[Objective] This study aimed to establish an in vitro culture model for porcine peripheral blood monocyte-derived dendritic cells （MoDCs）. [Method] Fresh peripheral blood mononuclear cells （PBMCs） were separated f...[Objective] This study aimed to establish an in vitro culture model for porcine peripheral blood monocyte-derived dendritic cells （MoDCs）. [Method] Fresh peripheral blood mononuclear cells （PBMCs） were separated from pig, and precursor dendritic cells were obtained by adherence method. The dendritic cells were treated by recombinant porcine granulocyte-monocyte colony stimulating factor （rpGM-CSF） and recombinant porcine interleukin-4 （rplL-4） together, and lipopolysaccharide （LPS） respectively. The cells in different time periods were collected. The morphology of the collected cells was observed by scanning electron microscopy; the expression of surface molecules and phagocytic ability to FITC-dextran were detected by flow cy- tometry; and the stimulating ability for allogeneic T cells was detected by mixed lymphocyte reaction. [Result] The DCs suffering maturation induction in vitro showed typical dendritic morphology; compared with those of DCs untreated by LPS, the cell surface expression of CDla, CD80, CD86, SLAII and CD172a of DCs treated by LPS was significantly increased, the phagocytic ability was reduced slightly, and the stimulating ability for allogeneic T cells was enhanced to some extent. [Conclusion] An in vitro culture method was successfully established for porcine MoDCs in this study, laying a foundation for further study on the role of porcine MoDCs in immunoregulation and anti-virus infection.展开更多
[Objective] This study aimed to investigate the changes of the transcriptional levels of molecules associated with endogenous antigen processing and presenta- tion in porcine skin-derived dendritic cells infected with...[Objective] This study aimed to investigate the changes of the transcriptional levels of molecules associated with endogenous antigen processing and presenta- tion in porcine skin-derived dendritic cells infected with PCV2 in vivo. [Method] Healthy 40-day-old Landrace piglets were infected with porcine circovirus type 2 （PCV2） and euthanized on the 34, 7rd, 14th, 21st and 35th d post inoculation （DPI）. The porcine skin-derived dendritic cells （DCs） were collected to analyze the transcrip- tional levels of molecules （LMP7, UBP, MHC-I, calreticulin） associated with endogenous antigen processing and presentation by using real-time fluorescent quantitative PCR （real-time FQ-PCR）. [Result] The results showed that the level of LMP7 mR- NAs was reduced significantly on the 3DPI （P〈0.05）; the level of UBP mRNAs was consistently up-regulated, which increased significantly on the 21DPI and 35DPI （P〈 0.05）; the level of MHC-I mRNAs was significantly down-regulated on the 7DPI （P〈 0.05）; the level of calreticulin mRNAs was up-regulated slightly without significant dif- ference. [Conclusion] PCV2 can inhibit the endogenous antigen processing and presentation ability of porcine skin-derived DCs at early stages of infection.展开更多
Porcine reproductive and respiratory syndrome(PRRS) is one of the most important diseases of swine industry. The causal agent, PRRS-virus(PRRSV), is able to evade the host immune response and survive in the organism c...Porcine reproductive and respiratory syndrome(PRRS) is one of the most important diseases of swine industry. The causal agent, PRRS-virus(PRRSV), is able to evade the host immune response and survive in the organism causing transient infections. Despite all scientific efforts, there are still some gaps in the knowledge of the pathogenesis of this disease. Antigen presenting cells(APCs), as initiators of the immune response, are located in the first line of defense against microorganisms, and are responsible for antigen recognition, processing and presentation. Dendritic cells(DCs) are the main type of APC involved in antigen presentation and they are susceptible to PRRSV infection. Thus, PRRSV replication in DCs may trigger off different mechanisms to impair the onset of a host effective immune response against the virus. On the one side, PRRSV may impair the basic functions of DCs by regulating the expression of major histocompatibility complex class Ⅱ and CD80/86. Other strategy followed by the virus is the induction of cell death of APCs by apoptosis, necrosis or both of them. The impairment and/or cell death ofAPCs could lead to a failure in the onset of an efficient immune response, as long as cells could not properly activate T cells. Future aspects to take into account are also discussed in this review.展开更多
