RESUMO
Neospora caninum is a protozoan associated with abortions in ruminants and neuromuscular disease in dogs. Classically, the immune response against apicomplexan parasites is characterized by the production of proinflammatory cytokines, such as IL-12, IFN-γ and TNF. TNF is mainly produced during the acute phases of the infections and binds to TNF receptor 1 (CD120a, p55, TNFR1) activating a variety of cells, hence playing an important role in the induction of the inflammatory process against diverse pathogens. Thus, in this study, we aimed to evaluate the role of TNF in cellular and humoral immune responses during N. caninum infection. For this purpose, we used a mouse model of infection based on wildtype (WT) and genetically deficient C57BL/6 mice in TNFR1 (Tnfr1-/-). We observed that Tnfr1-/- mice presented higher mortality associated with inflammatory lesions and increased parasite burden in the brain after the infection with N. caninum tachyzoites. Moreover, Tnfr1-/- mice showed a reduction in nitric oxide (NO) levels in vivo. We also observed that Tnfr1-/- mice showed enhanced serum concentration of antigen-specific IgG2 subclass, while IgG1 production was significantly reduced compared to WT mice, suggesting that TNFR1 is required for regular IgG subclass production and antigen recognition. Based on our results, we conclude that the TNF-TNFR1 complex is crucial for mediating host resistance during the infection by N. caninum.
Assuntos
Coccidiose , Neospora , Receptores Tipo I de Fatores de Necrose Tumoral , Fator de Necrose Tumoral alfa/imunologia , Animais , Coccidiose/imunologia , Citocinas , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Gravidez , Receptores Tipo I de Fatores de Necrose Tumoral/imunologiaRESUMO
The type 1 TNF-α receptor (TNFR1) has a central role in initiating both pro-inflammatory and pro-apoptotic signaling cascades in neutrophils. Considering that TNFR1 signals Staphylococcus aureus protein A (SpA), the aim of this study was to explore the interaction of this bacterial surface protein with neutrophils and keratinocytes to underscore the signaling pathways that may determine the fate of these innate immune cells in the infected tissue during staphylococcal skin infections. Using human neutrophils cultured in vitro and isogenic staphylococcal strains expressing or not protein A, we demonstrated that SpA is a potent inducer of IL-8 in neutrophils and that the induction of this chemokine is dependent on the SpA-TNFR1 interaction and p38 activation. In addition to IL-8, protein A induced the expression of TNF-α and MIP-1α highlighting the importance of SpA in the amplification of the inflammatory response. Protein A contributed to reduce neutrophil mortality prolonging their lifespan upon the encounter with S. aureus. Signaling initiated by SpA modulated the type of neutrophil cell death in vitro and during skin and soft tissue infections (SSTI) in vivo triggering the apoptotic pathway instead of necrosis. Moreover, SpA induced pro-inflammatory cytokines in keratinocytes, modulating their survival in vitro and preventing the exacerbated necrosis and ulceration of the epithelium during SSTI in vivo. Taken together, these results highlight the importance of the inflammatory signaling induced by protein A in neutrophils and skin epithelial cells. The ability of protein A to modulate the neutrophil/epithelial cell death program in the skin is of clinical relevance considering that lysis of neutrophils and epithelial cells will promote an intense inflammatory response and contribute to tissue damage, a non-desirable feature of complicated SSTI.
Assuntos
Queratinócitos/imunologia , Sistema de Sinalização das MAP Quinases/imunologia , Neutrófilos/imunologia , Proteína Estafilocócica A/imunologia , Staphylococcus aureus/imunologia , Citocinas/imunologia , Humanos , Queratinócitos/microbiologia , Neutrófilos/microbiologia , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/imunologiaRESUMO
BACKGROUND: The association between tumor necrosis factor (TNF)-α, soluble TNF receptor (sTNFR)1 and sTNFR2 with clinical characteristics of multiple sclerosis (MS) remains unclear. OBJECTIVE: To examine whether TNF-α, sTNFR1 and sTNFR2 are associated with MS diagnosis, disability, disability progression and clinical forms of MS. MATERIALS AND SUBJECTS: The study included 147 patients with relapsing-remitting MS (RRMS), 21 with progressive clinical forms (ProgMS) and 70 controls. Expanded Disability Status Scale (EDSS) evaluated disability as mild (EDSS < 3.0) or moderate/high (EDSS ≥ 3.0). Multiple Sclerosis Severity Score (MSSS) evaluated disability progression as no progression (MSSS < 5) and progression (MSSS ≥ 5). Baseline data of subjects and plasma levels of TNF-α, sTNFR1, sTNFR2 were obtained. RESULTS: The MS diagnosis explained 44.6% and 12.3% of TNF-α and sTNFR2 levels, respectively. Moderate/high disability and disability progression were best predicted by sTNFR1 and age (positively) and ProgMS were best predicted by sTNFR1 (positively) and sTNFR2 (negatively), coupled with age and sex. A composite score reflecting the sTNFR1/sTNFR2 ratio showed a positive association with ProgMS after adjusting for age and sex. CONCLUSION: Increased sTNFR1 and age were positively associated with disability and disability progression, whereas increased sTNFR1 (positively) and sTNFR2 (negatively) were associated with ProgMS, suggesting a distinct role of them in the immunopathological mechanisms of MS.
