RESUMO
AIMS: Inflammation was closely associated with diabetes-related endothelial dysfunction. C1q/tumor necrosis factor-related protein 3 (CTRP3) is a member of the CTRP family and can provide cardioprotection in many cardiovascular diseases via suppressing the production of inflammatory factors. However, the role of CTRP3 in high glucose- (HG-) related endothelial dysfunction remains unclear. This study evaluates the effects of CTRP3 on HG-induced cell inflammation and apoptosis. MATERIALS AND METHODS: To prevent high glucose-induced cell injury, human umbilical vein endothelial cells (HUVECs) were pretreated with recombinant CTRP3 for 1 hour followed by normal glucose (5.5 mmol/l) or high glucose (33 mmol/l) treatment. After that, cell apoptosis and inflammatory factors were determined. RESULTS: Our results demonstrated that CTRP3 mRNA and protein expression were significantly decreased after HG exposure in HUVECs. Recombinant human CTRP3 inhibited HG-induced accumulation of inflammatory factors and cell loss in HUVECs. CTRP3 treatment also increased the phosphorylation levels of protein kinase B (AKT/PKB) and the mammalian target of rapamycin (mTOR) in HUVECs. CTRP3 lost its inhibitory effects on HG-induced cell inflammation and apoptosis after AKT inhibition. Knockdown of endogenous CTRP3 in HUVECs resulted in increased inflammation and decreased cell viability in vitro. CONCLUSIONS: Taken together, these findings indicated that CTRP3 treatment blocked the accumulation of inflammatory factors and cell loss in HUVECs after HG exposure through the activation of AKT-mTOR signaling pathway. Thus, CTRP3 may be a potential therapeutic drug for the prevention of diabetes-related endothelial dysfunction.
Assuntos
Citoproteção , Glucose/toxicidade , Células Endoteliais da Veia Umbilical Humana/patologia , Substâncias Protetoras/metabolismo , Fatores de Necrose Tumoral/metabolismo , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Deleção de Genes , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Mediadores da Inflamação/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Fatores de Necrose Tumoral/deficiênciaRESUMO
Regulatory T cells (Tregs) are closely related to TH17 cells and use aspects of the TH17-differentiation program for optimal immune regulation. In several chronic inflammatory human diseases, Tregs express IL-17A, suggesting that dysregulation of TH17-associated pathways in Tregs may result in either loss of suppressive function and/or conversion into pathogenic cells. The pathways that regulate the TH17 program in Tregs are poorly understood. We have identified two TNF receptor superfamily (TNFRSF) members, CD27 and OX40, that are preferentially expressed by skin-resident Tregs Both CD27 and OX40 signaling suppressed the expression of TH17-associated genes from Tregs in a cell-intrinsic manner in vitro and in vivo. However, only OX40 played a nonredundant role in promoting Treg accumulation. Tregs that lacked both CD27 and OX40 were defective in controlling skin inflammation and expressed high levels of IL-17A, as well as the master TH17 transcription factor, RORγt. Last, we found that CD27 expression was inversely correlated with Treg IL-17 production in skin of patients with psoriasis and hidradenitis suppurativa. Together, our results suggest that TNFRSF members play both redundant and distinct roles in regulating Treg plasticity in tissues.
Assuntos
Glicoproteínas de Membrana/imunologia , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Fatores de Necrose Tumoral/imunologia , Animais , Diferenciação Celular/imunologia , Glicoproteínas de Membrana/deficiência , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ligante OX40 , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/deficiênciaRESUMO
Innate immune responses that are crucial for control of infection are often targeted by microbial pathogens. Blockade of NF-κB and MAPK signaling by the Yersinia virulence factor YopJ inhibits cytokine production by innate immune cells but also triggers cell death. This cell death requires RIPK1 kinase activity and caspase-8, which are engaged by TLR4 and the adaptor protein TRIF. Nevertheless, TLR4- and TRIF-deficient cells undergo significant apoptosis, implicating TLR4/TRIF-independent pathways in the death of Yersinia-infected cells. In this article, we report a key role for TNF/TNFR1 in Yersinia-induced cell death of murine macrophages, which occurs despite the blockade of NF-κB and MAPK signaling imposed by Yersinia on infected cells. Intriguingly, direct analysis of YopJ injection revealed a heterogeneous population of injection-high and injection-low cells, and demonstrated that TNF expression came from the injection-low population. Moreover, TNF production by this subpopulation was necessary for maximal apoptosis in the population of highly injected cells, and TNFR-deficient mice displayed enhanced susceptibility to Yersinia infection. These data demonstrate an important role for collaboration between TNF and pattern recognition receptor signals in promoting maximal apoptosis during bacterial infection, and demonstrate that heterogeneity in virulence factor injection and cellular responses play an important role in promoting anti-Yersinia immune defense.
Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Apoptose , Macrófagos/microbiologia , Macrófagos/fisiologia , Fatores de Necrose Tumoral/metabolismo , Yersiniose/imunologia , Yersinia pseudotuberculosis/patogenicidade , Animais , Proteínas de Bactérias/genética , Caspase 1/metabolismo , Morte Celular , Imunidade Inata , L-Lactato Desidrogenase/metabolismo , Camundongos , Plasmídeos/genética , Transdução de Sinais , Receptor 4 Toll-Like/imunologia , Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/imunologia , Yersinia pseudotuberculosis/imunologiaRESUMO
Tumour necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factor-inducible 14 (Fn14) have been associated with liver regeneration in vivo. To further investigate the role of this pathway we examined their expression in human fibrotic liver disease and the effect of pathway deficiency in a murine model of liver fibrosis. The expression of Fn14 and TWEAK in normal and diseased human and mouse liver tissue and primary human hepatic stellate cells (HSCs) were investigated by qPCR, western blotting and immunohistochemistry. In addition, the levels of Fn14 in HSCs following pro-fibrogenic and pro-inflammatory stimuli were assessed and the effects of exogenous TWEAK on HSCs proliferation and activation were studied in vitro. Carbon tetrachloride (CCl4 ) was used to induce acute and chronic liver injury in TWEAK KO mice. Elevated expression of both Fn14 and TWEAK were detected in acute and chronic human liver injury, and co-localized with markers of activated HSCs. Fn14 levels were low in quiescent HSCs but were significantly induced in activated HSCs, which could be further enhanced with the profibrogenic cytokine TGFß in vitro. Stimulation with recombinant TWEAK induced proliferation but not further HSCs activation. Fn14 gene expression was also significantly up-regulated in CCl4 models of hepatic injury whereas TWEAK KO mice showed reduced levels of liver fibrosis following chronic CCl4 injury. In conclusion, TWEAK/Fn14 interaction leads to the progression of fibrotic liver disease via direct modulation of HSCs proliferation, making it a potential therapeutic target for liver fibrosis.
Assuntos
Células Estreladas do Fígado/patologia , Cirrose Hepática/etiologia , Receptores do Fator de Necrose Tumoral/metabolismo , Fatores de Necrose Tumoral/deficiência , Actinas/metabolismo , Animais , Tetracloreto de Carbono/toxicidade , Proliferação de Células , Doença Hepática Induzida por Substâncias e Drogas , Doença Hepática Crônica Induzida por Substâncias e Drogas , Citocina TWEAK , Progressão da Doença , Fibroblastos/metabolismo , Humanos , Cirrose Hepática/patologia , Masculino , Camundongos Knockout , RNA Mensageiro/metabolismo , Fatores de Transcrição SOX9/metabolismo , Receptor de TWEAK , Fatores de Necrose Tumoral/metabolismo , Fatores de Necrose Tumoral/farmacologia , Regulação para Cima/fisiologiaRESUMO
BACKGROUND: To evaluate the inflammatory axis mediated by tumour necrosis factor-like weak inducer of apoptosis (TWEAK) and its scavenger receptor CD163 during pregnancy and their influence on insulin sensitivity in normal pregnancy and in gestational diabetes mellitus (GDM). MATERIALS AND METHODS: One hundred and thirty seven women with one singleton pregnancy, 71 with normal glucose tolerance (NGT) and 66 with GDM were studied. Glucose metabolism was assessed by oral glucose tolerance test. Serum concentrations of soluble TWEAK (sTWEAK) and CD163 (sCD163) and insulin resistance (HOMA-IR index) were determined in maternal blood drawn at recruitment, in the early third trimester. Offspring weight and height were assessed at birth. RESULTS: Women with GDM had lower circulating sTWEAK concentrations than control NGT group (237·8 (192·1-301·0) pg/mL vs. 277·2 (206·4-355·7) pg/mL; P = 0·013). sTWEAK was negatively associated with the presence of GDM (r = -0·212; P = 0·013), HOMA-IR index (r = -0·197; P = 0·021) and ponderal index of the newborn (r = -0·196; P = 0·025), but positively with HDL cholesterol (r = 0·283; P = 0·001). In multiple regression analysis, sTWEAK concentration emerged as one of the main predictors of insulin resistance, along with BMI, triglycerides and low concentrations of HDL cholesterol (R(2) = 0·486; P < 0·001). No relationship was found between HOMA-IR index and sCD163 or sCD163/sTWEAK ratio. CONCLUSIONS: sTWEAK concentrations are lower in patients with GDM compared with healthy pregnant women, and low concentrations of sTWEAK are associated with insulin resistance. These findings suggest that insulin resistance during pregnancy is closely linked to inflammatory imbalance and sTWEAK may represent a new candidate associated with GDM.