Accumulating evidence suggests that the Thl immune .response induced by various antigens such as oxidized low density lipoprotein （ox-LDL） and heat shock proteins （HSPs） play a key role in the process of atheroscl...Accumulating evidence suggests that the Thl immune .response induced by various antigens such as oxidized low density lipoprotein （ox-LDL） and heat shock proteins （HSPs） play a key role in the process of atherosclerosis.1Dendritic cells （DCs） are the most potent antigen-presenting cells （APCs） in the body with the unique ability to initiate a primary immune response to certain antigens by the activation of ＂naive＂ T cells.2 The maturation of DC with the upregulation of costimulatory molecules such as CD83, CD40, CD86, and major histocompatibility complex （MHC） class molecules such as human leukocyte antigen （HLA）-DR, is required for DC to activate T cells. Pathologic studies have shown that immature DCs are present in normal arterial while abundant mature DCs clustered with T cells could be visualized in atherogenic vessels suggesting that DC 3 maturation is linked to the progression of atherosclerosls. Peroxisome proliferator-activated receptors （PPARs） a, one member of the family of PPARs, was found to have favorable effects on slowing the progression of atherosclerosis and reducing the risk of coronary heart disease in high-risk patients independent from their metabolism effects.4＇5 Furthermore, PPAR-α is also expressed on monocytes and monocyte-derived DCs.6 The effects of PPAR-α on DCs maturation and immune function remain unknown now, we therefore observed the effects of fenofibrate, a PPAR-α agonist, on the maturation and immune function of oxidized LDL-treated DCs in this study.展开更多
Dendritic cells （DCs） play a pivotal role in linking the innate immunity and acquired immunity in responses to pathogen. Non-human primates such as Chinese Rhesus Macaque （CRM） are the favorable models for preclin...Dendritic cells （DCs） play a pivotal role in linking the innate immunity and acquired immunity in responses to pathogen. Non-human primates such as Chinese Rhesus Macaque （CRM） are the favorable models for preclinical study of potential therapeutic drugs, vaccines and mechanisms of human diseases. However, the phenotypical characterization of monocyte-derived dendritic cells （MDDCs） from CRM has not been elucidated. Monocytes from CRM were cultured with GM-CSF and IL-4 in RPMI-1640. Six days later, these cells were differentiated with typical dendritical morphology. CDllc and DC-SIGN were highly expressed. The immature MDDCs expressed the low levels of CD25, CD80, CD83, moderate CD40, CD86, and high MHC. After stimulation, the mature MDDCs increased expression of mature molecules CD25 and CD83, co-stimulatory molecules such as CD80, CD86 and CD40, and kept a high level of MHC. The capacity of endocytosis decreased with maturation. The mature MDDCs have strong ability of inducing allogeneic T cell proliferation and producing IL-12. In conclusion, we have characterized the phenotype and ultimate function of MDDCs from CRM for the first time.展开更多
Early and strong interferon type I (IFN-I) responses are usually associated with mild COVID-19 disease, whereas persistent orunregulated proinflammatory cytokine responses are associated with severe disease outcomes. ...Early and strong interferon type I (IFN-I) responses are usually associated with mild COVID-19 disease, whereas persistent orunregulated proinflammatory cytokine responses are associated with severe disease outcomes. Previous work suggested thatmonocyte-derived macrophages (MDMs) are resistant and unresponsive to SARS-CoV-2 infection. Here, we demonstrate that uponphagocytosis of SARS-CoV-2-infected cells, MDMs are activated and secrete IL-6 and TNF. Importantly, activated MDMs in turnmediate strong activation of plasmacytoid dendritic cells (pDCs), leading to the secretion of high levels of IFN-α and TNF.Furthermore, pDC activation promoted IL-6 production by MDMs. This kind of pDC activation was dependent on direct integrinmediated cell‒cell contacts and involved stimulation of the TLR7 and STING signaling pathways. Overall, the present studydescribes a novel and potent pathway of pDC activation that is linked to the macrophage-mediated clearance of infected cells.These findings suggest that a high infection rate by SARS-CoV-2 may lead to exaggerated cytokine responses, which maycontribute to tissue damage and severe disease.展开更多
Epigenetic regulation has been attracting increasing attention due to its role in cell differentiation and behaviors.However,the epigenetic mechanisms that regulate human dendritic cell(DC)differentiation and developm...Epigenetic regulation has been attracting increasing attention due to its role in cell differentiation and behaviors.However,the epigenetic mechanisms that regulate human dendritic cell(DC)differentiation and development remain poorly understood.Our previous studies show that extracellular heat shock protein 70-like protein(HSP70L1)is a potent adjuvant of Th1 responses via stimulating DCs when released from cells;however,the role of intracellular HSP70L1 in DC differentiation and maturation remains unknown.Herein,we demonstrate that intracellular HSP70L1 inhibits human DC maturation by suppressing MHC and costimulatory molecule expression,in contrast to the adjuvant activity of extracellular HSP70L1.The stability of intracellular HSP70L1 is dependent on DNAJC2,a known epigenetic regulator.Mechanistically,intracellular HSP70L1 inhibits the recruitment of Ash1l to and maintains the repressive H3K27me3 and H2AK119Ub1 modifications on the promoter regions of costimulatory,MHC and STAT3 genes.Thus,intracellular HSP70L1 is an inhibitor of human DC maturation.Our results provide new insights into the epigenetic regulation of cell development by intracellular HSP70L1.展开更多
