AIM: To elucidate the molecular mechanisms leading to development of functionally impaired dendritic cells(DCs) in chronic hepatitis C(CHC) patients infected with genotype 3 virus.METHODS: This prospective study was c...AIM: To elucidate the molecular mechanisms leading to development of functionally impaired dendritic cells(DCs) in chronic hepatitis C(CHC) patients infected with genotype 3 virus.METHODS: This prospective study was conducted on the cohorts of CHC individuals identified as responders or non-responders to antiviral therapy. Myeloid DCs were isolated from the peripheral blood of each subject using CD1c(BDCA1)+ DC isolation Kit. Monocytes from healthy donor were cultured with DC growth factors such as IL-4 and GM-CSF either in the presence or absence of hepatitis C virus(HCV) viral proteins followed by LPS stimulation. Phenotyping was done by flowcytometry and gene expression profiling was evaluated by real-time PCR.RESULTS: Non-responders [sustained virological response(SVR)-ve] to conventional antiviral therapy had significantly higher expression of genes associated with interferon responsive element such as IDO1 and PD-L1(6-fold) and negative regulators of JAK-STAT pathway such as SOCS(6-fold) as compared to responders(SVR+ve) to antiviral therapy. The downregulated genes in non-responders included factors involved in antigen processing and presentation mainly belonging to major histocompatibility complex(MHC) Class-Ⅱ family as HLA-DP, HLA-DQ(2-fold) and superoxide dismutase(2-fold). Cells grown in the presence of HCV viral proteins had genes downregulated for factors involved in innate response, interferon signaling, DC maturation and co-stimulatory signaling to T-cells, while the genes for cytokine signaling and Toll-like receptors(4-fold) were upregulated as compared to cells grown in absence of viral proteins.CONCLUSION: Underexpressed MHC class-Ⅱ genes and upregulated negative regulators in non-responders indicate diminished capacity to present antigen and may constitute mechanism of functionally defective state of DCs.展开更多
The major histocompatibility complex(MHC) is the exclusive chaperone that presents intracellular antigens,either self or foreign to T cells.Interestingly,aberrant expression of MHC molecules has been reported in vario...The major histocompatibility complex(MHC) is the exclusive chaperone that presents intracellular antigens,either self or foreign to T cells.Interestingly,aberrant expression of MHC molecules has been reported in various autoimmune target tissues such as thyroid follicular cells in Grave's disease.Herein,we review the discovery of an unexpected effect of cytosolic doublestranded DNA(ds DNA),despite its origins,to induce antigen processing and presenting genes,including MHC molecules,in non-immune cells.Moreover,we highlight several recent studies that suggest cell injury endows thyroid epithelial cells with a phenotype of mature antigen presenting cells by inducing multiple antigen processing and presenting genes via releasing genomic DNA fragments into the cytosol.We discuss the possibility that such cytosolic ds DNA,in naked form without binding to histone proteins,might be involved in the development of cell damage-triggered autoimmune responses.We also discuss the possible molecular mechanism by which cytosolic ds DNA can induce MHC molecules.It is reasonable to speculate that cytosolic ds DNA-induced MHC class Ⅰ is partially due to an autocrine/paracrine effect of type Ⅰ interferon(IFN).While the mechanism of cytosolic ds DNA-induced MHC class Ⅱ expression appears,at least partially,distinct from that mediated by IFN-γ.Further in-depth are required to clarify this picture.展开更多
通过对牙鲆(Paralichthys olivaceus)MHC II B基因内含子1和外显子2直接测序的方法,从83个抗病牙鲆个体中共得到了85个等位基因,其中76个为新发现的等位基因。在扩增得到的263bp的外显子2中,共发现了60个多态性位点,其中33个是新发现的...通过对牙鲆(Paralichthys olivaceus)MHC II B基因内含子1和外显子2直接测序的方法,从83个抗病牙鲆个体中共得到了85个等位基因,其中76个为新发现的等位基因。在扩增得到的263bp的外显子2中,共发现了60个多态性位点,其中33个是新发现的。不同的等位基因均以较低的频率出现,基因频率范围从0.006到0.069,基因型频率范围从0.012到0.169。通过序列分析,共发现了6种内含子1,其中4种是新发现的。内含子1中均包含了一个12bp的重复单元,其3'端含有一个富含CT/GT的区域。牙鲆MHC II B基因的高多态型和低频率揭示了牙鲆群体MHC基因资源的丰富性,为选择育种提供了可能。展开更多