Assuntos
Esclerose Múltipla/imunologia , Receptores Tipo II do Fator de Necrose Tumoral/imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Fator de Necrose Tumoral alfa/imunologia , Adulto , Avaliação da Deficiência , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de DoençaRESUMO
Staphylococcus aureus is an important human pathogen that causes infections that may present high morbidity and mortality. Among its many virulence factors protein A (SpA) and Staphylococcal binding immunoglobulin protein (Sbi) bind the Fc portion of IgG interfering with opsonophagocytosis. We have previously demonstrated that SpA interacts with the TNF-α receptor (TNFR) 1 through each of the five IgG binding domains and induces the production of pro-inflammatory cytokines and chemokines. The IgG binding domains of Sbi are homologous to those of SpA, which allow us to hypothesize that Sbi might also have a role in the inflammatory response induced by S. aureus. We demonstrate that Sbi is a novel factor that participates in the induction of the inflammatory response during staphylococcal infections via TNFR1 and EGFR mediated signaling as well as downstream MAPKs. The expression of Sbi significantly contributed to IL-6 production and modulated CXCL-1 expression as well as neutrophil recruitment to the site of infection, thus demonstrating for the first time its relevance as a pro-inflammatory staphylococcal antigen in an in vivo model.
Assuntos
Proteínas de Bactérias/imunologia , Proteínas de Transporte/imunologia , Inflamação/imunologia , Infecções Estafilocócicas/imunologia , Proteína Estafilocócica A/imunologia , Staphylococcus aureus/imunologia , Animais , Sítios de Ligação de Anticorpos/imunologia , Quimiocina CXCL1/biossíntese , Receptores ErbB/imunologia , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Feminino , Flavonoides/farmacologia , Imidazóis/farmacologia , Imunoglobulina G/imunologia , Inflamação/microbiologia , Interleucina-6/biossíntese , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Infiltração de Neutrófilos/imunologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Quinazolinas/farmacologia , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Transdução de Sinais/imunologia , Tirfostinas/farmacologia , Fatores de Virulência/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/antagonistas & inibidoresRESUMO
Establishing prevention and therapeutic strategies for osteoarthritis (OA) is necessary to minimize functional disability and the impact of the disease on society. The aim of this study was to determine the effects of an exercise therapy protocol on inflammatory markers, perception of pain, and physical performance in individuals with OA of the knee. The protocol consisted of flexibility training and muscle strengthening over 12 weeks with three 80-min sessions per week. Peripheral blood was collected to determine serum levels of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and soluble forms of the TNF-α receptor (sTNFR1 and sTNFR2). A clinical assessment of the musculoskeletal system and Western Ontario and McMaster Universities (WOMAC) questionnaire were applied to evaluate the specific symptoms of knee OA. Pain intensity was evaluated using a visual analog scale (VAS). All measurements were taken before and after the intervention. Twenty-two individuals (mean age 58.8 ± 6.4 years) completed the protocol. A decrease in the perception of pain was evident on VAS (p < 0.001) and pain subscale of the WOMAC (p < 0.001). In addition, there was a reduction in serum levels of IL-6 (p < 0.001). However, changes in the levels of the TNF-α and its soluble receptors were not statistically significant. Physical function subscale score and the WOMAC global score improved significantly (p < 0.001). The training also promoted an increase in the progression load for all muscles groups analyzed (p < 0.001). Our data suggest that the exercise therapy protocol could be a strategy for reducing IL-6 levels, managing pain, and improving function in individuals with OA of the knee. However, more studies are necessary to investigate the issue.