Assuntos
Diabetes Gestacional/etiologia , Fatores de Necrose Tumoral/deficiência , Adulto , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Estudos de Casos e Controles , Citocina TWEAK , Feminino , Humanos , Resistência à Insulina/fisiologia , Gravidez , Estudos Prospectivos , Receptores de Superfície Celular/metabolismo , Análise de RegressãoRESUMO
Satellite cell self-renewal is an essential process to maintaining the robustness of skeletal muscle regenerative capacity. However, extrinsic factors that regulate self-renewal of satellite cells are not well understood. Here, we demonstrate that TWEAK cytokine reduces the proportion of Pax7(+)/MyoD(-) cells (an index of self-renewal) on myofiber explants and represses multiple components of Notch signaling in satellite cell cultures. The number of Pax7(+) cells is significantly increased in skeletal muscle of TWEAK knock-out (KO) mice compared with wild-type in response to injury. Furthermore, Notch signaling is significantly elevated in cultured satellite cells and in regenerating myofibers of TWEAK-KO mice. Forced activation of Notch signaling through overexpression of the Notch1 intracellular domain (N1ICD) rescued the TWEAK-mediated inhibition of satellite cell self-renewal. TWEAK also activates the NF-κB transcription factor in satellite cells and inhibition of NF-κB significantly improved the number of Pax7(+) cells in TWEAK-treated cultures. Furthermore, our results demonstrate that a reciprocal interaction between NF-κB and Notch signaling governs the inhibitory effect of TWEAK on satellite cell self-renewal. Collectively, our study demonstrates that TWEAK suppresses satellite cell self-renewal through activating NF-κB and repressing Notch signaling.
Assuntos
NF-kappa B/metabolismo , Receptor Notch1/metabolismo , Células Satélites de Músculo Esquelético/citologia , Células Satélites de Músculo Esquelético/metabolismo , Fatores de Necrose Tumoral/metabolismo , Animais , Apoptose/fisiologia , Proliferação de Células , Células Cultivadas , Citocina TWEAK , Mediadores da Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína MyoD/genética , Proteína MyoD/metabolismo , NF-kappa B/genética , Fator de Transcrição PAX7/genética , Fator de Transcrição PAX7/metabolismo , Estrutura Terciária de Proteína , Receptor Notch1/química , Receptor Notch1/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Regeneração/genética , Regeneração/fisiologia , Transdução de Sinais , Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/genéticaRESUMO
BACKGROUND: Cerebral cortical neurons have a high vulnerability to the harmful effects of hypoxia. However, the brain has the ability to detect and accommodate to hypoxic conditions. This phenomenon, known as preconditioning, is a natural adaptive process highly preserved among species whereby exposure to sub-lethal hypoxia promotes the acquisition of tolerance to a subsequent lethal hypoxic injury. The cytokine tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factor-inducible 14 (Fn14) are found in neurons and their expression is induced by exposure to sub-lethal hypoxia. Accordingly, in this work we tested the hypothesis that the interaction between TWEAK and Fn14 induces tolerance to lethal hypoxic and ischemic conditions. METHODS: Here we used in vitro and in vivo models of hypoxic and ischemic preconditioning, an animal model of transient middle cerebral artery occlusion and mice and neurons genetically deficient in TWEAK, Fn14, or tumor necrosis factor alpha (TNF-α) to investigate whether treatment with recombinant TWEAK or an increase in the expression of endogenous TWEAK renders neurons tolerant to lethal hypoxia. We used enzyme-linked immunosorbent assay to study the effect of TWEAK on the expression of neuronal TNF-α, Western blot analysis to investigate whether the effect of TWEAK was mediated by activation of mitogen-activated protein kinases and immunohistochemical techniques and quantitative real-time polymerase chain reaction analysis to study the effect of TWEAK on apoptotic cell death. RESULTS: We found that either treatment with recombinant TWEAK or an increase in the expression of TWEAK and Fn14 induce hypoxic and ischemic tolerance in vivo and in vitro. This protective effect is mediated by neuronal TNF-α and activation of the extracellular signal-regulated kinases 1 and 2 pathway via phosphorylation and inactivation of the B-cell lymphoma 2-associated death promoter protein. CONCLUSIONS: Our work indicate that the interaction between TWEAK and Fn14 triggers the activation of a cell signaling pathway that results in the induction of tolerance to lethal hypoxia and ischemia. These data indicate that TWEAK may be a potential therapeutic strategy to protect the brain from the devastating effects of an ischemic injury.
