RESUMEN
Obesity is a major driver of cancer, especially hepatocellular carcinoma (HCC). The prevailing view is that non-alcoholic steatohepatitis (NASH) and fibrosis or cirrhosis are required for HCC in obesity. Here, we report that NASH and fibrosis and HCC in obesity can be dissociated. We show that the oxidative hepatic environment in obesity inactivates the STAT-1 and STAT-3 phosphatase T cell protein tyrosine phosphatase (TCPTP) and increases STAT-1 and STAT-3 signaling. TCPTP deletion in hepatocytes promoted T cell recruitment and ensuing NASH and fibrosis as well as HCC in obese C57BL/6 mice that normally do not develop NASH and fibrosis or HCC. Attenuating the enhanced STAT-1 signaling prevented T cell recruitment and NASH and fibrosis but did not prevent HCC. By contrast, correcting STAT-3 signaling prevented HCC without affecting NASH and fibrosis. TCPTP-deletion in hepatocytes also markedly accelerated HCC in mice treated with a chemical carcinogen that promotes HCC without NASH and fibrosis. Our studies reveal how obesity-associated hepatic oxidative stress can independently contribute to the pathogenesis of NASH, fibrosis, and HCC.
Asunto(s)
Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Enfermedad del Hígado Graso no Alcohólico/patología , Obesidad/patología , Factor de Transcripción STAT1/metabolismo , Factor de Transcripción STAT3/metabolismo , Animales , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Carcinoma Hepatocelular/metabolismo , Dieta Alta en Grasa , Modelos Animales de Enfermedad , Hepatocitos/metabolismo , Humanos , Hígado/metabolismo , Hígado/patología , Cirrosis Hepática/metabolismo , Cirrosis Hepática/patología , Neoplasias Hepáticas/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Obesidad/metabolismo , Estrés Oxidativo , Proteína Tirosina Fosfatasa no Receptora Tipo 2/deficiencia , Proteína Tirosina Fosfatasa no Receptora Tipo 2/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 2/metabolismo , Transducción de SeñalRESUMEN
The cytokine IL-6 controls the survival, proliferation and effector characteristics of lymphocytes through activation of the transcription factors STAT1 and STAT3. While STAT3 activity is an ever-present feature of IL-6 signaling in CD4+ T cells, prior activation via the T cell antigen receptor limits IL-6's control of STAT1 in effector and memory populations. Here we found that phosphorylation of STAT1 in response to IL-6 was regulated by the tyrosine phosphatases PTPN2 and PTPN22 expressed in response to the activation of naïve CD4+ T cells. Transcriptomics and chromatin immunoprecipitation-sequencing (ChIP-seq) of IL-6 responses in naïve and effector memory CD4+ T cells showed how the suppression of STAT1 activation shaped the functional identity and effector characteristics of memory CD4+ T cells. Thus, tyrosine phosphatases induced by the activation of naïve T cells determine the way activated or memory CD4+ T cells sense and interpret cytokine signals.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Factor de Transcripción STAT1/metabolismo , Transducción de Señal , Animales , Artritis Reumatoide/enzimología , Artritis Reumatoide/patología , Linfocitos T CD4-Positivos/enzimología , Células CHO , Células Cultivadas , Cricetulus , Regulación de la Expresión Génica , Humanos , Memoria Inmunológica , Interleucina-6/fisiología , Activación de Linfocitos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Regiones Promotoras Genéticas , Proteína Tirosina Fosfatasa no Receptora Tipo 2/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores de Interleucina-6/fisiología , Membrana Sinovial/inmunología , Transcripción GenéticaRESUMEN
The primary task of white adipose tissue (WAT) is the storage of lipids. However, "beige" adipocytes also exist in WAT. Beige adipocytes burn fat and dissipate the energy as heat, but their abundance is diminished in obesity. Stimulating beige adipocyte development, or WAT browning, increases energy expenditure and holds potential for combating metabolic disease and obesity. Here, we report that insulin and leptin act together on hypothalamic neurons to promote WAT browning and weight loss. Deletion of the phosphatases PTP1B and TCPTP enhanced insulin and leptin signaling in proopiomelanocortin neurons and prevented diet-induced obesity by increasing WAT browning and energy expenditure. The coinfusion of insulin plus leptin into the CNS or the activation of proopiomelanocortin neurons also increased WAT browning and decreased adiposity. Our findings identify a homeostatic mechanism for coordinating the status of energy stores, as relayed by insulin and leptin, with the central control of WAT browning.
