The innate immune response is a complex process involving multiple pathogen-recognition receptors, including toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors. Complement is...The innate immune response is a complex process involving multiple pathogen-recognition receptors, including toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors. Complement is also a critical component of innate immunity. While complement is known to interact with TLR-mediated signals, the interactions between NOD-like receptors and complement are not well understood. Here we report a synergistic interaction between C5a and Nod2 signaling in RAW 264.7 marophages. Long-term treatment with muramyl dipeptide (MDP), a NOD2 ligand, enhanced C5a-mediated expression of chemokine mRNAs in RAW 264.7 cells. This response was dependent on NOD2 expression and was associated with a decrease in expression of C5L2, a receptor for C5a which acts as a negative modulator of C5a receptor (C5aR) activity. MDP amplified C5a-mediated phosphorylation of p38 MAPK. Treatment of RAW264.7 cells with an inhibitor of p38 attenuated the synergistic effects of C5aon MDP-primed cells on MIP-2, but not MCP-1, mRNA. In contrast, inhibition of AKT prevented C5a stimulation of MCP-1, but not MIP-2, mRNA, in MDP-primed cells. Taken together, these data demonstrated a synergistic interaction between C5a and NOD2 in the regulation of chemokine expression in macrophages, associated with a down-regulation of C5L2, a negative regulator of C5a receptor activity.展开更多
AIM To investigate disease-specific gene expression profiles of peripheral blood mononuclear cells(PBMCs) from Crohn's disease(CD) patients in clinical remission.METHODS Patients with CD in clinical remission or w...AIM To investigate disease-specific gene expression profiles of peripheral blood mononuclear cells(PBMCs) from Crohn's disease(CD) patients in clinical remission.METHODS Patients with CD in clinical remission or with very low disease activity according to the Crohn's disease activity index were genotyped regarding nucleotidebinding oligomerization domain 2(NOD2),and PBMCs from wild-type(WT)-NOD2 patients,patients with homozygous or heterozygous NOD2 mutations and healthy donors were isolated for further analysis.The cells were cultured with vitamin D,peptidoglycan(PGN) and lipopolysaccharide(LPS) for defined periods of time before RNA was isolated and subjected to microarray analysis using Clariom S assays and quantitative realtime PCR.NOD2-and disease-specific gene expression profiles were evaluated with repeated measure ANOVA by a general linear model.RESULTS Employing microarray assays,a total of 267 genes were identified that were significantly up-or downregulated in PBMCs of WT-NOD2 patients,compared to healthy donors after challenge with vitamin D and/or a combination of LPS and PGN(P < 0.05;threshold:≥ 2-fold change).For further analysis by real-time PCR,genes with known impact on inflammation and immunity were selected that fulfilled predefined expression criteria.In a larger cohort of patients and controls,a disease-associated expression pattern,with higher transcript levels in vitamin D-treated PBMCs from patients,was observed for three of these genes,CLEC5 A(P < 0.030),lysozyme(LYZ;P < 0.047) and TREM1(P < 0.023).Six genes were found to be expressed in a NOD2-dependent manner(CD101,P < 0.002;CLEC5 A,P < 0.020;CXCL5,P < 0.009;IL-24,P < 0.044;ITGB2,P < 0.041;LYZ,P < 0.042).Interestingly,the highest transcript levels were observed in patients with heterozygous NOD2 mutations.CONCLUSION Our data identify CLEC5 A and LYZ as CD-and NOD2-associated genes of PBMCs and encourage further studies on their pathomechanistic roles.展开更多