Assuntos
Apoptose/efeitos dos fármacos , Infarto da Artéria Cerebral Média/patologia , Precondicionamento Isquêmico/métodos , Fármacos Neuroprotetores/farmacologia , Receptores do Fator de Necrose Tumoral/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Fatores de Necrose Tumoral/farmacologia , Animais , Apoptose/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Células Cultivadas , Córtex Cerebral/citologia , Citocina TWEAK , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Glucose/deficiência , Hipóxia/tratamento farmacológico , Marcação In Situ das Extremidades Cortadas , Técnicas In Vitro , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Receptores do Fator de Necrose Tumoral/deficiência , Receptor de TWEAK , Fatores de Tempo , Fator de Necrose Tumoral alfa/deficiência , Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/metabolismoRESUMO
Intestinal immune homeostasis depends on a tightly regulated cross talk between commensal bacteria, mucosal immune cells and intestinal epithelial cells (IECs). Epithelial barrier disruption is considered to be a potential cause of inflammatory bowel disease; however, the mechanisms regulating intestinal epithelial integrity are poorly understood. Here we show that mice with IEC-specific knockout of FADD (FADD(IEC-KO)), an adaptor protein required for death-receptor-induced apoptosis, spontaneously developed epithelial cell necrosis, loss of Paneth cells, enteritis and severe erosive colitis. Genetic deficiency in RIP3, a critical regulator of programmed necrosis, prevented the development of spontaneous pathology in both the small intestine and colon of FADD(IEC-KO) mice, demonstrating that intestinal inflammation is triggered by RIP3-dependent death of FADD-deficient IECs. Epithelial-specific inhibition of CYLD, a deubiquitinase that regulates cellular necrosis, prevented colitis development in FADD(IEC-KO) but not in NEMO(IEC-KO) mice, showing that different mechanisms mediated death of colonic epithelial cells in these two models. In FADD(IEC-KO) mice, TNF deficiency ameliorated colon inflammation, whereas MYD88 deficiency and also elimination of the microbiota prevented colon inflammation, indicating that bacteria-mediated Toll-like-receptor signalling drives colitis by inducing the expression of TNF and other cytokines. However, neither CYLD, TNF or MYD88 deficiency nor elimination of the microbiota could prevent Paneth cell loss and enteritis in FADD(IEC-KO) mice, showing that different mechanisms drive RIP3-dependent necrosis of FADD-deficient IECs in the small and large bowel. Therefore, by inhibiting RIP3-mediated IEC necrosis, FADD preserves epithelial barrier integrity and antibacterial defence, maintains homeostasis and prevents chronic intestinal inflammation. Collectively, these results show that mechanisms preventing RIP3-mediated epithelial cell death are critical for the maintenance of intestinal homeostasis and indicate that programmed necrosis of IECs might be implicated in the pathogenesis of inflammatory bowel disease, in which Paneth cell and barrier defects are thought to contribute to intestinal inflammation.
Assuntos
Colite/patologia , Colo/patologia , Enterite/patologia , Células Epiteliais/patologia , Proteína de Domínio de Morte Associada a Fas/metabolismo , Proteína Serina-Treonina Quinases de Interação com Receptores/antagonistas & inibidores , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Animais , Apoptose , Doença Crônica , Colite/enzimologia , Colite/metabolismo , Colo/enzimologia , Colo/metabolismo , Cisteína Endopeptidases/metabolismo , Enzima Desubiquitinante CYLD , Enterite/enzimologia , Enterite/metabolismo , Células Epiteliais/enzimologia , Células Epiteliais/metabolismo , Proteína de Domínio de Morte Associada a Fas/deficiência , Doenças Inflamatórias Intestinais/enzimologia , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/patologia , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Metagenoma/fisiologia , Camundongos , Fator 88 de Diferenciação Mieloide/deficiência , Fator 88 de Diferenciação Mieloide/metabolismo , Necrose , Celulas de Paneth/patologia , Transdução de Sinais , Fatores de Necrose Tumoral/deficiênciaRESUMO
Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor Fibroblast growth factor-inducible 14 (Fn14) are expressed in neurons. Here we demonstrate that TWEAK induces a dose-dependent increase in neuronal death and that this effect is independent of tumor necrosis factor alpha (TNF-α) and mediated by nuclear factor-kappa B (NF-κB) pathway activation. Incubation with TWEAK induces apoptotic cell death in wild-type (Wt) but not in Fn14 deficient (Fn14(-/-)) neurons. Intracerebral injection of TWEAK induces accumulation of poly(ADP-ribose) polymers (PAR) in Wt but not in Fn14(-/-) mice. Exposure to oxygen-glucose deprivation (OGD) conditions increases TWEAK and Fn14 mRNA expression in Wt neurons, and decreases cell survival in Wt but not in Fn14(-/-) or TWEAK deficient (TWEAK(-/-)) neurons. Experimental middle cerebral artery occlusion (MCAO) increases the expression of TWEAK and Fn14 mRNA and active caspase-3, and the cleavage of poly(ADP-ribose) polymerase-1 (PARP-1) with accumulation of PAR in the ischemic area in Wt but not Fn14(-/-) mice. Together, these results suggest a model where in response to hypoxia/ischemia the interaction between TWEAK and Fn14 in neurons induces PARP-1 activation with accumulation of PAR polymers and cell death via NF-κB pathway activation. This is a novel pathway for hypoxia/ischemia-induced TWEAK-mediated cell death and a potential therapeutic target for ischemic stroke.