Asunto(s)
Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Insulina/metabolismo , Leptina/metabolismo , Proopiomelanocortina/metabolismo , Adiposidad , Animales , Regulación de la Temperatura Corporal , Ratones Endogámicos C57BL , Ratones Noqueados , Neuronas/metabolismo , Obesidad/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 1/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 2/metabolismoRESUMEN
Central to adaptive immunity is the interaction between the αß T cell receptor (TCR) and peptide presented by the major histocompatibility complex (MHC) molecule. Presumably reflecting TCR-MHC bias and T cell signaling constraints, the TCR universally adopts a canonical polarity atop the MHC. We report the structures of two TCRs, derived from human induced T regulatory (iT(reg)) cells, complexed to an MHC class II molecule presenting a proinsulin-derived peptide. The ternary complexes revealed a 180° polarity reversal compared to all other TCR-peptide-MHC complex structures. Namely, the iT(reg) TCR α-chain and ß-chain are overlaid with the α-chain and ß-chain of MHC class II, respectively. Nevertheless, this TCR interaction elicited a peptide-reactive, MHC-restricted T cell signal. Thus TCRs are not 'hardwired' to interact with MHC molecules in a stereotypic manner to elicit a T cell signal, a finding that fundamentally challenges our understanding of TCR recognition.
Asunto(s)
Autoantígenos/metabolismo , Complejo Mayor de Histocompatibilidad/inmunología , Receptores de Antígenos de Linfocitos T/metabolismo , Inmunidad Adaptativa , Presentación de Antígeno , Autoantígenos/química , Autoantígenos/genética , Células Cultivadas , Antígeno HLA-DR4/química , Antígeno HLA-DR4/genética , Antígeno HLA-DR4/metabolismo , Antígenos de Histocompatibilidad Clase II/química , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase II/metabolismo , Humanos , Complejo Mayor de Histocompatibilidad/genética , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Proinsulina/química , Proinsulina/genética , Proinsulina/inmunología , Dominios y Motivos de Interacción de Proteínas , Receptores de Antígenos de Linfocitos T/química , Receptores de Antígenos de Linfocitos T/genética , Linfocitos T Reguladores/inmunologíaRESUMEN
The anti-viral T cell response is drawn from the naive T cell repertoire. During influenza infection, the CD8+ T cell response to an H-2Db-restricted nucleoprotein epitope (NP366) is characterized by preferential expansion of T cells bearing TRBV13+ T cell receptors (TCRs) and avoidance of TRBV17+ T cells, despite the latter dominating the naive precursor repertoire. We found two TRBV17+ TCRs that bound H-2Db-NP366 with a 180° reversed polarity compared to the canonical TCR-pMHC-I docking. The TRBV17 ß-chain dominated the interaction and, whereas the complementarity determining region-3 (CDR3) loops exclusively mediated contacts with the MHC-I, peptide specificity was attributable to germline-encoded recognition. Nevertheless, the TRBV17+ TCR exhibited moderate affinity toward H-2Db-NP366 and was capable of signal transduction. Thus, the naive CD8+ T cell pool can comprise TCRs adopting reversed pMHC-I docking modes that limit their involvement in the immune response.
