The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Florian Wiede - One of the best experts on this subject based on the ideXlab platform.
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PTPN2 and klrg1 regulate the generation and function of tissue resident memory cd8 t cells in skin
Journal of Experimental Medicine, 2021Co-Authors: Florian Wiede, Katharina Hochheiser, Teagan Wagner, David Freestone, Matthias H Enders, Moshe Olshansky, Brendan E Russ, Simone NussingAbstract:Tissue-resident memory T cells (TRM cells) are key elements of tissue immunity. Here, we investigated the role of the regulator of T cell receptor and cytokine signaling, PTPN2, in the formation and function of TRM cells in skin. PTPN2-deficient CD8+ T cells displayed a marked defect in generating CD69+ CD103+ TRM cells in response to herpes simplex virus type 1 (HSV-1) skin infection. This was accompanied by a reduction in the proportion of KLRG1- memory precursor cells and a transcriptional bias toward terminal differentiation. Of note, forced expression of KLRG1 was sufficient to impede TRM cell formation. Normalizing memory precursor frequencies by transferring equal numbers of KLRG1- cells restored TRM generation, demonstrating that PTPN2 impacted skin seeding with precursors rather than downstream TRM cell differentiation. Importantly, PTPN2-deficient TRM cells augmented skin autoimmunity but also afforded superior protection from HSV-1 infection. Our results emphasize that KLRG1 repression is required for optimal TRM cell formation in skin and reveal an important role of PTPN2 in regulating TRM cell functionality.
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PTPN2 and klrg1 regulate the generation and in skin
Journal of Experimental Medicine, 2021Co-Authors: Katharina Hochheiser, Florian Wiede, Teagan Wagner, David Freestone, Matthias H Enders, Moshe Olshansky, Brendan E Russ, Simone Nussing, Emma Grace Bawden, Asolina BraunAbstract:Tissue-resident memory T cells (TRM cells) are key elements of tissue immunity. Here, we investigated the role of the regulator of T cell receptor and cytokine signaling, PTPN2, in the formation and function of TRM cells in skin. PTPN2-deficient CD8+ T cells displayed a marked defect in generating CD69+ CD103+ TRM cells in response to herpes simplex virus type 1 (HSV-1) skin infection. This was accompanied by a reduction in the proportion of KLRG1- memory precursor cells and a transcriptional bias toward terminal differentiation. Of note, forced expression of KLRG1 was sufficient to impede TRM cell formation. Normalizing memory precursor frequencies by transferring equal numbers of KLRG1- cells restored TRM generation, demonstrating that PTPN2 impacted skin seeding with precursors rather than downstream TRM cell differentiation. Importantly, PTPN2-deficient TRM cells augmented skin autoimmunity but also afforded superior protection from HSV-1 infection. Our results emphasize that KLRG1 repression is required for optimal TRM cell formation in skin and reveal an important role of PTPN2 in regulating TRM cell functionality.
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PTPN2 deletion in t cells promotes anti tumour immunity and car t cell efficacy in solid tumours
bioRxiv, 2019Co-Authors: Florian Wiede, Shuwei Liang, Katharina Hochheiser, Garron T DoddAbstract:ABSTRACT Although adoptive T cell therapy has shown remarkable clinical efficacy in hematological malignancies, its success in combating solid tumours has been limited. Here we report that PTPN2 deletion in T cells enhances cancer immunosurveillance and the efficacy of adoptively transferred tumour-specific T cells. T cell-specific PTPN2 deficiency prevented tumours forming in aged mice heterozygous for the tumour suppressor p53. Adoptive transfer of PTPN2-deficient CD8+ T cells markedly repressed tumour formation in mice bearing mammary tumours. Moreover, PTPN2 deletion in T cells expressing a chimeric antigen receptor (CAR) specific for the oncoprotein HER-2 increased the activation of the Src family kinase LCK and cytokine-induced STAT-5 signalling thereby enhancing both CAR T cell activation and homing to CXCL9/10 expressing tumours to eradicate HER-2+ mammary tumours in vivo . Our findings define PTPN2 as a target for bolstering T-cell mediated anti-tumour immunity and CAR T cell therapy against solid tumours.
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t cell specific PTPN2 deficiency in nod mice accelerates the development of type 1 diabetes and autoimmune comorbidities
Diabetes, 2019Co-Authors: Florian Wiede, Thomas C Brodnicki, Pei Kee Goh, Yew Ann Leong, Gareth W Jones, Alan G Baxter, Simon Arnett Jones, Thomas W H KayAbstract:Genome-wide association studies have identified PTPN2 as an important non-MHC gene for autoimmunity. Single nucleotide polymorphisms that reduce PTPN2 expression have been linked with the development of various autoimmune disorders, including type 1 diabetes. The tyrosine phosphatase PTPN2 attenuates T-cell receptor and cytokine signaling in T cells to maintain peripheral tolerance, but the extent to which PTPN2 deficiency in T cells might influence type 1 diabetes onset remains unclear. NOD mice develop spontaneous autoimmune type 1 diabetes similar to that seen in humans. In this study, T-cell PTPN2 deficiency in NOD mice markedly accelerated the onset and increased the incidence of type 1 diabetes as well as that of other disorders, including colitis and Sjogren syndrome. Although PTPN2 deficiency in CD8+ T cells alone was able to drive the destruction of pancreatic β-cells and the onset of diabetes, T-cell-specific PTPN2 deficiency was also accompanied by increased CD4+ T-helper type 1 differentiation and T-follicular-helper cell polarization and increased the abundance of B cells in pancreatic islets as seen in human type 1 diabetes. These findings causally link PTPN2 deficiency in T cells with the development of type 1 diabetes and associated autoimmune comorbidities.