Assuntos
Infarto da Artéria Cerebral Média/enzimologia , Infarto da Artéria Cerebral Média/patologia , Neurônios/fisiologia , Poli(ADP-Ribose) Polimerases/metabolismo , Animais , Morte Celular/efeitos dos fármacos , Morte Celular/genética , Células Cultivadas , Córtex Cerebral/citologia , Citocina TWEAK , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Embrião de Mamíferos , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Glucose/deficiência , Peróxido de Hidrogênio/farmacologia , Hipóxia/patologia , Infarto da Artéria Cerebral Média/fisiopatologia , Camundongos , Camundongos Knockout , Neurônios/efeitos dos fármacos , Oxidantes/farmacologia , Poli(ADP-Ribose) Polimerase-1 , Receptores do Fator de Necrose Tumoral/deficiência , Receptores do Fator de Necrose Tumoral/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Receptor de TWEAK , Fator de Necrose Tumoral alfa/farmacologia , Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/farmacologiaRESUMO
Skeletal muscle atrophy occurs in a variety of clinical settings, including cachexia, disuse, and denervation. Inflammatory cytokines have been shown to be mediators of cancer cachexia; however, the role of cytokines in denervation- and immobilization-induced skeletal muscle loss remains unknown. In this study, we demonstrate that a single cytokine, TNF-like weak inducer of apoptosis (TWEAK), mediates skeletal muscle atrophy that occurs under denervation conditions. Transgenic expression of TWEAK induces atrophy, fibrosis, fiber-type switching, and the degradation of muscle proteins. Importantly, genetic ablation of TWEAK decreases the loss of muscle proteins and spared fiber cross-sectional area, muscle mass, and strength after denervation. Expression of the TWEAK receptor Fn14 (fibroblast growth factor-inducible receptor 14) and not the cytokine is significantly increased in muscle upon denervation, demonstrating an unexpected inside-out signaling pathway; the receptor up-regulation allows for TWEAK activation of nuclear factor kappaB, causing an increase in the expression of the E3 ubiquitin ligase MuRF1. This study reveals a novel mediator of skeletal muscle atrophy and indicates that the TWEAK-Fn14 system is an important target for preventing skeletal muscle wasting.
Assuntos
Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Atrofia Muscular/metabolismo , Receptores do Fator de Necrose Tumoral/metabolismo , Fatores de Necrose Tumoral/metabolismo , Animais , Citocina TWEAK , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Denervação Muscular , Músculo Esquelético/inervação , Atrofia Muscular/patologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Receptor de TWEAK , Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/genéticaRESUMO
A T cell costimulatory molecule, OX40, contributes to T cell expansion, survival, and cytokine production. Although several roles for OX40 in CD8(+) T cell responses to tumors and viral infection have been shown, the precise function of these signals in the generation of memory CD8(+) T cells remains to be elucidated. To address this, we examined the generation and maintenance of memory CD8(+) T cells during infection with Listeria monocytogenes in the presence and absence of OX40 signaling. We used the expression of killer cell lectin-like receptor G1 (KLRG1), a recently reported marker, to distinguish between short-lived effector and memory precursor effector T cells (MPECs). Although OX40 was dispensable for the generation of effector T cells in general, the lack of OX40 signals significantly reduced the number and proportion of KLRG1(low) MPECs, and, subsequently, markedly impaired the generation of memory CD8(+) T cells. Moreover, memory T cells that were generated in the absence of OX40 signals in a host animal did not show self-renewal in a second host, suggesting that OX40 is important for the maintenance of memory T cells. Additional experiments making use of an inhibitory mAb against the OX40 ligand demonstrated that OX40 signals are essential during priming, not only for the survival of KLRG1(low) MPECs, but also for their self-renewing ability, both of which contribute to the homeostasis of memory CD8(+) T cells.
Assuntos
Adjuvantes Imunológicos/fisiologia , Linfócitos T CD8-Positivos/imunologia , Memória Imunológica , Ativação Linfocitária/imunologia , Receptores OX40/fisiologia , Transdução de Sinais/imunologia , Doença Aguda , Animais , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/microbiologia , Células Cultivadas , Técnicas de Cocultura , Modelos Animais de Doenças , Feminino , Memória Imunológica/genética , Lectinas Tipo C/antagonistas & inibidores , Lectinas Tipo C/fisiologia , Listeria monocytogenes/genética , Listeria monocytogenes/imunologia , Listeriose/imunologia , Listeriose/metabolismo , Ativação Linfocitária/genética , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Ligante OX40 , Receptores Imunológicos , Receptores OX40/deficiência , Receptores OX40/genética , Transdução de Sinais/genética , Células-Tronco/imunologia , Células-Tronco/metabolismo , Células-Tronco/microbiologia , Transativadores/antagonistas & inibidores , Transativadores/fisiologia , Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/genéticaRESUMO
Leukemia inhibitory factor (LIF) is a proinflammatory cytokine mediating a variety of central nervous system (CNS) responses to inflammatory stimuli. During lipopolysaccharide (LPS)-induced inflammation, blood concentrations of LIF increase, correlating with lethality of sepsis. Circulating LIF crosses the blood-brain barrier (BBB) by a saturable transport system. Here we determine how this transport system is regulated in neuroinflammation. Using transport assays that quantify the influx rate and volume of distribution of LIF in mice, we show that LPS facilitated the permeation of LIF from the blood to the brain without compromising the paracellular permeability of the BBB as determined by coadministration of fluorescein. Concurrently, gp130 (shared by the interleukin-6 family of cytokines), but not gp190 (the specific receptor for LIF) or cilliary neutrophic factor (CNTF-Ralpha, a unique receptor for cilliary neurotrophic factor that also uses gp130 and gp190), showed increased levels of mRNA and protein expression in cerebral microvessels from the LPS-treated mice. The upregulation of gp130 by LPS was at least partially mediated by vascular tumor necrosis factor receptor (TNFR)1 and TNFR2. This was shown by elevated TNFR1 and TNFR2 mRNA and protein in cerebral microvessels after LPS and by the absence of the LPS effect on gp130 in knockout mice lacking these receptors. The results show that neuroinflammation by LPS induces endothelial signaling and enhances cytokine transport across the BBB.