Asunto(s)
Antígenos de Histocompatibilidad Clase I/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Animales , Linfocitos T CD8-positivos/inmunología , Línea Celular , Línea Celular Tumoral , Cristalografía por Rayos X/métodos , Epítopos/inmunología , Femenino , Células HEK293 , Humanos , Células Jurkat , Ratones , Ratones Endogámicos C57BL , Modelos MolecularesRESUMEN
Although adoptive T-cell therapy has shown remarkable clinical efficacy in haematological 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.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Inmunoterapia Adoptiva/métodos , Activación de Linfocitos/inmunología , Neoplasias/terapia , Proteína Tirosina Fosfatasa no Receptora Tipo 2/fisiología , Receptor ErbB-2/fisiología , Receptores de Antígenos de Linfocitos T/inmunología , Traslado Adoptivo , Animales , Presentación de Antígeno/inmunología , Femenino , Humanos , Masculino , Ratones , Ratones Noqueados , Ratones Transgénicos , Neoplasias/genética , Neoplasias/inmunología , Transducción de SeñalRESUMEN
Protein tyrosine phosphatase 1B (PTP1B) and T-cell protein tyrosine phosphatase (TC-PTP) play non-redundant negative regulatory roles in T-cell activation, tumor antigen presentation, insulin and leptin signaling, and are potential targets for several therapeutic applications. Here, we report the development of a highly potent and selective small molecule degrader DU-14 for both PTP1B and TC-PTP. DU-14 mediated PTP1B and TC-PTP degradation requires both target protein(s) and VHL E3 ligase engagement and is also ubiquitination- and proteasome-dependent. DU-14 enhances IFN-γ induced JAK1/2-STAT1 pathway activation and promotes MHC-I expression in tumor cells. DU-14 also activates CD8+ T-cells and augments STAT1 and STAT5 phosphorylation. Importantly, DU-14 induces PTP1B and TC-PTP degradation in vivo and suppresses MC38 syngeneic tumor growth. The results indicate that DU-14, as the first PTP1B and TC-PTP dual degrader, merits further development for treating cancer and other indications.
Asunto(s)
Neoplasias , Proteína Tirosina Fosfatasa no Receptora Tipo 2 , Humanos , Proteína Tirosina Fosfatasa no Receptora Tipo 2/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 1/metabolismo , Linfocitos T CD8-positivos/metabolismo , Neoplasias/tratamiento farmacológico , Fosforilación , InmunoterapiaRESUMEN
The CC-chemokine receptor 6 (CCR6) can be detected on naive and activated B cells. Counterintuitively, its absence accelerates the appearance of germinal centres (GCs) and increases the production of low-affinity antibodies. The detailed mechanism of CCR6 function during the humoral response has remained elusive, but previously we identified a distinct CCR6high B-cell population in vivo early after antigenic challenge. In this study, we defined this population specifically as early, activated pre-GC B cells. In accordance, we show that CCR6 is upregulated rapidly within hours on the protein or mRNA level after activation in vitro. In addition, only activated B cells migrated specifically towards CCL20, the specific ligand for CCR6. Lack of CCR6 increased the dark zone/light zone ratio of GC and led to decreased antigen-specific IgG1 and IgG2a antibody generation in a B-cell intrinsic manner in mixed bone marrow chimeras. In contrast, antigen-specific IgM responses were normal. Hence, CCR6 negatively regulates entry of activated, antigen-specific pre-GC B cells into the GC reaction.
Asunto(s)
Formación de Anticuerpos/inmunología , Linfocitos B/metabolismo , Centro Germinal/metabolismo , Receptores CCR6/metabolismo , Animales , Formación de Anticuerpos/efectos de los fármacos , Linfocitos B/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Quimiocina CCL20/farmacología , Citometría de Flujo , Centro Germinal/efectos de los fármacos , Cinética , Activación de Linfocitos/efectos de los fármacos , Ratones Endogámicos C57BL , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores CCR6/genética , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Non-coding single nucleotide polymorphisms that repress PTPN2 expression have been linked with the development of type 1 diabetes, rheumatoid arthritis and Crohn's disease. PTPN2 attenuates CD8+ T cell responses to self and prevents overt autoreactivity in the context of T cell homeostasis and antigen cross-presentation. The role of PTPN2 in other immune subsets in the development of autoimmunity remains unclear. Here we show that the inducible deletion of PTPN2 in hematopoietic compartment of adult non-autoimmune prone mice results in systemic inflammation and autoimmunity. PTPN2-deficient mice had increased inflammatory monocytes, B cells and effector T cells in lymphoid and non-lymphoid tissues and exhibited symptoms of dermatitis, glomerulonephritis, pancreatitis and overt liver disease. Autoimmunity was characterised by the formation of germinal centers in the spleen and associated with markedly increased germinal center B cells and T follicular helper (Tfh) cells and circulating anti-nuclear antibodies, inflammatory cytokines and immunoglobulins. CD8+ T cell proliferative responses were enhanced, and interleukin-21-induced STAT-3 signalling in Tfh cells and B cells was increased and accompanied by enhanced B cell proliferation ex vivo. These results indicate that deficiencies in PTPN2 across multiple immune lineages, including naive T cells, Tfh cells and B cells, contribute to the development of autoimmunity.