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reduced expression of phosphatase PTPN2 promotes pathogenic conversion of tregs in autoimmunity
Journal of Clinical Investigation, 2019Co-Authors: Mattias Svensson, Florian Wiede, Karen M Doody, Benjamin J Schmiedel, Sourya Bhattacharyya, Bharat Panwar, Shen Yang, Eugenio Santelli, Cristiano Sacchetti, Ravindra GujarAbstract:Genetic variants at the PTPN2 locus, which encodes the tyrosine phosphatase PTPN2, cause reduced gene expression and are linked to rheumatoid arthritis (RA) and other autoimmune diseases. PTPN2 inhibits signaling through the T cell and cytokine receptors, and loss of PTPN2 promotes T cell expansion and CD4- and CD8-driven autoimmunity. However, it remains unknown whether loss of PTPN2 in FoxP3+ regulatory T cells (Tregs) plays a role in autoimmunity. Here we aimed to model human autoimmune-predisposing PTPN2 variants, the presence of which results in a partial loss of PTPN2 expression, in mouse models of RA. We identified that reduced expression of PTPN2 enhanced the severity of autoimmune arthritis in the T cell-dependent SKG mouse model and demonstrated that this phenotype was mediated through a Treg-intrinsic mechanism. Mechanistically, we found that through dephosphorylation of STAT3, PTPN2 inhibits IL-6-driven pathogenic loss of FoxP3 after Tregs have acquired RORγt expression, at a stage when chromatin accessibility for STAT3-targeted IL-17-associated transcription factors is maximized. We conclude that PTPN2 promotes FoxP3 stability in mouse RORγt+ Tregs and that loss of function of PTPN2 in Tregs contributes to the association between PTPN2 and autoimmunity.
Decio L Eizirik - One of the best experts on this subject based on the ideXlab platform.
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PTPN2 a candidate gene for type 1 diabetes modulates pancreatic β cell apoptosis via regulation of the bh3 only protein bim
Diabetes, 2011Co-Authors: Izortze Santin, Fabrice Moore, Esteban Nicolas Gurzov, Maikel Luis Colli, Piero Marchetti, Lorella Marselli, Decio L EizirikAbstract:OBJECTIVE Genome-wide association studies allowed the identification of several associations between specific loci and type 1 diabetes (T1D). However, the mechanisms by which most candidate genes predispose to T1D remain unclear. We presently evaluated the mechanisms by which PTPN2 , a candidate gene for T1D, modulates β-cell apoptosis after exposure to type I and II interferons (IFNs), cytokines that contribute to β-cell loss in early T1D. RESEARCH DESIGN AND METHODS Small interfering RNAs were used to inhibit PTPN2, STAT1, Bim, and Jun NH 2 -terminal kinase 1 (JNK1) expression. Cell death was assessed by Hoescht propidium iodide staining. BAX translocation, Bim phosphorylation, cytochrome c release, and caspases 9 and 3 activation were measured by Western blot or immunofluorescence. RESULTS PTPN2 knockdown exacerbated type I IFN–induced apoptosis in INS-1E, primary rat, and human β-cells. PTPN2 silencing and exposure to type I and II IFNs induced BAX translocation to the mitochondria, cytochrome c release, and caspase 3 activation. There was also an increase in Bim phosphorylation that was at least in part regulated by JNK1. Of note, both Bim and JNK1 knockdown protected β-cells against IFN-induced apoptosis in PTPN2-silenced cells. CONCLUSIONS The present findings suggest that local IFN production may interact with a genetic factor ( PTPN2 ) to induce aberrant proapoptotic activity of the BH3-only protein Bim, resulting in increased β-cell apoptosis via JNK activation and the intrinsic apoptotic pathway. This is the first indication of a direct interaction between a candidate gene for T1D and the activation of a specific downstream proapoptotic pathway in β-cells.
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mda5 and PTPN2 two candidate genes for type 1 diabetes modify pancreatic β cell responses to the viral by product double stranded rna
Human Molecular Genetics, 2010Co-Authors: Maikel L. Colli, F Ortis, Fabrice Moore, Esteban Nicolas Gurzov, Decio L EizirikAbstract:β-Cell destruction in type 1 diabetes (T1D) is at least in part consequence of a ‘dialog’ between β-cells and immune system. This dialog may be affected by the individual's genetic background. We presently evaluated whether modulation of MDA5 and PTPN2, two candidate genes for T1D, affects β-cell responses to double-stranded RNA (dsRNA), a by-product of viral replication. These genes were selected following comparison between known candidate genes for T1D and genes expressed in pancreatic β-cells, as identified in previous array analysis. INS-1E cells and primary fluorescence-activated cell sorting-purified rat β-cells were transfected with small interference RNAs (siRNAs) targeting MDA5 or PTPN2 and subsequently exposed to intracellular synthetic dsRNA (polyinosinic–polycitidilic acid—PIC). Real-time RT–PCR, western blot and viability assays were performed to characterize gene/protein expression and viability. PIC increased MDA5 and PTPN2 mRNA expression, which was inhibited by the specific siRNAs. PIC triggered apoptosis in INS-1E and primary β-cells and this was augmented by PTPN2 knockdown (KD), although inhibition of MDA5 did not modify PIC-induced apoptosis. In contrast, MDA5 silencing decreased PIC-induced cytokine and chemokine expression, although inhibition of PTPN2 induced minor or no changes in these inflammatory mediators. These findings indicate that changes in MDA5 and PTPN2 expression modify β-cell responses to dsRNA. MDA5 regulates inflammatory signals, whereas PTPN2 may function as a defence mechanism against pro-apoptotic signals generated by dsRNA. These two candidate genes for T1D may thus modulate β-cell apoptosis and/or local release of inflammatory mediators in the course of a viral infection by acting, at least in part, at the pancreatic β-cell level.