基金Supported by Council of Scientific and Industrial Research,No.27(0262)12/EMR-II
文摘AIM: To elucidate the molecular mechanisms leading to development of functionally impaired dendritic cells(DCs) in chronic hepatitis C(CHC) patients infected with genotype 3 virus.METHODS: This prospective study was conducted on the cohorts of CHC individuals identified as responders or non-responders to antiviral therapy. Myeloid DCs were isolated from the peripheral blood of each subject using CD1c(BDCA1)+ DC isolation Kit. Monocytes from healthy donor were cultured with DC growth factors such as IL-4 and GM-CSF either in the presence or absence of hepatitis C virus(HCV) viral proteins followed by LPS stimulation. Phenotyping was done by flowcytometry and gene expression profiling was evaluated by real-time PCR.RESULTS: Non-responders [sustained virological response(SVR)-ve] to conventional antiviral therapy had significantly higher expression of genes associated with interferon responsive element such as IDO1 and PD-L1(6-fold) and negative regulators of JAK-STAT pathway such as SOCS(6-fold) as compared to responders(SVR+ve) to antiviral therapy. The downregulated genes in non-responders included factors involved in antigen processing and presentation mainly belonging to major histocompatibility complex(MHC) Class-Ⅱ family as HLA-DP, HLA-DQ(2-fold) and superoxide dismutase(2-fold). Cells grown in the presence of HCV viral proteins had genes downregulated for factors involved in innate response, interferon signaling, DC maturation and co-stimulatory signaling to T-cells, while the genes for cytokine signaling and Toll-like receptors(4-fold) were upregulated as compared to cells grown in absence of viral proteins.CONCLUSION: Underexpressed MHC class-Ⅱ genes and upregulated negative regulators in non-responders indicate diminished capacity to present antigen and may constitute mechanism of functionally defective state of DCs.
基金Scientific Research from the Japan Society for the Promotion of Science to Suzuki K,No.15K09444
文摘The major histocompatibility complex(MHC) is the exclusive chaperone that presents intracellular antigens,either self or foreign to T cells.Interestingly,aberrant expression of MHC molecules has been reported in various autoimmune target tissues such as thyroid follicular cells in Grave's disease.Herein,we review the discovery of an unexpected effect of cytosolic doublestranded DNA(ds DNA),despite its origins,to induce antigen processing and presenting genes,including MHC molecules,in non-immune cells.Moreover,we highlight several recent studies that suggest cell injury endows thyroid epithelial cells with a phenotype of mature antigen presenting cells by inducing multiple antigen processing and presenting genes via releasing genomic DNA fragments into the cytosol.We discuss the possibility that such cytosolic ds DNA,in naked form without binding to histone proteins,might be involved in the development of cell damage-triggered autoimmune responses.We also discuss the possible molecular mechanism by which cytosolic ds DNA can induce MHC molecules.It is reasonable to speculate that cytosolic ds DNA-induced MHC class Ⅰ is partially due to an autocrine/paracrine effect of type Ⅰ interferon(IFN).While the mechanism of cytosolic ds DNA-induced MHC class Ⅱ expression appears,at least partially,distinct from that mediated by IFN-γ.Further in-depth are required to clarify this picture.
文摘通过对牙鲆(Paralichthys olivaceus)MHC II B基因内含子1和外显子2直接测序的方法,从83个抗病牙鲆个体中共得到了85个等位基因,其中76个为新发现的等位基因。在扩增得到的263bp的外显子2中,共发现了60个多态性位点,其中33个是新发现的。不同的等位基因均以较低的频率出现,基因频率范围从0.006到0.069,基因型频率范围从0.012到0.169。通过序列分析,共发现了6种内含子1,其中4种是新发现的。内含子1中均包含了一个12bp的重复单元,其3'端含有一个富含CT/GT的区域。牙鲆MHC II B基因的高多态型和低频率揭示了牙鲆群体MHC基因资源的丰富性,为选择育种提供了可能。