Asunto(s)
Autoinmunidad/genética , Linfocitos B/inmunología , Linfocitos B/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 2/deficiencia , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Colaboradores-Inductores/metabolismo , Animales , Formación de Anticuerpos/genética , Formación de Anticuerpos/inmunología , Femenino , Eliminación de Gen , Centro Germinal/inmunología , Centro Germinal/metabolismo , Hematopoyesis/genética , Hematopoyesis/inmunología , Inflamación/inmunología , Inflamación/metabolismo , Interleucinas/metabolismo , Ratones , Ratones Noqueados , Ratones Transgénicos , Factor de Transcripción STAT3/metabolismo , Transducción de SeñalRESUMEN
AIMS/HYPOTHESIS: In obesity oxidative stress is thought to contribute to the development of insulin resistance, non-alcoholic fatty liver disease and the progression to non-alcoholic steatohepatitis. Our aim was to examine the precise contributions of hepatocyte-derived H2O2 to liver pathophysiology. METHODS: Glutathione peroxidase (GPX) 1 is an antioxidant enzyme that is abundant in the liver and converts H2O2 to water. We generated Gpx1 lox/lox mice to conditionally delete Gpx1 in hepatocytes (Alb-Cre;Gpx1 lox/lox) and characterised mice fed chow, high-fat or choline-deficient amino-acid-defined (CDAA) diets. RESULTS: Chow-fed Alb-Cre;Gpx1 lox/lox mice did not exhibit any alterations in body composition or energy expenditure, but had improved insulin sensitivity and reduced fasting blood glucose. This was accompanied by decreased gluconeogenic and increased glycolytic gene expression as well as increased hepatic glycogen. Hepatic insulin receptor Y1163/Y1163 phosphorylation and Akt Ser-473 phosphorylation were increased in fasted chow-fed Alb-Cre;Gpx1 lox/lox mice, associated with increased H2O2 production and insulin signalling in isolated hepatocytes. The enhanced insulin signalling was accompanied by the increased oxidation of hepatic protein tyrosine phosphatases previously implicated in the attenuation of insulin signalling. High-fat-fed Alb-Cre;Gpx1 lox/lox mice did not exhibit alterations in weight gain or hepatosteatosis, but exhibited decreased hepatic inflammation, decreased gluconeogenic gene expression and increased insulin signalling in the liver. Alb-Cre;Gpx1 lox/lox mice fed a CDAA diet that promotes non-alcoholic steatohepatitis exhibited decreased hepatic lymphocytic infiltrates, inflammation and liver fibrosis. CONCLUSIONS/INTERPRETATION: Increased hepatocyte-derived H2O2 enhances hepatic insulin signalling, improves glucose control and protects mice from the development of non-alcoholic steatohepatitis.
Asunto(s)
Hígado Graso/metabolismo , Glucosa/metabolismo , Glutatión Peroxidasa/deficiencia , Glutatión Peroxidasa/metabolismo , Hígado/metabolismo , Enfermedad del Hígado Graso no Alcohólico/enzimología , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Alelos , Animales , Diabetes Mellitus Tipo 2/enzimología , Diabetes Mellitus Tipo 2/metabolismo , Hepatocitos/metabolismo , Peróxido de Hidrógeno/metabolismo , Resistencia a la Insulina/fisiología , Hígado/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Reacción en Cadena de la Polimerasa , Proteínas Tirosina Fosfatasas/genética , Proteínas Tirosina Fosfatasas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Glutatión Peroxidasa GPX1RESUMEN
AIMS/HYPOTHESIS: T cell protein tyrosine phosphatase (TCPTP, encoded by PTPN2) regulates cytokine-induced pancreatic beta cell apoptosis and may contribute to the pathogenesis of type 1 diabetes. However, the role of TCPTP in pancreatic endocrine function and insulin secretion remains largely unknown. METHODS: To investigate the endocrine role of pancreatic TCPTP we generated mice with pancreas Ptpn2/TCPTP deletion (panc-TCPTP KO). RESULTS: When fed regular chow, panc-TCPTP KO and control mice exhibited comparable glucose tolerance. However, when challenged with prolonged high fat feeding panc-TCPTP KO mice exhibited impaired glucose tolerance and attenuated glucose-stimulated insulin secretion (GSIS). The defect in GSIS was recapitulated in primary islets ex vivo and after TCPTP pharmacological inhibition or lentiviral-mediated TCPTP knockdown in the glucose-responsive MIN6 beta cells, consistent with this being cell autonomous. Reconstitution of TCPTP in knockdown cells reversed the defect in GSIS demonstrating that the defect was a direct consequence of TCPTP deficiency. The reduced insulin secretion in TCPTP knockdown MIN6 beta cells was associated with decreased insulin content and glucose sensing. Furthermore, TCPTP deficiency led to enhanced tyrosyl phosphorylation of signal transducer and activator of transcription 1 and 3 (STAT 1/3), and substrate trapping studies in MIN6 beta cells identified STAT 1/3 as TCPTP substrates. STAT3 pharmacological inhibition and small interfering RNA-mediated STAT3 knockdown in TCPTP deficient cells restored GSIS to control levels, indicating that the effects of TCPTP deficiency were mediated, at least in part, through enhanced STAT3 phosphorylation and signalling. CONCLUSIONS/INTERPRETATION: These studies identify a novel role for TCPTP in insulin secretion and uncover STAT3 as a physiologically relevant target for TCPTP in the endocrine pancreas.