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PTPN2 a candidate gene for type 1 diabetes modulates interferon gamma induced pancreatic beta cell apoptosis
Diabetes, 2009Co-Authors: Fabrice Moore, Maikel Luis Colli, Miriam Cnop, Mariana Igoillo Esteve, Alessandra K Cardozo, Daniel Andrade Da Cunha, Marco Bugliani, Piero Marchetti, Decio L EizirikAbstract:OBJECTIVE The pathogenesis of type 1 diabetes has a strong genetic component. Genome-wide association scans recently identified novel susceptibility genes including the phosphatases PTPN22 and PTPN2. We hypothesized that PTPN2 plays a direct role in β-cell demise and assessed PTPN2 expression in human islets and rat primary and clonal β-cells, besides evaluating its role in cytokine-induced signaling and β-cell apoptosis. RESEARCH DESIGN AND METHODS PTPN2 mRNA and protein expression was evaluated by real-time PCR and Western blot. Small interfering (si)RNAs were used to inhibit the expression of PTPN2 and downstream STAT1 in β-cells, allowing the assessment of cell death after cytokine treatment. RESULTS PTPN2 mRNA and protein are expressed in human islets and rat β-cells and upregulated by cytokines. Transfection with PTPN2 siRNAs inhibited basal- and cytokine-induced PTPN2 expression in rat β-cells and dispersed human islets cells. Decreased PTPN2 expression exacerbated interleukin (IL)-1β + interferon (IFN)-γ–induced β-cell apoptosis and turned IFN-γ alone into a proapoptotic signal. Inhibition of PTPN2 amplified IFN-γ–induced STAT1 phosphorylation, whereas double knockdown of both PTPN2 and STAT1 protected β-cells against cytokine-induced apoptosis, suggesting that STAT1 hyperactivation is responsible for the aggravation of cytokine-induced β-cell death in PTPN2-deficient cells. CONCLUSIONS We identified a functional role for the type 1 diabetes candidate gene PTPN2 in modulating IFN-γ signal transduction at the β-cell level. PTPN2 regulates cytokine-induced apoptosis and may thereby contribute to the pathogenesis of type 1 diabetes.
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MDA5 and PTPN2, two candidate genes for type 1 diabetes, modify pancreatic β-cell responses to the viral by-product double-stranded RNA
Human Molecular Genetics, 2009Co-Authors: Maikel L. Colli, F Ortis, Fabrice Moore, Esteban Nicolas Gurzov, Decio L EizirikAbstract:beta-Cell destruction in type 1 diabetes (T1D) is at least in part consequence of a 'dialog' between beta-cells and immune system. This dialog may be affected by the individual's genetic background. We presently evaluated whether modulation of MDA5 and PTPN2, two candidate genes for T1D, affects beta-cell responses to double-stranded RNA (dsRNA), a by-product of viral replication. These genes were selected following comparison between known candidate genes for T1D and genes expressed in pancreatic beta-cells, as identified in previous array analysis. INS-1E cells and primary fluorescence-activated cell sorting-purified rat beta-cells were transfected with small interference RNAs (siRNAs) targeting MDA5 or PTPN2 and subsequently exposed to intracellular synthetic dsRNA (polyinosinic-polycitidilic acid-PIC). Real-time RT-PCR, western blot and viability assays were performed to characterize gene/protein expression and viability. PIC increased MDA5 and PTPN2 mRNA expression, which was inhibited by the specific siRNAs. PIC triggered apoptosis in INS-1E and primary beta-cells and this was augmented by PTPN2 knockdown (KD), although inhibition of MDA5 did not modify PIC-induced apoptosis. In contrast, MDA5 silencing decreased PIC-induced cytokine and chemokine expression, although inhibition of PTPN2 induced minor or no changes in these inflammatory mediators. These findings indicate that changes in MDA5 and PTPN2 expression modify beta-cell responses to dsRNA. MDA5 regulates inflammatory signals, whereas PTPN2 may function as a defence mechanism against pro-apoptotic signals generated by dsRNA. These two candidate genes for T1D may thus modulate beta-cell apoptosis and/or local release of inflammatory mediators in the course of a viral infection by acting, at least in part, at the pancreatic beta-cell level.
Michael Scharl - One of the best experts on this subject based on the ideXlab platform.
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autoimmune susceptibility gene PTPN2 is required for clearance of adherent invasive escherichia coli by integrating bacterial uptake and lysosomal defence
Gut, 2021Co-Authors: Marianne R. Spalinger, Michael Scharl, Michel L Tremblay, Ali Shawki, Pritha Chatterjee, Vinicius Canale, Alina N Santos, Anica Sayocbecerra, James Borneman, Declan F MccoleAbstract:Objectives Alterations in the intestinal microbiota are linked with a wide range of autoimmune and inflammatory conditions, including inflammatory bowel diseases (IBD), where pathobionts penetrate the intestinal barrier and promote inflammatory reactions. In patients with IBD, the ability of intestinal macrophages to efficiently clear invading pathogens is compromised resulting in increased bacterial translocation and excessive immune reactions. Here, we investigated how an IBD-associated loss-of-function variant in the protein tyrosine phosphatase non-receptor type 2 (PTPN2) gene, or loss of PTPN2 expression affected the ability of macrophages to respond to invading bacteria. Design IBD patient-derived macrophages with wild-type (WT) PTPN2 or carrying the IBD-associated PTPN2 SNP, peritoneal macrophages from WT and constitutive PTPN2-knockout mice, as well as mice specifically lacking PTPN2 in macrophages were infected with non-invasive K12 Escherichia coli, the human adherent-invasive E. coli (AIEC) LF82, or a novel mouse AIEC (mAIEC) strain. Results Loss of PTPN2 severely compromises the ability of macrophages to clear invading bacteria. Specifically, loss of functional PTPN2 promoted pathobiont invasion/uptake into macrophages and intracellular survival/proliferation by three distinct mechanisms: Increased bacterial uptake was mediated by enhanced expression of carcinoembryonic antigen cellular adhesion molecule (CEACAM)1 and CEACAM6 in PTPN2-deficient cells, while reduced bacterial clearance resulted from defects in autophagy coupled with compromised lysosomal acidification. In vivo, mice lacking PTPN2 in macrophages were more susceptible to mAIEC infection and mAIEC-induced disease. Conclusions Our findings reveal a tripartite regulatory mechanism by which PTPN2 preserves macrophage antibacterial function, thus crucially contributing to host defence against invading bacteria.