BACKGROUND Crohn’s disease(CD)is characterized by a multifactorial etiology and a significant impact of genetic traits.While NOD2 mutations represent well established risk factors of CD,the role of other genes is inc...BACKGROUND Crohn’s disease(CD)is characterized by a multifactorial etiology and a significant impact of genetic traits.While NOD2 mutations represent well established risk factors of CD,the role of other genes is incompletely understood.AIM To challenge the hypothesis that single nucleotide polymorphisms(SNPs)in the genes CLEC5 A and CLEC7 A,two members of the C-type lectin domain family of pattern recognition receptors,may be associated with CD.METHODS SNPs in CLEC5 A,CLEC7 A and the known CD risk gene NOD2 were studied using real time PCR-based SNP assays.Therefore,DNA samples from 175 patients and 157 healthy donors were employed.Genotyping data were correlated with clinical characteristics of the patients and the results of gene expression data analyses.RESULTS In accordance with previous studies,rs2066844 and rs2066847 in NOD2 were found to be significantly associated with CD(allelic P values=0.0368 and 0.0474,respectively).Intriguingly,for genotype AA of rs1285933 in CLEC5 A,a potential association with CD(recessive P=0.0523;odds ratio=1.90)was observed.There were no associations between CD and SNPs rs2078178 and rs16910631 in CLEC7 A.Variants of rs1285933 had no impact on CLEC5 A gene expression.In contrast,genotype-dependent differences of CXCL5 expression in peripheral blood mononuclear cells were observed.There is no statistical interactionbetween the tested SNPs of NOD2 and CLEC5 A,suggesting of a novel pathway contributing to the disease.CONCLUSION Our data encourage enlarged follow-up studies to further address an association of SNP rs1285933 in CLEC5 A with CD.The C-type lectin domain family member also deserves attention regarding a potential role in the pathophysiology of CD.展开更多
Autoreactive CD8^(+)T cells,which play an indispensable role inβcell destruction,represent an emerging target for the prevention of type 1 diabetes(T1D).Altered peptide ligands(APLs)can efficiently induce antigen-spe...Autoreactive CD8^(+)T cells,which play an indispensable role inβcell destruction,represent an emerging target for the prevention of type 1 diabetes(T1D).Altered peptide ligands(APLs)can efficiently induce antigen-specific T cells anergy,apoptosis or shifts in the immune response.Here,we found that HLA-A*0201-restricted CD8^(+)T cell responses against a primaryβ-cell autoantigen insulin epitope InsB15–14 were present in both NOD.β2m null.HHD NOD mice and T1D patients.We generated several APL candidates for InsB15–14 by residue substitution at the p6 position.Only H6F exhibited an inhibitory effect on mInsB1_(5–14)-specific CD8^(+)T cell responses in vitro.H6F treatment significantly reduced the T1D incidence,which was accompanied by diminished autoreactive CD8^(+)T cell responses to mInsB15-14,inhibited infiltration of CD8^(+)and CD4^(+)T cells in the pancreas and reduced pro-inflammatory cytokine production in pancreatic and splenic T cells in NOD.β2m^(null).HHD mice.Mechanistically,H6F treatment significantly augmented a tiny portion of CD8^(+)CD25^(+)Foxp3^(+)T cells in the spleen and especially in the pancreas.This subset exhibited typical Treg phenotypes and required peptide-specific restimulation to exert immunosuppressive activity.Therefore,this APL H6F may be a promising candidate with potential clinical application value for antigen-specific prevention of T1D.展开更多
文摘The innate immune response is a complex process involving multiple pathogen-recognition receptors, including toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors. Complement is also a critical component of innate immunity. While complement is known to interact with TLR-mediated signals, the interactions between NOD-like receptors and complement are not well understood. Here we report a synergistic interaction between C5a and Nod2 signaling in RAW 264.7 marophages. Long-term treatment with muramyl dipeptide (MDP), a NOD2 ligand, enhanced C5a-mediated expression of chemokine mRNAs in RAW 264.7 cells. This response was dependent on NOD2 expression and was associated with a decrease in expression of C5L2, a receptor for C5a which acts as a negative modulator of C5a receptor (C5aR) activity. MDP amplified C5a-mediated phosphorylation of p38 MAPK. Treatment of RAW264.7 cells with an inhibitor of p38 attenuated the synergistic effects of C5aon MDP-primed cells on MIP-2, but not MCP-1, mRNA. In contrast, inhibition of AKT prevented C5a stimulation of MCP-1, but not MIP-2, mRNA, in MDP-primed cells. Taken together, these data demonstrated a synergistic interaction between C5a and NOD2 in the regulation of chemokine expression in macrophages, associated with a down-regulation of C5L2, a negative regulator of C5a receptor activity.