Asunto(s)
Células Secretoras de Insulina/fisiología , Páncreas/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 2/genética , Animales , Células Cultivadas , Dieta Alta en Grasa , Femenino , Glucosa/metabolismo , Glucosa/farmacología , Intolerancia a la Glucosa/genética , Intolerancia a la Glucosa/metabolismo , Insulina/metabolismo , Secreción de Insulina , Células Secretoras de Insulina/metabolismo , Masculino , Ratones , Ratones Noqueados , Proteína Tirosina Fosfatasa no Receptora Tipo 2/metabolismo , Factor de Transcripción STAT3/metabolismoRESUMEN
Antigen cross-presentation by dendritic cells is crucial for priming cytotoxic CD8(+) T cells to invading pathogens and tumour antigens, as well as mediating peripheral tolerance to self-antigens. The protein tyrosine phosphatase N2 (PTPN2) attenuates T cell receptor (TCR) signalling and tunes CD8(+) T cell responses in vivo. In this study we have examined the role of PTPN2 in the maintenance of peripheral tolerance after the cross-presentation of pancreatic ß-cell antigens. The transfer of OVA-specific OT-I CD8(+) T cells (C57BL/6) into RIP-mOVA recipients expressing OVA in pancreatic ß-cells only results in islet destruction when OVA-specific CD4(+) T cells are co-transferred. Herein we report that PTPN2-deficient OT-I CD8(+) T cells transferred into RIP-mOVA recipients acquire CTL activity and result in ß cell destruction and the development of diabetes in the absence of CD4(+) help. These studies identify PTPN2 as a critical mediator of peripheral T cell tolerance limiting CD8(+) T cell responses after the cross-presentation of self-antigens. Our findings reveal a mechanism by which PTPN2 SNPs might convert a tolerogenic CD8(+) T cell response into one capable of causing the destruction of pancreatic ß-cells. Moreover, our results provide insight into potential approaches for enhancing T cell-mediated immunity and/or T cell adoptive tumour immunotherapy.
Asunto(s)
Presentación de Antígeno , Autoantígenos/inmunología , Linfocitos T CD8-positivos/inmunología , Tolerancia Inmunológica , Proteína Tirosina Fosfatasa no Receptora Tipo 2/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Traslado Adoptivo , Animales , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/inmunología , Autoantígenos/genética , Linfocitos T CD4-Positivos/inmunología , Células Secretoras de Insulina/inmunología , Ratones , Ratones Transgénicos , Neoplasias/genética , Neoplasias/inmunología , Neoplasias/terapia , Proteína Tirosina Fosfatasa no Receptora Tipo 2/genética , Receptores de Antígenos de Linfocitos T/genética , Transducción de Señal/genética , Transducción de Señal/inmunologíaRESUMEN
BACKGROUND: Acute pancreatitis (AP) is a common clinical problem whose incidence has been progressively increasing in recent years. Onset of the disease is trigged by intra-acinar cell activation of digestive enzyme zymogens that induce autodigestion, release of pro-inflammatory cytokines and acinar cell injury. T-cell protein tyrosine phosphatase (TCPTP) is implicated in inflammatory signaling but its significance in AP remains unclear. RESULTS: In this study we assessed the role of pancreatic TCPTP in cerulein-induced AP. TCPTP expression was increased at the protein and messenger RNA levels in the early phase of AP in mice and rats. To directly determine whether TCPTP may have a causal role in AP we generated mice with pancreatic TCPTP deletion (panc-TCPTP KO) by crossing TCPTP floxed mice with Pdx1-Cre transgenic mice. Amylase and lipase levels were lower in cerulein-treated panc-TCPTP KO mice compared with controls. In addition, pancreatic mRNA and serum concentrations of the inflammatory cytokines TNFα and IL-6 were lower in panc-TCPTP KO mice. At the molecular level, panc-TCPTP KO mice exhibited enhanced cerulein-induced STAT3 Tyr705 phosphorylation accompanied by a decreased cerulein-induced NF-κB inflammatory response, and decreased ER stress and cell death. CONCLUSION: These findings revealed a novel role for pancreatic TCPTP in the progression of cerulein-induced AP.