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PTPN2 Regulates Interactions Between Macrophages and Intestinal Epithelial Cells to Promote Intestinal Barrier Function.
Gastroenterology, 2020Co-Authors: Marianne R. Spalinger, Ali Shawki, Vinicius Canale, Alina N Santos, Anica Sayoc-becerra, Moorthy Krishnan, Anna Niechcial, Nicole Obialo, Michael ScharlAbstract:Abstract Background & Aims The mechanisms by which macrophages regulate intestinal epithelial cell (IEC) barrier properties are poorly understood. Protein tyrosine phosphatase non-receptor type 2 (PTPN2) protects the IEC barrier from inflammation-induced disruption and regulates macrophage functions. We investigated whether PTPN2 controls interactions between IECs and macrophages to maintain intestinal barrier function. Methods Human IEC (Caco-2BBe/HT-29.cl19a cells) and mouse enteroid monolayers were co-cultured with human macrophages (THP-1, U937, primary monocyte-derived macrophages from patients with inflammatory bowel disease [IBD]) or mouse macrophages, respectively. We assessed barrier function (transepithelial electrical resistance [TEER] and permeability to 4 kDa fluorescently labeled dextran [FD4] or rhodamine B-dextran 70 kDa) and macrophage polarization. We analyzed intestinal tissues from mice with myeloid cell-specific deletion of PTPN2 (PTPN2-LysMCre mice) and mice without disruption of PTPN2 (controls); some mice were given injections of a neutralizing antibody against interleukin 6 (IL6). Proteins were knocked down in macrophages and/or IECs with small hairpin RNAs. Results Knockdown of PTPN2 in either macrophages and/or IECs increased the permeability of IEC monolayers, had a synergistic effect when knocked down from both cell types, and increased development of inflammatory macrophages in macrophage–IEC co-cultures. Colon lamina propria from PTPN2-LysMCre mice had significant increases in inflammatory macrophages; these mice had increased in vivo and ex vivo colon permeability to FD4 and reduced ex vivo colon TEER. Nanostring analysis revealed significant increases in expression of IL6 in colon macrophages from PTPN2-LysMCre mice. An IL6 blocking antibody reversed the effects of PTPN2-deficient macrophages, reducing permeability of IEC monolayers in culture and in PTPN2-LysMCre mice. Macrophages from patients with IBD carrying a single-nucleotide polymorphism associated with the disease (PTPN2 rs1893217) had the same features of PTPN2-deficient macrophages from mice, including reduced TEER and increased permeability in co-cultures with human IEC or mouse enteroid monolayers, which were restored by anti-IL6. Conclusions PTPN2 is required for interactions between macrophages and IECs; loss of PTPN2 from either cell type results in intestinal barrier defects, and loss from both cell types has a synergistic effect. We provide a mechanism by which PTPN2 gene variants compromise intestinal epithelial barrier function and increase risk of inflammatory disorders such as IBD.
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presence of PTPN2 snp rs1893217 enhances the anti inflammatory effect of spermidine
Inflammatory Bowel Diseases, 2020Co-Authors: Anna Niechcial, Declan F Mccole, Nicole Obialo, Claudia Gottier, Silvia Lang, Matthias Butter, Salomon M Manz, K Babler, Lisa Van Der Lely, Michael ScharlAbstract:Background The single nucleotide polymorphism (SNP) rs1893217 within the gene locus encoding PTPN2 represents a risk factor for inflammatory bowel disease (IBD). Our previous work demonstrated reduced PTPN2 activity and subsequently increased inflammatory signaling upon presence of SNP rs1893217. The naturally occurring polyamine spermidine reduces pro-inflammatory signaling via induction of PTPN2 activity; however, the effect of SNP rs1893217 on the anti-inflammatory potential of spermidine is still unknown. Here, we investigated how presence of SNP rs1893217 affects treatment efficacy of spermidine and whether it might serve as a potential biomarker for spermidine treatment. Methods Human T84 (wild-type [WT] for PTPN2 SNP rs1893217) and HT29 (heterozygous for PTPN2 SNP rs1893217) intestinal epithelial cells (IECs) were treated with several polyamines from the putrescine-spermidine pathway. T84 and HT29 IECs, THP-1 monocytes (WT and transfected with a lentiviral vector expressing PTPN2 SNP rs1893217) and genotyped, patient-derived peripheral blood mononuclear cells were challenged with IFN-γ and/or spermidine. Results Among the analyzed polyamines, spermidine was the most efficient activator of PTPN2 phosphatase activity, regardless of the PTPN2 genotype. Spermidine suppressed IFN-γ-induced STAT1 and STAT3 phosphorylation, along with decreased mRNA expression of ICAM-1, NOD2, and IFNG in IECs and monocytes. Of note, these effects were clearly more pronounced when the disease-associated PTPN2 C-variant in SNP rs1893217 was present. Conclusions Our data demonstrate that spermidine is the most potent polyamine in the putrescine-spermine axis for inducing PTPN2 enzymatic activity. The anti-inflammatory effect of spermidine is potentiated in the presence of SNP rs1893217, and this SNP might thus be a useful biomarker for possible spermidine-treatment in IBD patients.