Assuntos
Barreira Hematoencefálica/metabolismo , Permeabilidade Capilar , Fator Inibidor de Leucemia/metabolismo , Sepse/metabolismo , Fatores de Necrose Tumoral/metabolismo , Animais , Subunidade alfa do Receptor do Fator Neutrófico Ciliar/genética , Subunidade alfa do Receptor do Fator Neutrófico Ciliar/metabolismo , Receptor gp130 de Citocina/genética , Receptor gp130 de Citocina/metabolismo , Modelos Animais de Doenças , Fluoresceína/metabolismo , Corantes Fluorescentes/metabolismo , Fator Inibidor de Leucemia/sangue , Lipopolissacarídeos , Masculino , Camundongos , Camundongos Knockout , Microcirculação/metabolismo , RNA Mensageiro/metabolismo , Receptores de OSM-LIF/genética , Receptores de OSM-LIF/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Receptores Tipo II do Fator de Necrose Tumoral/genética , Receptores Tipo II do Fator de Necrose Tumoral/metabolismo , Sepse/induzido quimicamente , Fatores de Tempo , Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/genéticaRESUMO
Tumors elicit antitumor immune responses, but over time they evolve and can escape immune control through various mechanisms, including the loss of the antigen to which the response is directed. The escape of antigen-loss variants (ALVs) is a major obstacle to T cell-based immunotherapy for cancer. However, cancers can be cured if both the number of CTLs and the expression of antigen are high enough to allow targeting of not only tumor cells, but also the tumor stroma. Here, we showed that IFN-gamma and TNF produced by CTLs were crucial for the elimination of established mouse tumors, including ALVs. In addition, both BM- and non-BM-derived stromal cells were required to express TNF receptors and IFN-gamma receptors for the elimination of ALVs. Although IFN-gamma and TNF were not required by CTLs for perforin-mediated killing of antigen-expressing tumor cells, the strong inference is that tumor antigen-specific CTLs must secrete IFN-gamma and TNF for destruction of tumor stroma. Therefore, bystander killing of ALVs may result from IFN-gamma and TNF acting on tumor stroma.
Assuntos
Antígenos/imunologia , Efeito Espectador/imunologia , Interferon gama/biossíntese , Neoplasias/imunologia , Neoplasias/metabolismo , Fatores de Necrose Tumoral/biossíntese , Transferência Adotiva , Animais , Linhagem Celular Tumoral , Interferon gama/deficiência , Interferon gama/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transplante de Neoplasias , Neoplasias/patologia , Receptores de Interferon/imunologia , Receptores do Fator de Necrose Tumoral/imunologia , Células Estromais/imunologia , Células Estromais/metabolismo , Linfócitos T/imunologia , Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/genéticaRESUMO
Inflammatory cytokines have been implicated in the pathology of multiple neurologic diseases, including multiple sclerosis. We examined the role of the TNF family member TWEAK in neuroinflammation. Cuprizone-fed mice undergo neuroinflammation and demyelination in the brain, but upon removal of cuprizone from the diet, inflammation is resolved and remyelination occurs. Using this model, we demonstrate that mice lacking TWEAK exhibit a significant delay in demyelination and microglial infiltration. During remyelination, mice lacking the TWEAK gene demonstrate only a marginal delay in remyelination. Thus, this study identifies a primary role of TWEAK in promoting neuroinflammation and exacerbating demyelination during cuprizone-induced damage.