Assuntos
Artralgia/reabilitação , Terapia por Exercício/métodos , Osteoartrite do Joelho/reabilitação , Treinamento Resistido/métodos , Idoso , Artralgia/fisiopatologia , Biomarcadores , Feminino , Humanos , Interleucina-6/imunologia , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/imunologia , Osteoartrite do Joelho/fisiopatologia , Medição da Dor , Estudos Prospectivos , Amplitude de Movimento Articular , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Receptores Tipo II do Fator de Necrose Tumoral/imunologia , Índice de Gravidade de Doença , Inquéritos e Questionários , Resultado do Tratamento , Fator de Necrose Tumoral alfa/imunologiaRESUMO
AIMS: To define if there is an imbalance in plasma levels of proinflammatory, fibrogenic and antifibrogenic cytokines in patients with liver cirrhosis (LC) and impaired glucose tolerance (IGT) or diabetes mellitus (DM). MATERIAL AND METHODS: We randomly selected 54 out of 100 patients with LC who had normal fasting plasma glucose (FPG) levels. Three groups were formed based on an oral glucose tolerance test (OGTT) results: 18 patients were normal, 18 had IGT, and 18 had DM. Plasma levels of cytokines were measured: TNF- α, soluble tumor necrosis factor receptor 1 (sTNF-R1), leptin, TGF-ß1, and hepatocyte growth factor (HGF). Also, fasting plasma insulin (FPI) levels were determined and HOMA2-IR was calculated. Results were compared with those of a control group of 18 patients without liver disease nor DM. Intergroup comparison was performed using non parametric tests. RESULTS: Significantly higher sTNF-R1 and lower TGF-ß1 were found in patients with IGT and DM compared to controls. Leptin, HGF, and TNF-α levels showed no significant differences. According to Child-Pugh classification all cytokines levels were impaired in groups B or C as compared to group A. Positive correlations between sTNF-R1 and HOMA2-IR and between leptin and HOMA2-IR were found. CONCLUSIONS: IGT and DM were associated with abnormalities of sTNF-R1 and TGF-ß1 compared to non cirrhotic controls. Among cirrhotic patients impairment of all cytokines were more marked in advanced liver disease. Finally, sTNF-R1 and leptin correlated with IR. These findings suggest that IGT and DM may be causally implicated with liver inflammation process.
Assuntos
Citocinas/imunologia , Diabetes Mellitus Tipo 2/imunologia , Intolerância à Glucose/imunologia , Insulina/sangue , Cirrose Hepática/imunologia , Adulto , Idoso , Glicemia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Feminino , Intolerância à Glucose/sangue , Intolerância à Glucose/complicações , Teste de Tolerância a Glucose , Fator de Crescimento de Hepatócito/imunologia , Humanos , Resistência à Insulina , Leptina/imunologia , Cirrose Hepática/sangue , Cirrose Hepática/complicações , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Fator de Crescimento Transformador beta1/imunologia , Fator de Necrose Tumoral alfa/imunologia , Adulto JovemRESUMO
In obese males obstructive sleep apnoea (OSA) is associated with inflammation and insulin resistance; however, findings are confounded by adipose tissue, a hormone- and cytokine-secreting organ. Our goal was to examine whether in a relatively nonobese population, OSA is associated with sleepiness and inflammation/insulin resistance, and to assess the effects of a 2-month placebo-controlled continuous positive airway pressure (CPAP) use. 77 subjects, 38 middle-aged males and post-menopausal females with OSA and 39 male and female controls, were studied in the sleep laboratory for 4 nights. Measures of sleepiness (objective and subjective), performance, serial 24-h blood samples for interleukin (IL)-6, tumour necrosis factor receptor (TNFR)-1, leptin and adiponectin, and single samples for high-sensitivity C-reactive protein (hsCRP), fasting glucose and insulin levels were obtained. Apnoeic males were significantly sleepier and had significantly higher hsCRP, IL-6, leptin and insulin resistance than controls. Apnoeic females had significantly higher hsCRP; however, objective sleepiness, IL-6, TNFR-1, insulin resistance (Homeostatic Model Assessment index), leptin and adiponectin were similar to controls. CPAP improved subjective sleepiness, but no changes were observed in any of the biomarkers. In conclusion, OSA is associated with sleepiness, inflammation and insulin resistance, even in nonobese males, and this association is stronger in males than in females. Short-term CPAP does not improve the inflammatory/metabolic aberrations in OSA.