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The presence of genetic risk variants within PTPN2 and PTPN22 is associated with intestinal microbiota alterations in Swiss IBD cohort patients.
PloS one, 2018Co-Authors: Bahtiyar Yilmaz, Marianne R. Spalinger, Luc Biedermann, Yannick Franc, Nicolas Fournier, Jean-benoit Rossel, Pascal Juillerat, Gerhard Rogler, Andrew J. Macpherson, Michael ScharlAbstract:Background Genetic risk factors, intestinal microbiota and a dysregulated immune system contribute to the pathogenesis of inflammatory bowel disease (IBD). We have previously demonstrated that dysfunction of protein tyrosine phosphatase non-receptor type 2 (PTPN2) and PTPN22 contributes to alterations of intestinal microbiota and the onset of chronic intestinal inflammation in vivo. Here, we investigated the influence of PTPN2 and PTPN22 gene variants on intestinal microbiota composition in IBD patients. Methods Bacterial DNA from mucosa-associated samples of 75 CD and 57 UC patients were sequenced using 16S rRNA sequencing approach. Microbial analysis, including alpha diversity, beta diversity and taxonomical analysis by comparing to PTPN2 (rs1893217) and PTPN22 (rs2476601) genotypes was performed in QIIME, the phyloseq R package and MaAsLin pipeline. Results In PTPN2 variant UC patients, we detected an increase in relative abundance of unassigned genera from Clostridiales and Lachnospiraceae families and reduction of Roseburia when compared to PTPN2 wild-type (WT) patients. Ruminoccocus was increased in PTPN22 variant UC patients. In CD patients with severe disease course, Faecalibacterium, Bilophila, Coprococcus, unclassified Erysipelotrichaeceae, unassigned genera from Clostridiales and Ruminococcaceae families were reduced and Bacteroides were increased in PTPN2 WT carriers, while Faecalibacterium, Bilophila, Coprococcus, and Erysipelotrichaeceae were reduced in PTPN22 WT patients when compared to patients with mild disease. In UC patients with severe disease, relative abundance of Lachnobacterium was reduced in PTPN2 and PTPN22 WT patients, Dorea was increased in samples from PTPN22 WT carriers and an unassigned genus from Ruminococcaceae gen. was increased in patients with PTPN2 variant genotype. Conclusions We identified that IBD-associated genetic risk variants, disease severity and the interaction of these factors are related to significant alterations in intestinal microbiota composition of IBD patients.
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PTPN2 as a promoter of colon carcinoma via reduction of inflammasome activation
Molecular and Cellular Oncology, 2018Co-Authors: Marianne R. Spalinger, Michael ScharlAbstract:We have recently demonstrated that macrophage-specific loss of Protein tyrosine phosphatase non-receptor type 2 (PTPN2) promotes inflammasome activation, resulting in protection from colorectal cancer. Here we place these findings in context with the role of inflammasomes in colorectal carcinoma, and with a recent study indicating that PTPN2-silencing promotes anti-cancer immunotherapy.
Fabrice Moore - One of the best experts on this subject based on the ideXlab platform.
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PTPN2 a candidate gene for type 1 diabetes modulates pancreatic β cell apoptosis via regulation of the bh3 only protein bim
Diabetes, 2011Co-Authors: Izortze Santin, Fabrice Moore, Esteban Nicolas Gurzov, Maikel Luis Colli, Piero Marchetti, Lorella Marselli, Decio L EizirikAbstract:OBJECTIVE Genome-wide association studies allowed the identification of several associations between specific loci and type 1 diabetes (T1D). However, the mechanisms by which most candidate genes predispose to T1D remain unclear. We presently evaluated the mechanisms by which PTPN2 , a candidate gene for T1D, modulates β-cell apoptosis after exposure to type I and II interferons (IFNs), cytokines that contribute to β-cell loss in early T1D. RESEARCH DESIGN AND METHODS Small interfering RNAs were used to inhibit PTPN2, STAT1, Bim, and Jun NH 2 -terminal kinase 1 (JNK1) expression. Cell death was assessed by Hoescht propidium iodide staining. BAX translocation, Bim phosphorylation, cytochrome c release, and caspases 9 and 3 activation were measured by Western blot or immunofluorescence. RESULTS PTPN2 knockdown exacerbated type I IFN–induced apoptosis in INS-1E, primary rat, and human β-cells. PTPN2 silencing and exposure to type I and II IFNs induced BAX translocation to the mitochondria, cytochrome c release, and caspase 3 activation. There was also an increase in Bim phosphorylation that was at least in part regulated by JNK1. Of note, both Bim and JNK1 knockdown protected β-cells against IFN-induced apoptosis in PTPN2-silenced cells. CONCLUSIONS The present findings suggest that local IFN production may interact with a genetic factor ( PTPN2 ) to induce aberrant proapoptotic activity of the BH3-only protein Bim, resulting in increased β-cell apoptosis via JNK activation and the intrinsic apoptotic pathway. This is the first indication of a direct interaction between a candidate gene for T1D and the activation of a specific downstream proapoptotic pathway in β-cells.