Assuntos
Doenças Desmielinizantes/fisiopatologia , Encefalite/fisiopatologia , Fatores de Necrose Tumoral/fisiologia , Animais , Astrócitos/metabolismo , Astrócitos/patologia , Quelantes/toxicidade , Cobre , Cuprizona/toxicidade , Citocina TWEAK , Doenças Desmielinizantes/induzido quimicamente , Método Duplo-Cego , Encefalite/induzido quimicamente , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microglia/metabolismo , Microglia/patologia , Bainha de Mielina/fisiologia , Oligodendroglia/metabolismo , Oligodendroglia/patologia , RNA Mensageiro/biossíntese , Receptores do Fator de Necrose Tumoral/fisiologia , Receptor de TWEAK , Fatores de Necrose Tumoral/biossíntese , Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/genéticaRESUMO
Nerve growth factor (NGF) has an important role in regulating sympathetic neuron survival and target field innervation during development. Here we show that glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR), a member of the TNF superfamily, and its ligand (GITRL) are co-expressed in mouse sympathetic neurons when their axons are innervating their targets under the influence of target-derived NGF. In culture, GITRL enhanced NGF-promoted neurite growth from neonatal sympathetic neurons, and preventing GITR-GITRL interaction in these neurons or knocking down GITR inhibited NGF-promoted neurite growth without affecting neuronal survival. Tnfrsf18(-/-) (Gitr) neonates have reduced sympathetic innervation density in vivo compared with Gitr(+/+) littermates. GITR activation is required for the phosphorylation of extracellular signal-regulated kinases 1 and 2 by NGF that is necessary for neurite growth. Our results reveal a previously unknown signaling loop in developing sympathetic neurons that is crucial for NGF-dependent axon growth and target innervation.
Assuntos
Axônios/efeitos dos fármacos , Proteína Relacionada a TNFR Induzida por Glucocorticoide/fisiologia , Fator de Crescimento Neural/farmacologia , Neurônios/citologia , Transdução de Sinais/fisiologia , Fatores de Necrose Tumoral/metabolismo , Fatores Etários , Análise de Variância , Animais , Animais Recém-Nascidos , Células Cultivadas , Embrião de Mamíferos , Fluoresceínas/metabolismo , Proteína Relacionada a TNFR Induzida por Glucocorticoide/deficiência , Proteínas Luminescentes/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Neurônios/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Gânglio Cervical Superior/citologia , Fatores de Necrose Tumoral/deficiênciaRESUMO
Although corneal transplantation is one of the most common tissue transplantations and is known to have a high graft acceptance rate, occasional corneal graft rejection remains a cause of blindness. OX40, a member of the TNF receptor superfamily, is expressed on activated T cells, and transmits a costimulatory signal by binding to OX40 ligand (OX40L) expressed on several cells with antigen-presenting functions. Using a blocking monoclonal antibody (mAb) against murine OX40L, we investigated the role of OX40 in a murine model of corneal transplantation. C3H/He mouse corneas were transplanted to BALB/c mice orthotopically. Administration of anti-OX40L mAb significantly reduced allograft rejection, and increased graft survival rate to 40% at 8 weeks after transplantation, while all corneas were rejected within 5 weeks in control IgG-treated mice. Similar reduced rejection was observed when wild-type donor corneas were transplanted to OX40L-deficient recipients. In vitro study revealed that the anti-OX40L mAb treatment reduced proliferative response and IFN-gamma production of draining lymph node cells in response to stimulation with donor alloantigen. These results demonstrate that OX40L blockade is effective for prolongation of corneal allograft survival by inhibiting recipient T cell activation.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Transplante de Córnea , Rejeição de Enxerto/prevenção & controle , Sobrevivência de Enxerto/efeitos dos fármacos , Glicoproteínas de Membrana/antagonistas & inibidores , Inibidores do Fator de Necrose Tumoral , Animais , Anticorpos Monoclonais/imunologia , Avaliação Pré-Clínica de Medicamentos , Proteínas do Olho/imunologia , Interferon gama/biossíntese , Interleucina-10/biossíntese , Isoantígenos/imunologia , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Knockout , Ligante OX40 , Especificidade do Receptor de Antígeno de Linfócitos T , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologia , Doadores de Tecidos , Transplante Homólogo , Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/genética , Fatores de Necrose Tumoral/fisiologiaRESUMO
In the absence of TNF, mice infected with Mycobacterium avium suffer a peculiar disintegration of the granulomas, with extensive apoptosis and necrosis of their cells, occurring during the course of the infection and leading to the death of the animals within a few days of its onset. The survival time depends on the virulence of the infecting strain as well as on the dose and route of infection. Intravenously infected mice developed the typical lesions in hepatic granulomas whereas aerosol-infected animals developed them in the lung granulomas. At the onset of the development of pulmonary granuloma disintegration, extensive expansion of T cells, with intense up-regulation of activation markers, massive exacerbation of their ability to secrete IFN-gamma, and increased cytotoxic activity of both CD4(+) and CD8(+) T cells were observed. Forced expression of Bcl2 did not prevent the early death of infected TNF-deficient mice leading merely to a modest increase in survival times. The expression of the FasL on T cells was not affected but there was an intense up-regulation of the TRAIL in T cells and, in particular, myeloid cells. We thus show that an exacerbated immune response occurs in TNF-deficient hosts during M. avium infections that leads to enhanced IFN-gamma production and late up-regulation of TRAIL which may contribute to granuloma disintegration.