Asunto(s)
Pancreatitis Aguda Necrotizante/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 2/metabolismo , Amilasas/sangre , Animales , Ceruletida/toxicidad , Interleucina-6/sangre , Lipasa/sangre , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , FN-kappa B/metabolismo , Pancreatitis Aguda Necrotizante/inducido químicamente , Fosforilación , Proteína Tirosina Fosfatasa no Receptora Tipo 2/deficiencia , Proteína Tirosina Fosfatasa no Receptora Tipo 2/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Wistar , Factor de Transcripción STAT3/metabolismo , Factor de Necrosis Tumoral alfa/sangreRESUMEN
The CC-chemokine receptor 6 (CCR6) is expressed constitutively at an intermediate level on naïve B cells and is upregulated after activation on pregerminal center (GC) B cells. We hypothesized that it could be involved in the events leading to GC reaction and high-affinity antibody production, and therefore investigated the potential role of CCR6 in B-cell differentiation in vivo. After antigenic challenge of CCR6-/- mice with the T-cell-dependent antigen nitrophenyl-keyhole limpet hemocyanin (NP-KLH), GC B-cell development was found to be accelerated and the number of GC had increased significantly compared with control mice, but the antibodies produced by CCR6-/- B cells were on average of lower affinity. We conclude from these data that the CCR6/CCL20 axis has an important role in regulating the kinetics and efficiency of the GC reaction.
Asunto(s)
Linfocitos B/inmunología , Centro Germinal/inmunología , Receptores CCR6/metabolismo , Animales , Afinidad de Anticuerpos/genética , Formación de Anticuerpos/genética , Quimiocina CCL20/metabolismo , Regulación de la Expresión Génica , Centro Germinal/citología , Haptenos , Hemocianinas/inmunología , Inmunomodulación , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores CCR6/genética , Receptores CCR6/inmunología , Regulación hacia ArribaRESUMEN
During T cell development, the first step in creating a unique T cell receptor (TCR) is genetic recombination of the TCRß chain. The quality of the new TCRß is assessed at the ß-selection checkpoint. Most cells fail this checkpoint and die, but the coordination of fate at the ß-selection checkpoint is not yet understood. We shed new light on fate determination during ß-selection using a selective inhibitor of histone deacetylase 6, ACY1215. ACY1215 disrupted the ß-selection checkpoint. Characterising the basis for this disruption revealed a new, pivotal stage in ß-selection, bookended by up-regulation of TCR co-receptors, CD28 and CD2, respectively. Within this "DN3bPre" stage, CD5 and Lef1 are up-regulated to reflect pre-TCR signalling, and their expression correlates with proliferation. These findings suggest a refined model of ß-selection in which a coordinated increase in expression of pre-TCR, CD28, CD5 and Lef1 allows for modulating TCR signalling strength and culminates in the expression of CD2 to enable exit from the ß-selection checkpoint.