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mda5 and PTPN2 two candidate genes for type 1 diabetes modify pancreatic β cell responses to the viral by product double stranded rna
Human Molecular Genetics, 2010Co-Authors: Maikel L. Colli, F Ortis, Fabrice Moore, Esteban Nicolas Gurzov, Decio L EizirikAbstract:β-Cell destruction in type 1 diabetes (T1D) is at least in part consequence of a ‘dialog’ between β-cells and immune system. This dialog may be affected by the individual's genetic background. We presently evaluated whether modulation of MDA5 and PTPN2, two candidate genes for T1D, affects β-cell responses to double-stranded RNA (dsRNA), a by-product of viral replication. These genes were selected following comparison between known candidate genes for T1D and genes expressed in pancreatic β-cells, as identified in previous array analysis. INS-1E cells and primary fluorescence-activated cell sorting-purified rat β-cells were transfected with small interference RNAs (siRNAs) targeting MDA5 or PTPN2 and subsequently exposed to intracellular synthetic dsRNA (polyinosinic–polycitidilic acid—PIC). Real-time RT–PCR, western blot and viability assays were performed to characterize gene/protein expression and viability. PIC increased MDA5 and PTPN2 mRNA expression, which was inhibited by the specific siRNAs. PIC triggered apoptosis in INS-1E and primary β-cells and this was augmented by PTPN2 knockdown (KD), although inhibition of MDA5 did not modify PIC-induced apoptosis. In contrast, MDA5 silencing decreased PIC-induced cytokine and chemokine expression, although inhibition of PTPN2 induced minor or no changes in these inflammatory mediators. These findings indicate that changes in MDA5 and PTPN2 expression modify β-cell responses to dsRNA. MDA5 regulates inflammatory signals, whereas PTPN2 may function as a defence mechanism against pro-apoptotic signals generated by dsRNA. These two candidate genes for T1D may thus modulate β-cell apoptosis and/or local release of inflammatory mediators in the course of a viral infection by acting, at least in part, at the pancreatic β-cell level.
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PTPN2 a candidate gene for type 1 diabetes modulates interferon gamma induced pancreatic beta cell apoptosis
Diabetes, 2009Co-Authors: Fabrice Moore, Maikel Luis Colli, Miriam Cnop, Mariana Igoillo Esteve, Alessandra K Cardozo, Daniel Andrade Da Cunha, Marco Bugliani, Piero Marchetti, Decio L EizirikAbstract:OBJECTIVE The pathogenesis of type 1 diabetes has a strong genetic component. Genome-wide association scans recently identified novel susceptibility genes including the phosphatases PTPN22 and PTPN2. We hypothesized that PTPN2 plays a direct role in β-cell demise and assessed PTPN2 expression in human islets and rat primary and clonal β-cells, besides evaluating its role in cytokine-induced signaling and β-cell apoptosis. RESEARCH DESIGN AND METHODS PTPN2 mRNA and protein expression was evaluated by real-time PCR and Western blot. Small interfering (si)RNAs were used to inhibit the expression of PTPN2 and downstream STAT1 in β-cells, allowing the assessment of cell death after cytokine treatment. RESULTS PTPN2 mRNA and protein are expressed in human islets and rat β-cells and upregulated by cytokines. Transfection with PTPN2 siRNAs inhibited basal- and cytokine-induced PTPN2 expression in rat β-cells and dispersed human islets cells. Decreased PTPN2 expression exacerbated interleukin (IL)-1β + interferon (IFN)-γ–induced β-cell apoptosis and turned IFN-γ alone into a proapoptotic signal. Inhibition of PTPN2 amplified IFN-γ–induced STAT1 phosphorylation, whereas double knockdown of both PTPN2 and STAT1 protected β-cells against cytokine-induced apoptosis, suggesting that STAT1 hyperactivation is responsible for the aggravation of cytokine-induced β-cell death in PTPN2-deficient cells. CONCLUSIONS We identified a functional role for the type 1 diabetes candidate gene PTPN2 in modulating IFN-γ signal transduction at the β-cell level. PTPN2 regulates cytokine-induced apoptosis and may thereby contribute to the pathogenesis of type 1 diabetes.
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MDA5 and PTPN2, two candidate genes for type 1 diabetes, modify pancreatic β-cell responses to the viral by-product double-stranded RNA
Human Molecular Genetics, 2009Co-Authors: Maikel L. Colli, F Ortis, Fabrice Moore, Esteban Nicolas Gurzov, Decio L EizirikAbstract:beta-Cell destruction in type 1 diabetes (T1D) is at least in part consequence of a 'dialog' between beta-cells and immune system. This dialog may be affected by the individual's genetic background. We presently evaluated whether modulation of MDA5 and PTPN2, two candidate genes for T1D, affects beta-cell responses to double-stranded RNA (dsRNA), a by-product of viral replication. These genes were selected following comparison between known candidate genes for T1D and genes expressed in pancreatic beta-cells, as identified in previous array analysis. INS-1E cells and primary fluorescence-activated cell sorting-purified rat beta-cells were transfected with small interference RNAs (siRNAs) targeting MDA5 or PTPN2 and subsequently exposed to intracellular synthetic dsRNA (polyinosinic-polycitidilic acid-PIC). Real-time RT-PCR, western blot and viability assays were performed to characterize gene/protein expression and viability. PIC increased MDA5 and PTPN2 mRNA expression, which was inhibited by the specific siRNAs. PIC triggered apoptosis in INS-1E and primary beta-cells and this was augmented by PTPN2 knockdown (KD), although inhibition of MDA5 did not modify PIC-induced apoptosis. In contrast, MDA5 silencing decreased PIC-induced cytokine and chemokine expression, although inhibition of PTPN2 induced minor or no changes in these inflammatory mediators. These findings indicate that changes in MDA5 and PTPN2 expression modify beta-cell responses to dsRNA. MDA5 regulates inflammatory signals, whereas PTPN2 may function as a defence mechanism against pro-apoptotic signals generated by dsRNA. These two candidate genes for T1D may thus modulate beta-cell apoptosis and/or local release of inflammatory mediators in the course of a viral infection by acting, at least in part, at the pancreatic beta-cell level.
Marianne R. Spalinger - One of the best experts on this subject based on the ideXlab platform.