基金Supported by Fundamental and Advanced Research Projects of Henan Province(152300410076,2015-2017)Key Science and Technology Program of Henan Province(152102110048,2015-2017)~~
文摘[Objective] This study aimed to establish an in vitro culture model for porcine peripheral blood monocyte-derived dendritic cells （MoDCs）. [Method] Fresh peripheral blood mononuclear cells （PBMCs） were separated from pig, and precursor dendritic cells were obtained by adherence method. The dendritic cells were treated by recombinant porcine granulocyte-monocyte colony stimulating factor （rpGM-CSF） and recombinant porcine interleukin-4 （rplL-4） together, and lipopolysaccharide （LPS） respectively. The cells in different time periods were collected. The morphology of the collected cells was observed by scanning electron microscopy; the expression of surface molecules and phagocytic ability to FITC-dextran were detected by flow cy- tometry; and the stimulating ability for allogeneic T cells was detected by mixed lymphocyte reaction. [Result] The DCs suffering maturation induction in vitro showed typical dendritic morphology; compared with those of DCs untreated by LPS, the cell surface expression of CDla, CD80, CD86, SLAII and CD172a of DCs treated by LPS was significantly increased, the phagocytic ability was reduced slightly, and the stimulating ability for allogeneic T cells was enhanced to some extent. [Conclusion] An in vitro culture method was successfully established for porcine MoDCs in this study, laying a foundation for further study on the role of porcine MoDCs in immunoregulation and anti-virus infection.
基金Supported by Natural Science Foundation of Beijing "Effect of porcine skin-derived dendritic cells on PCV infection" (6062006)Beijing Organization Department Project"Influence of PCV infection on bone marrow cell differentiation" (20061D0502100282)~~
文摘[Objective] This study aimed to investigate the changes of the transcriptional levels of molecules associated with endogenous antigen processing and presenta- tion in porcine skin-derived dendritic cells infected with PCV2 in vivo. [Method] Healthy 40-day-old Landrace piglets were infected with porcine circovirus type 2 （PCV2） and euthanized on the 34, 7rd, 14th, 21st and 35th d post inoculation （DPI）. The porcine skin-derived dendritic cells （DCs） were collected to analyze the transcrip- tional levels of molecules （LMP7, UBP, MHC-I, calreticulin） associated with endogenous antigen processing and presentation by using real-time fluorescent quantitative PCR （real-time FQ-PCR）. [Result] The results showed that the level of LMP7 mR- NAs was reduced significantly on the 3DPI （P〈0.05）; the level of UBP mRNAs was consistently up-regulated, which increased significantly on the 21DPI and 35DPI （P〈 0.05）; the level of MHC-I mRNAs was significantly down-regulated on the 7DPI （P〈 0.05）; the level of calreticulin mRNAs was up-regulated slightly without significant dif- ference. [Conclusion] PCV2 can inhibit the endogenous antigen processing and presentation ability of porcine skin-derived DCs at early stages of infection.
基金Supported by The Spanish Ministry of Education and Science,No.AGL2009-12438/GAN
文摘Porcine reproductive and respiratory syndrome(PRRS) is one of the most important diseases of swine industry. The causal agent, PRRS-virus(PRRSV), is able to evade the host immune response and survive in the organism causing transient infections. Despite all scientific efforts, there are still some gaps in the knowledge of the pathogenesis of this disease. Antigen presenting cells(APCs), as initiators of the immune response, are located in the first line of defense against microorganisms, and are responsible for antigen recognition, processing and presentation. Dendritic cells(DCs) are the main type of APC involved in antigen presentation and they are susceptible to PRRSV infection. Thus, PRRSV replication in DCs may trigger off different mechanisms to impair the onset of a host effective immune response against the virus. On the one side, PRRSV may impair the basic functions of DCs by regulating the expression of major histocompatibility complex class Ⅱ and CD80/86. Other strategy followed by the virus is the induction of cell death of APCs by apoptosis, necrosis or both of them. The impairment and/or cell death ofAPCs could lead to a failure in the onset of an efficient immune response, as long as cells could not properly activate T cells. Future aspects to take into account are also discussed in this review.