Asunto(s)
Antígenos CD28 , Receptores de Antígenos de Linfocitos T alfa-beta , Antígenos CD28/genética , Antígenos CD28/metabolismo , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Histonas/metabolismo , Histona Desacetilasa 6/metabolismo , Linfocitos T/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismoRESUMEN
The inhibition of protein tyrosine phosphatases (PTPs), such as PTP1B and PTPN2 that function as intracellular checkpoints, has emerged as an exciting new approach for bolstering T cell anti-tumor immunity to combat cancer. ABBV-CLS-484 is a dual PTP1B and PTPN2 inhibitor currently in clinical trials for solid tumors. Here we have explored the therapeutic potential of targeting PTP1B and PTPN2 with a related small molecule inhibitor, Compound 182. We demonstrate that Compound 182 is a highly potent and selective active site competitive inhibitor of PTP1B and PTPN2 that enhances antigen-induced T cell activation and expansion ex vivo and represses the growth of syngeneic tumors in C57BL/6 mice without promoting overt immune-related toxicities. Compound 182 repressed the growth of immunogenic MC38 colorectal and AT3-OVA mammary tumors as well as immunologically cold AT3 mammary tumors that are largely devoid of T cells. Treatment with Compound 182 increased both the infiltration and activation of T cells, as well as the recruitment of NK cells and B cells that promote anti-tumor immunity. The enhanced anti-tumor immunity in immunogenic AT3-OVA tumors could be ascribed largely to the inhibition of PTP1B/PTPN2 in T cells, whereas in cold AT3 tumors, Compound 182 elicited both direct effects on tumor cells and T cells to facilitate T cell recruitment and thereon activation. Importantly, treatment with Compound 182 rendered otherwise resistant AT3 tumors sensitive to anti-PD1 therapy. Our findings establish the potential for small molecule active site inhibitors of PTP1B and PTPN2 to enhance anti-tumor immunity and combat cancer.
RESUMEN
The inhibition of protein tyrosine phosphatases 1B (PTP1B) and N2 (PTPN2) has emerged as an exciting approach for bolstering T cell anti-tumor immunity. ABBV-CLS-484 is a PTP1B/PTPN2 inhibitor in clinical trials for solid tumors. Here we have explored the therapeutic potential of a related small-molecule-inhibitor, Compound-182. We demonstrate that Compound-182 is a highly potent and selective active site competitive inhibitor of PTP1B and PTPN2 that enhances T cell recruitment and activation and represses the growth of tumors in mice, without promoting overt immune-related toxicities. The enhanced anti-tumor immunity in immunogenic tumors can be ascribed to the inhibition of PTP1B/PTPN2 in T cells, whereas in cold tumors, Compound-182 elicited direct effects on both tumor cells and T cells. Importantly, treatment with Compound-182 rendered otherwise resistant tumors sensitive to α-PD-1 therapy. Our findings establish the potential for small molecule inhibitors of PTP1B and PTPN2 to enhance anti-tumor immunity and combat cancer.
Asunto(s)
Neoplasias , Proteína Tirosina Fosfatasa no Receptora Tipo 2 , Ratones , Animales , Proteína Tirosina Fosfatasa no Receptora Tipo 2/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 2/metabolismo , Monoéster Fosfórico Hidrolasas , Neoplasias/tratamiento farmacológico , Proteína Tirosina Fosfatasa no Receptora Tipo 1/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 1/metabolismo , Linfocitos T/metabolismo , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/químicaRESUMEN
Nonalcoholic fatty liver disease (NAFLD) is prevalent in the majority of individuals with obesity, but in a subset of these individuals, it progresses to nonalcoholic steatohepatitis (0NASH) and fibrosis. The mechanisms that prevent NASH and fibrosis in the majority of patients with NAFLD remain unclear. Here, we report that NAD(P)H oxidase 4 (NOX4) and nuclear factor erythroid 2-related factor 2 (NFE2L2) were elevated in hepatocytes early in disease progression to prevent NASH and fibrosis. Mitochondria-derived ROS activated NFE2L2 to induce the expression of NOX4, which in turn generated H2O2 to exacerbate the NFE2L2 antioxidant defense response. The deletion or inhibition of NOX4 in hepatocytes decreased ROS and attenuated antioxidant defense to promote mitochondrial oxidative stress, damage proteins and lipids, diminish insulin signaling, and promote cell death upon oxidant challenge. Hepatocyte NOX4 deletion in high-fat diet-fed obese mice, which otherwise develop steatosis, but not NASH, resulted in hepatic oxidative damage, inflammation, and T cell recruitment to drive NASH and fibrosis, whereas NOX4 overexpression tempered the development of NASH and fibrosis in mice fed a NASH-promoting diet. Thus, mitochondria- and NOX4-derived ROS function in concert to drive a NFE2L2 antioxidant defense response to attenuate oxidative liver damage and progression to NASH and fibrosis in obesity.