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autoimmune susceptibility gene PTPN2 is required for clearance of adherent invasive escherichia coli by integrating bacterial uptake and lysosomal defence
Gut, 2021Co-Authors: Marianne R. Spalinger, Michael Scharl, Michel L Tremblay, Ali Shawki, Pritha Chatterjee, Vinicius Canale, Alina N Santos, Anica Sayocbecerra, James Borneman, Declan F MccoleAbstract:Objectives Alterations in the intestinal microbiota are linked with a wide range of autoimmune and inflammatory conditions, including inflammatory bowel diseases (IBD), where pathobionts penetrate the intestinal barrier and promote inflammatory reactions. In patients with IBD, the ability of intestinal macrophages to efficiently clear invading pathogens is compromised resulting in increased bacterial translocation and excessive immune reactions. Here, we investigated how an IBD-associated loss-of-function variant in the protein tyrosine phosphatase non-receptor type 2 (PTPN2) gene, or loss of PTPN2 expression affected the ability of macrophages to respond to invading bacteria. Design IBD patient-derived macrophages with wild-type (WT) PTPN2 or carrying the IBD-associated PTPN2 SNP, peritoneal macrophages from WT and constitutive PTPN2-knockout mice, as well as mice specifically lacking PTPN2 in macrophages were infected with non-invasive K12 Escherichia coli, the human adherent-invasive E. coli (AIEC) LF82, or a novel mouse AIEC (mAIEC) strain. Results Loss of PTPN2 severely compromises the ability of macrophages to clear invading bacteria. Specifically, loss of functional PTPN2 promoted pathobiont invasion/uptake into macrophages and intracellular survival/proliferation by three distinct mechanisms: Increased bacterial uptake was mediated by enhanced expression of carcinoembryonic antigen cellular adhesion molecule (CEACAM)1 and CEACAM6 in PTPN2-deficient cells, while reduced bacterial clearance resulted from defects in autophagy coupled with compromised lysosomal acidification. In vivo, mice lacking PTPN2 in macrophages were more susceptible to mAIEC infection and mAIEC-induced disease. Conclusions Our findings reveal a tripartite regulatory mechanism by which PTPN2 preserves macrophage antibacterial function, thus crucially contributing to host defence against invading bacteria.
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PTPN2 Regulates Interactions Between Macrophages and Intestinal Epithelial Cells to Promote Intestinal Barrier Function.
Gastroenterology, 2020Co-Authors: Marianne R. Spalinger, Ali Shawki, Vinicius Canale, Alina N Santos, Anica Sayoc-becerra, Moorthy Krishnan, Anna Niechcial, Nicole Obialo, Michael ScharlAbstract:Abstract Background & Aims The mechanisms by which macrophages regulate intestinal epithelial cell (IEC) barrier properties are poorly understood. Protein tyrosine phosphatase non-receptor type 2 (PTPN2) protects the IEC barrier from inflammation-induced disruption and regulates macrophage functions. We investigated whether PTPN2 controls interactions between IECs and macrophages to maintain intestinal barrier function. Methods Human IEC (Caco-2BBe/HT-29.cl19a cells) and mouse enteroid monolayers were co-cultured with human macrophages (THP-1, U937, primary monocyte-derived macrophages from patients with inflammatory bowel disease [IBD]) or mouse macrophages, respectively. We assessed barrier function (transepithelial electrical resistance [TEER] and permeability to 4 kDa fluorescently labeled dextran [FD4] or rhodamine B-dextran 70 kDa) and macrophage polarization. We analyzed intestinal tissues from mice with myeloid cell-specific deletion of PTPN2 (PTPN2-LysMCre mice) and mice without disruption of PTPN2 (controls); some mice were given injections of a neutralizing antibody against interleukin 6 (IL6). Proteins were knocked down in macrophages and/or IECs with small hairpin RNAs. Results Knockdown of PTPN2 in either macrophages and/or IECs increased the permeability of IEC monolayers, had a synergistic effect when knocked down from both cell types, and increased development of inflammatory macrophages in macrophage–IEC co-cultures. Colon lamina propria from PTPN2-LysMCre mice had significant increases in inflammatory macrophages; these mice had increased in vivo and ex vivo colon permeability to FD4 and reduced ex vivo colon TEER. Nanostring analysis revealed significant increases in expression of IL6 in colon macrophages from PTPN2-LysMCre mice. An IL6 blocking antibody reversed the effects of PTPN2-deficient macrophages, reducing permeability of IEC monolayers in culture and in PTPN2-LysMCre mice. Macrophages from patients with IBD carrying a single-nucleotide polymorphism associated with the disease (PTPN2 rs1893217) had the same features of PTPN2-deficient macrophages from mice, including reduced TEER and increased permeability in co-cultures with human IEC or mouse enteroid monolayers, which were restored by anti-IL6. Conclusions PTPN2 is required for interactions between macrophages and IECs; loss of PTPN2 from either cell type results in intestinal barrier defects, and loss from both cell types has a synergistic effect. We provide a mechanism by which PTPN2 gene variants compromise intestinal epithelial barrier function and increase risk of inflammatory disorders such as IBD.
