of bone marrow-derived dendritic cells （BMDCs） including up-regulation of the co-stimulatory molecules CD80, CD86 and CD40, and the induction of cytokines such as IL-12p70, IL-12p40 and IL-6. Importantly, after immunization of mice with HBsAg plus PIKA, the presence of PIKA enhances the titers of HBsAg-specific IgG and HBsAg-specific IFN-γ production. These results demonstrate that PIKA as an adjuvant can promote both humoral and cellular immune responses. These might have an implication in applying PIKA as an adjuvant to be used in the design and development of both therapeutic and preventive vaccines, and used in the clinical study.
基金Supported by National Natural Science Foundation of China,No.81360079Yunnan Provincial Science and Technology Department and Kunming Medical University Collaborative Fund,No.2013FB142
文摘AIM:To investigate the efficacy and molecularmechanisms of induced heme oxygenase(HO)-1 in protecting liver from warm ischemia/reperfusion(I/R)injury.METHODS:Partial warm ischemia was produced in the left and middle hepatic lobes of SD rats for 75min,followed by 6 h of reperfusion.Rats were treated with saline,cobalt protoporphyrin(Co PP)or zinc protoporphyrin(Zn PP)at 24 h prior to the ischemia insult.Blood and samples of ischemic lobes subjected to ischemia were collected at 6 h after reperfusion.Serum transaminases level,plasma lactate dehydrogenase and myeloperoxidase activity in liver were measured.Liver histological injury and inflammatory cell infiltration were evaluated by tissue section and liver immunohistochemical analysis.We used quantitative reverse transcription polymerase chain reaction to analyze liver expression of inflammatory cytokines and chemokines.The cell lysates were subjected to immunoprecipitation with anti-Toll-IL-1R-containing adaptor inducing interferon-β(TRIF)and anti-myeloid differentiation factor 88(My D88),and then the immunoprecipitates were analyzed by SDS-PAGE and immunoblotted with the indicated antibodies.RESULTS:HO-1 protected livers from I/R injury,as evidenced by diminished liver enzymes and wellpreserved tissue architecture.In comparison with Zn PP livers 6 h after surgery,Co PP treatment livers showed a significant increase inflammatory cell infiltration of lymphocytes,plasma cells,neutrophils and macrophages.The Toll-like receptor(TLR)-4 and TANK binding kinase1 protein levels of rats treated with Co PP significantly reduced in TRIF-immunoprecipitated complex,as compared with Zn PP treatment.In addition,pretreatment with Co PP reduced the expression levels of TLR2,TLR4,IL-1R-associated kinase(IRAK)-1 and tumor necrosis factor receptor-associated factor 6 in My D88-immunoprecipitated complex.The inflammatory cytokines and chemokines m RNA expression rapidly decreased inCo PP-pretreated liver,compared with the Zn PP-treated group.However,the expression of negative regula
文摘Mammalian Toll-like receptors （TLRs） are cellular pattern-recognizing receptors （PRRs） that recognize the molecular patterns of pathogens. After engaging the pathogenic patterned ligands, the cytosolic portion of the TLRs in monocytes and macrophages, recruits adaptor proteins, via a receptor-driven signaling cascade, activates the transcription factor NF-kB, leading to the expression of proinflammatory cytokines, which trigger inflammation. Such rapid, innate cellular responses serve as the first line of host defense against infection by pathogens, and also stimulate the adaptive immune system to clear the invading microbes. Increasing evidence suggests that TLRs also recognize host-derived ligands, linking this group of PRRs to diseases that may not have an etiology that is associated directly with infections. Advanced glycation end products （AGEs） are nonenzymatically glycated or oxidated proteins, lipids and nucleic acids that are formed in the environment of oxidant stress and hyperglycemia. Binding of AGEs to their receptor RAGE initiates cellular signals that activate NF-kB, which results in transcription of proinflammatory factors. RAGE can also interact with other endogenous ligands generated by cell death and tissue injuries. RAGE has been implicated in chronic diseases such as diabetes, atherosclerosis, neurodisorders, cancers, as well as aging. This review discusses the possible role of RAGE as a PRR that may use signaling mechanisms parallel to TLRs＇, to solicit inflammatory reactions. Thus, in this scenario, RAGE may play a prominent role in the regulation of cellular homeostasis in the context of complex disease progression. Cellular ＆ Molecular Immunology.
文摘Background The coordinated change of haematopoietic supporting microenvironment in bone marrow （BM） is crucial for innate immunity and inflammation. As the precursors of marrow stroma, BM derived mesenchymal stem cells （MSCs） promote haematopoietic function, but their roles in innate immunity or inflammation have not been investigated. Here we investigated the expression of Toll like receptor 4 （TLR-4） and the effect of lipopolysaccharide （LPS） on its expression in BM MSCs in vitro. Methods MSCs were harvested from adult rat＇s BM cells by density gradient centrifugation and adhesive culture. The purity of MSCs were identified with the cell morphological feature and osteogenic capacity, the phenotypes were tested by flow cytometry. Cultured MSCs were treated by LPS （1 μg/ml, 10μg/ml or 100μg/ml） for 24 hours. The relative expression levels of TLR-4 mRNA were detected by semiquantitative reverse transcription polymerase chain reaction and costimulatory molecules （CD80, CD86 and MHC-Ⅱ） expressed on MSCs were analyzed by flow cytometry. The levels of tumor necrosis factor-α （TNF-α） in supernatants were determined by enzyme linked immunosorbent assay. Results After incubation with LPS, MSCs expressed the higher levels of TLR-4 mRNA, costimulatory molecules and TNF-α than the untreated group： LPS 10 μg/ml was the most effective （P〈0.01）; the levels of TLR-4 mRNA, costimulatory molecules and TNF-α decreased when MSCs were exposed to 100 μg/ml LPS. Except for MHC-Ⅱ and TNF-α （P〉0.05）, the levels of CD80, CD86 and TLR-4 mRNA were significantly lower than that in the treated group of 10 μg/ml （P〈0.01）. Conclusion MSCs expressed TLR-4 mRNA. LPS activated the functional expression levels of TLR-4 in MSCs although the activity may depend on the concentration of LPS.