文摘Accumulating evidence suggests that the Thl immune .response induced by various antigens such as oxidized low density lipoprotein （ox-LDL） and heat shock proteins （HSPs） play a key role in the process of atherosclerosis.1Dendritic cells （DCs） are the most potent antigen-presenting cells （APCs） in the body with the unique ability to initiate a primary immune response to certain antigens by the activation of ＂naive＂ T cells.2 The maturation of DC with the upregulation of costimulatory molecules such as CD83, CD40, CD86, and major histocompatibility complex （MHC） class molecules such as human leukocyte antigen （HLA）-DR, is required for DC to activate T cells. Pathologic studies have shown that immature DCs are present in normal arterial while abundant mature DCs clustered with T cells could be visualized in atherogenic vessels suggesting that DC 3 maturation is linked to the progression of atherosclerosls. Peroxisome proliferator-activated receptors （PPARs） a, one member of the family of PPARs, was found to have favorable effects on slowing the progression of atherosclerosis and reducing the risk of coronary heart disease in high-risk patients independent from their metabolism effects.4＇5 Furthermore, PPAR-α is also expressed on monocytes and monocyte-derived DCs.6 The effects of PPAR-α on DCs maturation and immune function remain unknown now, we therefore observed the effects of fenofibrate, a PPAR-α agonist, on the maturation and immune function of oxidized LDL-treated DCs in this study.
文摘Dendritic cells （DCs） play a pivotal role in linking the innate immunity and acquired immunity in responses to pathogen. Non-human primates such as Chinese Rhesus Macaque （CRM） are the favorable models for preclinical study of potential therapeutic drugs, vaccines and mechanisms of human diseases. However, the phenotypical characterization of monocyte-derived dendritic cells （MDDCs） from CRM has not been elucidated. Monocytes from CRM were cultured with GM-CSF and IL-4 in RPMI-1640. Six days later, these cells were differentiated with typical dendritical morphology. CDllc and DC-SIGN were highly expressed. The immature MDDCs expressed the low levels of CD25, CD80, CD83, moderate CD40, CD86, and high MHC. After stimulation, the mature MDDCs increased expression of mature molecules CD25 and CD83, co-stimulatory molecules such as CD80, CD86 and CD40, and kept a high level of MHC. The capacity of endocytosis decreased with maturation. The mature MDDCs have strong ability of inducing allogeneic T cell proliferation and producing IL-12. In conclusion, we have characterized the phenotype and ultimate function of MDDCs from CRM for the first time.
文摘Early and strong interferon type I (IFN-I) responses are usually associated with mild COVID-19 disease, whereas persistent orunregulated proinflammatory cytokine responses are associated with severe disease outcomes. Previous work suggested thatmonocyte-derived macrophages (MDMs) are resistant and unresponsive to SARS-CoV-2 infection. Here, we demonstrate that uponphagocytosis of SARS-CoV-2-infected cells, MDMs are activated and secrete IL-6 and TNF. Importantly, activated MDMs in turnmediate strong activation of plasmacytoid dendritic cells (pDCs), leading to the secretion of high levels of IFN-α and TNF.Furthermore, pDC activation promoted IL-6 production by MDMs. This kind of pDC activation was dependent on direct integrinmediated cell‒cell contacts and involved stimulation of the TLR7 and STING signaling pathways. Overall, the present studydescribes a novel and potent pathway of pDC activation that is linked to the macrophage-mediated clearance of infected cells.These findings suggest that a high infection rate by SARS-CoV-2 may lead to exaggerated cytokine responses, which maycontribute to tissue damage and severe disease.
基金We thank Yanfeng Li for the technical assistance.This work was supported by grants from the National Key R&D Program of China(2018YFA0507401)the National Natural Science Foundation of China(31670875 and 31470858).
文摘Epigenetic regulation has been attracting increasing attention due to its role in cell differentiation and behaviors.However,the epigenetic mechanisms that regulate human dendritic cell(DC)differentiation and development remain poorly understood.Our previous studies show that extracellular heat shock protein 70-like protein(HSP70L1)is a potent adjuvant of Th1 responses via stimulating DCs when released from cells;however,the role of intracellular HSP70L1 in DC differentiation and maturation remains unknown.Herein,we demonstrate that intracellular HSP70L1 inhibits human DC maturation by suppressing MHC and costimulatory molecule expression,in contrast to the adjuvant activity of extracellular HSP70L1.The stability of intracellular HSP70L1 is dependent on DNAJC2,a known epigenetic regulator.Mechanistically,intracellular HSP70L1 inhibits the recruitment of Ash1l to and maintains the repressive H3K27me3 and H2AK119Ub1 modifications on the promoter regions of costimulatory,MHC and STAT3 genes.Thus,intracellular HSP70L1 is an inhibitor of human DC maturation.Our results provide new insights into the epigenetic regulation of cell development by intracellular HSP70L1.