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the autoimmune susceptibility gene PTPN2 restricts expansion of a novel mouse adherent invasive e coli
Gut microbes, 2020Co-Authors: Ali Shawki, Marianne R. Spalinger, Pritha Chatterjee, Vinicius Canale, Alina N Santos, Rocio Ramirez, Paul M Ruegger, Anica Sayoc, Jonathan Mitchell, John C MacbethAbstract:Inflammatory bowel disease (IBD) pathogenesis involves significant contributions from genetic and environmental factors. Loss-of-function single-nucleotide polymorphisms (SNPs) in the protein tyrosine phosphatase non-receptor type 2 (PTPN2) gene increase IBD risk and are associated with altered microbiome population dynamics in IBD. Expansion of intestinal pathobionts, such as adherent-invasive E. coli (AIEC), is strongly implicated in IBD pathogenesis as AIEC increases pro-inflammatory cytokine production and alters tight junction protein regulation - suggesting a potential mechanism of pathogen-induced barrier dysfunction and inflammation. We aimed to determine if PTPN2 deficiency alters intestinal microbiome composition to promote expansion of specific bacteria with pathogenic properties. In mice constitutively lacking PTPN2, we identified increased abundance of a novel mouse AIEC (mAIEC) that showed similar adherence and invasion of intestinal epithelial cells, but greater survival in macrophages, to the IBD-associated AIEC, LF82. Furthermore, mAIEC caused disease when administered to mice lacking segmented-filamentous bacteria (SFB), and in germ-free mice but only when reconstituted with a microbiome, thus supporting its classification as a pathobiont, not a pathogen. Moreover, mAIEC infection increased the severity of, and prevented recovery from, induced colitis. Although mAIEC genome sequence analysis showed >90% similarity to LF82, mAIEC contained putative virulence genes with >50% difference in gene/protein identities from LF82 indicating potentially distinct genetic features of mAIEC. We show for the first time that an IBD susceptibility gene, PTPN2, modulates the gut microbiome to protect against a novel pathobiont. This study generates new insights into gene-environment-microbiome interactions in IBD and identifies a new model to study AIEC-host interactions.
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the autoimmune susceptibility gene PTPN2 restricts expansion of a novel mouse adherent invasive e coli
bioRxiv, 2019Co-Authors: Ali Shawki, Marianne R. Spalinger, Pritha Chatterjee, Alina N Santos, Paul M Ruegger, Anica Sayoc, Jonathan Mitchell, John C Macbeth, Rocio Alvarez, Michel L TremblayAbstract:Abstract Inflammatory bowel diseases (IBD) involve genetic and environmental factors that play major roles in disease pathogenesis. Loss-of-function single-nucleotide polymorphisms (SNPs) in the protein tyrosine phosphatase non-receptor type 2 (PTPN2) gene increase the risk of IBD and are associated with altered microbiome population dynamics in IBD. Moreover, expansion of intestinal pathobionts, such as adherent-invasive E. coli (AIEC), is strongly implicated in the pathogenesis of IBD as AIEC increases pro-inflammatory cytokine production and alters tight junction protein regulation suggesting a potential mechanism of pathogen-induced barrier dysfunction and inflammation. The aim of this study was to identify if PTPN2 deficiency disturbs the composition of the intestinal microbiome to promote expansion of specific bacteria with pathogenic properties. In mice constitutively lacking PTPN2 we identified increased abundance of a novel adherent-invasive E. coli (AIEC) that showed similar adherence and invasion of intestinal epithelial cells, but greater survival in macrophages to the IBD associated AIEC, LF82. Furthermore, we confirmed this novel mouse AIEC (mAIEC) caused disease when administered to germ-free and mice lacking segmented-filamentous bacteria (SFB). Moreover, mAIEC infection increased severity of and prevented recovery from dextran-sodium sulfate (DSS)-induced colitis. mAIEC genome sequence analysis showed >90% similarity to LF82. Interestingly, mAIEC contained distinct attachment genes not found in LF82 thereby also demonstrating the novelty of this AIEC. We show here for the first time that an IBD susceptibility gene, PTPN2, plays a key role in modulating the gut microbiome to protect against a novel pathobiont. This study generates new insights into gene-environment-microbiome interactions in IBD.
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The presence of genetic risk variants within PTPN2 and PTPN22 is associated with intestinal microbiota alterations in Swiss IBD cohort patients.
PloS one, 2018Co-Authors: Bahtiyar Yilmaz, Marianne R. Spalinger, Luc Biedermann, Yannick Franc, Nicolas Fournier, Jean-benoit Rossel, Pascal Juillerat, Gerhard Rogler, Andrew J. Macpherson, Michael ScharlAbstract:Background Genetic risk factors, intestinal microbiota and a dysregulated immune system contribute to the pathogenesis of inflammatory bowel disease (IBD). We have previously demonstrated that dysfunction of protein tyrosine phosphatase non-receptor type 2 (PTPN2) and PTPN22 contributes to alterations of intestinal microbiota and the onset of chronic intestinal inflammation in vivo. Here, we investigated the influence of PTPN2 and PTPN22 gene variants on intestinal microbiota composition in IBD patients. Methods Bacterial DNA from mucosa-associated samples of 75 CD and 57 UC patients were sequenced using 16S rRNA sequencing approach. Microbial analysis, including alpha diversity, beta diversity and taxonomical analysis by comparing to PTPN2 (rs1893217) and PTPN22 (rs2476601) genotypes was performed in QIIME, the phyloseq R package and MaAsLin pipeline. Results In PTPN2 variant UC patients, we detected an increase in relative abundance of unassigned genera from Clostridiales and Lachnospiraceae families and reduction of Roseburia when compared to PTPN2 wild-type (WT) patients. Ruminoccocus was increased in PTPN22 variant UC patients. In CD patients with severe disease course, Faecalibacterium, Bilophila, Coprococcus, unclassified Erysipelotrichaeceae, unassigned genera from Clostridiales and Ruminococcaceae families were reduced and Bacteroides were increased in PTPN2 WT carriers, while Faecalibacterium, Bilophila, Coprococcus, and Erysipelotrichaeceae were reduced in PTPN22 WT patients when compared to patients with mild disease. In UC patients with severe disease, relative abundance of Lachnobacterium was reduced in PTPN2 and PTPN22 WT patients, Dorea was increased in samples from PTPN22 WT carriers and an unassigned genus from Ruminococcaceae gen. was increased in patients with PTPN2 variant genotype. Conclusions We identified that IBD-associated genetic risk variants, disease severity and the interaction of these factors are related to significant alterations in intestinal microbiota composition of IBD patients.