Assuntos
Infecções por Mycobacterium/imunologia , Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/imunologia , Animais , Apoptose/imunologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Regulação para Baixo/imunologia , Granuloma/imunologia , Granuloma/microbiologia , Granuloma/patologia , Injeções Intravenosas , Pulmão/imunologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infecções por Mycobacterium/microbiologia , Infecções por Mycobacterium/mortalidade , Mycobacterium avium/imunologia , Mycobacterium avium/isolamento & purificação , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2 , Taxa de Sobrevida , Linfócitos T/imunologia , Ligante Indutor de Apoptose Relacionado a TNF/imunologiaRESUMO
TNF-like weak inducer of apoptosis (TWEAK), a member of the TNF superfamily, is a prominent inducer of proinflammatory cytokines in vitro and in vivo. We previously found that kidney cells display the TWEAK receptor Fn14, and that TWEAK stimulation of mesangial cells and podocytes induces a potent proinflammatory response. Several of the cytokines up-regulated in the kidney in response to TWEAK are instrumental in Lupus nephritis; we therefore hypothesized that TWEAK/Fn14 interactions may be important in the cascade(s) leading to renal damage in systemic Lupus erythematosus. In this study, we analyzed the effects of Fn14 deficiency in the chronic graft-vs-host model of SLE, and the benefits of treatment with an anti-TWEAK mAb in this mouse model. We found that anti-nuclear Ab titers were no different between C57BL/6 Fn14 wild-type and deficient mice injected with alloreactive bm12 splenocytes. However, kidney disease was significantly less severe in Fn14 knockout mice. Furthermore, kidney IgG deposition, IL-6, MCP-1, RANTES, and IP-10, as well as macrophage infiltration, were significantly decreased in Fn14-deficient mice with induced lupus. Similarly, mice with induced Lupus treated with an anti-TWEAK neutralizing mAb had significantly diminished kidney expression of IL-6, MCP-1, IL-10, as well as proteinuria, but similar autoantibody titers, as compared with control-treated mice. We conclude that TWEAK is an important mediator of kidney damage that acts by promoting local inflammatory events, but without impacting adaptive immunity in this experimental LN model. Thus, TWEAK blockade may be a novel therapeutic approach to reduce renal damage in SLE.
Assuntos
Doença Enxerto-Hospedeiro/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Nefrite Lúpica/imunologia , Receptores do Fator de Necrose Tumoral/metabolismo , Fatores de Necrose Tumoral/metabolismo , Animais , Anticorpos/administração & dosagem , Anticorpos/farmacologia , Anticorpos/uso terapêutico , Autoanticorpos/imunologia , Quimiocinas/efeitos dos fármacos , Doença Crônica , Citocina TWEAK , Citocinas/efeitos dos fármacos , Citocinas/genética , Modelos Animais de Doenças , Feminino , Doença Enxerto-Hospedeiro/patologia , Imunoglobulina G/imunologia , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/patologia , Nefrite Lúpica/tratamento farmacológico , Nefrite Lúpica/patologia , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteinúria/tratamento farmacológico , Receptores do Fator de Necrose Tumoral/deficiência , Sensibilidade e Especificidade , Receptor de TWEAK , Fatores de Necrose Tumoral/deficiênciaRESUMO
Costimulatory cross-talk can occur at multiple cellular levels to potentiate expansion and polarization of Th responses. Although OX40L ligand (OX40L) is thought to play a key role in Th2 development, the critical cellular source of this molecule has yet to be identified. In this study, we demonstrate that OX40L expression by the initiating dendritic cell (DC) is a fundamental requirement for optimal induction of primary and memory Th2 responses in vivo. Analysis of the kinetics of the residual Th2 response primed by OX40L-deficient DC suggested a failure to stimulate appropriate expansion and/or survival of T cells, rather than an inability to polarize per se. The dependence upon OX40L was predominantly due to the provision of signaling through OX40 rather than retrograde signaling to the DC. Mechanistically, impaired Th2 priming in the absence of OX40L was not due to exaggerated regulation because there was no evidence of increased expansion or function of regulatory cell populations, suppression through IL-10 production, or hyporesponsiveness to secondary challenge. These data define a critical role for DC-derived OX40L in the induction and development of Th2 responses in vivo.
Assuntos
Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Memória Imunológica , Ativação Linfocitária/imunologia , Glicoproteínas de Membrana/biossíntese , Transdução de Sinais/imunologia , Células Th2/imunologia , Células Th2/metabolismo , Fatores de Necrose Tumoral/biossíntese , Transferência Adotiva , Animais , Polaridade Celular/imunologia , Células Cultivadas , Células Dendríticas/transplante , Regulação da Expressão Gênica/imunologia , Injeções Intraperitoneais , Ligantes , Glicoproteínas de Membrana/deficiência , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/fisiologia , Camundongos , Ligante OX40 , Receptores OX40/fisiologia , Fatores de Necrose Tumoral/deficiência , Fatores de Necrose Tumoral/genética , Fatores de Necrose Tumoral/fisiologiaRESUMO
Tumor necrosis factor (TNF) is critical and non-redundant to control Mycobacterium tuberculosis infection and cannot be replaced by other proinflammatory cytokines. Overproduction of TNF may cause immunopathology, while TNF neutralization reactivates latent and chronic, controlled infection, which is relevant for the use of neutralizing TNF therapies in patients with rheumatoid arthritis.