基金Supported by a grant from the Damp-Foundation(2016-04) to Schaffler H and Rohde S
文摘AIM To investigate disease-specific gene expression profiles of peripheral blood mononuclear cells(PBMCs) from Crohn's disease(CD) patients in clinical remission.METHODS Patients with CD in clinical remission or with very low disease activity according to the Crohn's disease activity index were genotyped regarding nucleotidebinding oligomerization domain 2(NOD2),and PBMCs from wild-type(WT)-NOD2 patients,patients with homozygous or heterozygous NOD2 mutations and healthy donors were isolated for further analysis.The cells were cultured with vitamin D,peptidoglycan(PGN) and lipopolysaccharide(LPS) for defined periods of time before RNA was isolated and subjected to microarray analysis using Clariom S assays and quantitative realtime PCR.NOD2-and disease-specific gene expression profiles were evaluated with repeated measure ANOVA by a general linear model.RESULTS Employing microarray assays,a total of 267 genes were identified that were significantly up-or downregulated in PBMCs of WT-NOD2 patients,compared to healthy donors after challenge with vitamin D and/or a combination of LPS and PGN(P < 0.05;threshold:≥ 2-fold change).For further analysis by real-time PCR,genes with known impact on inflammation and immunity were selected that fulfilled predefined expression criteria.In a larger cohort of patients and controls,a disease-associated expression pattern,with higher transcript levels in vitamin D-treated PBMCs from patients,was observed for three of these genes,CLEC5 A(P < 0.030),lysozyme(LYZ;P < 0.047) and TREM1(P < 0.023).Six genes were found to be expressed in a NOD2-dependent manner(CD101,P < 0.002;CLEC5 A,P < 0.020;CXCL5,P < 0.009;IL-24,P < 0.044;ITGB2,P < 0.041;LYZ,P < 0.042).Interestingly,the highest transcript levels were observed in patients with heterozygous NOD2 mutations.CONCLUSION Our data identify CLEC5 A and LYZ as CD-and NOD2-associated genes of PBMCs and encourage further studies on their pathomechanistic roles.
文摘BACKGROUND Crohn’s disease(CD)is characterized by a multifactorial etiology and a significant impact of genetic traits.While NOD2 mutations represent well established risk factors of CD,the role of other genes is incompletely understood.AIM To challenge the hypothesis that single nucleotide polymorphisms(SNPs)in the genes CLEC5 A and CLEC7 A,two members of the C-type lectin domain family of pattern recognition receptors,may be associated with CD.METHODS SNPs in CLEC5 A,CLEC7 A and the known CD risk gene NOD2 were studied using real time PCR-based SNP assays.Therefore,DNA samples from 175 patients and 157 healthy donors were employed.Genotyping data were correlated with clinical characteristics of the patients and the results of gene expression data analyses.RESULTS In accordance with previous studies,rs2066844 and rs2066847 in NOD2 were found to be significantly associated with CD(allelic P values=0.0368 and 0.0474,respectively).Intriguingly,for genotype AA of rs1285933 in CLEC5 A,a potential association with CD(recessive P=0.0523;odds ratio=1.90)was observed.There were no associations between CD and SNPs rs2078178 and rs16910631 in CLEC7 A.Variants of rs1285933 had no impact on CLEC5 A gene expression.In contrast,genotype-dependent differences of CXCL5 expression in peripheral blood mononuclear cells were observed.There is no statistical interactionbetween the tested SNPs of NOD2 and CLEC5 A,suggesting of a novel pathway contributing to the disease.CONCLUSION Our data encourage enlarged follow-up studies to further address an association of SNP rs1285933 in CLEC5 A with CD.The C-type lectin domain family member also deserves attention regarding a potential role in the pathophysiology of CD.
基金supported by the National Natural Science Foundation of China(No.31570931 and No.31771002)the National Key Project for Research&Development of China(Grant no.2016YFA0502204).
文摘Autoreactive CD8^(+)T cells,which play an indispensable role inβcell destruction,represent an emerging target for the prevention of type 1 diabetes(T1D).Altered peptide ligands(APLs)can efficiently induce antigen-specific T cells anergy,apoptosis or shifts in the immune response.Here,we found that HLA-A*0201-restricted CD8^(+)T cell responses against a primaryβ-cell autoantigen insulin epitope InsB15–14 were present in both NOD.β2m null.HHD NOD mice and T1D patients.We generated several APL candidates for InsB15–14 by residue substitution at the p6 position.Only H6F exhibited an inhibitory effect on mInsB1_(5–14)-specific CD8^(+)T cell responses in vitro.H6F treatment significantly reduced the T1D incidence,which was accompanied by diminished autoreactive CD8^(+)T cell responses to mInsB15-14,inhibited infiltration of CD8^(+)and CD4^(+)T cells in the pancreas and reduced pro-inflammatory cytokine production in pancreatic and splenic T cells in NOD.β2m^(null).HHD mice.Mechanistically,H6F treatment significantly augmented a tiny portion of CD8^(+)CD25^(+)Foxp3^(+)T cells in the spleen and especially in the pancreas.This subset exhibited typical Treg phenotypes and required peptide-specific restimulation to exert immunosuppressive activity.Therefore,this APL H6F may be a promising candidate with potential clinical application value for antigen-specific prevention of T1D.