Assuntos
Inflamação , Resistência à Insulina , Apneia Obstrutiva do Sono/imunologia , Adiponectina/metabolismo , Glicemia/metabolismo , Índice de Massa Corporal , Proteína C-Reativa/imunologia , Estudos de Casos e Controles , Pressão Positiva Contínua nas Vias Aéreas , Estudos Cross-Over , Feminino , Humanos , Insulina/metabolismo , Interleucina-6/imunologia , Leptina/metabolismo , Masculino , Pessoa de Meia-Idade , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Fatores Sexuais , Apneia Obstrutiva do Sono/metabolismo , Apneia Obstrutiva do Sono/terapia , Resultado do TratamentoRESUMO
The pineal gland, a circumventricular organ, plays an integrative role in defense responses. The injury-induced suppression of the pineal gland hormone, melatonin, which is triggered by darkness, allows the mounting of innate immune responses. We have previously shown that cultured pineal glands, which express toll-like receptor 4 (TLR4) and tumor necrosis factor receptor 1 (TNFR1), produce TNF when challenged with lipopolysaccharide (LPS). Here our aim was to evaluate which cells present in the pineal gland, astrocytes, microglia or pinealocytes produced TNF, in order to understand the interaction between pineal activity, melatonin production and immune function. Cultured pineal glands or pinealocytes were stimulated with LPS. TNF content was measured using an enzyme-linked immunosorbent assay. TLR4 and TNFR1 expression were analyzed by confocal microscopy. Microglial morphology was analyzed by immunohistochemistry. In the present study, we show that although the main cell types of the pineal gland (pinealocytes, astrocytes and microglia) express TLR4, the production of TNF induced by LPS is mediated by microglia. This effect is due to activation of the nuclear factor kappa B (NF-kB) pathway. In addition, we observed that LPS activates microglia and modulates the expression of TNFR1 in pinealocytes. As TNF has been shown to amplify and prolong inflammatory responses, its production by pineal microglia suggests a glia-pinealocyte network that regulates melatonin output. The current study demonstrates the molecular and cellular basis for understanding how melatonin synthesis is regulated during an innate immune response, thus our results reinforce the role of the pineal gland as sensor of immune status.
Assuntos
Melatonina/biossíntese , Neuroglia/metabolismo , Comunicação Parácrina/fisiologia , Glândula Pineal/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/biossíntese , Fatores de Necrose Tumoral/metabolismo , Animais , Células Cultivadas , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Lipopolissacarídeos/farmacologia , Masculino , Melatonina/imunologia , Neuroglia/citologia , Neuroglia/imunologia , Comunicação Parácrina/efeitos dos fármacos , Glândula Pineal/citologia , Glândula Pineal/imunologia , Ratos , Ratos Wistar , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Fatores de Necrose Tumoral/imunologiaRESUMO
While cytokines are major regulators of macrophage activation following host-pathogen interactions, they also act to limit inflammation to avoid tissue damage. In previous studies we reported the development of progressive Yersinia enterocolitica-induced reactive arthritis (ReA) in mice lacking the tumor necrosis factor receptor p55 (TNFRp55). In this work, we analyzed the response of TNFRp55â»/â» macrophages to Y. enterocolitica antigens. We found higher concentration of nitric oxide (NO) in TNFRp55â»/â» compared to wild-type macrophages in response to heat-killed Yersinia (HKY) and Yersinia outer membranes (OM). Moreover, Toll-like receptor (TLR)4 expression was increased in OM-stimulated TNFRp55â»/â» versus wild-type (WT) macrophages. Accordingly, NO production was inhibited in TLR4-deficient macrophages following stimulation with OM, suggesting that LPS may function as a major OM component implicated in these responses. Thus, augmented NO production together with enhanced expression of inducible nitric oxide synthase (iNOS) and higher IL-6 production, may provide a pro-inflammatory setting in Yersinia LPS-stimulated TNFRp55â»/â» macrophages. Augmented synthesis of NO and IL-6 was prevented by treatment with Polymyxin B, or by exposure to a specific NF-κB p65 oligonucleotide antisense, indicating the involvement of TLR4-mediated NF-κB activation in the unleashed pro-inflammatory response triggered by TNFRp55 deficiency. Thus, TNFRp55 modulates macrophage functions in response to Yersinia LPS stimulation through mechanisms involving NO, IL-6 and NF-κB pathways, suggesting an essential regulatory role of TNF via TNFRp55 signaling.
Assuntos
Interleucina-6/metabolismo , Macrófagos Peritoneais/metabolismo , Óxido Nítrico/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/metabolismo , Receptores Chamariz do Fator de Necrose Tumoral/metabolismo , Yersinia enterocolitica/imunologia , Animais , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/metabolismo , Células Cultivadas , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/imunologia , Inflamação , Interleucina-6/genética , Interleucina-6/imunologia , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/metabolismo , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/patologia , Camundongos , Camundongos Knockout , NF-kappa B/genética , NF-kappa B/metabolismo , Oligodesoxirribonucleotídeos Antissenso/genética , Polimixina B/farmacologia , Proibitinas , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Receptores Chamariz do Fator de Necrose Tumoral/genética , Receptores Chamariz do Fator de Necrose Tumoral/imunologiaRESUMO
Reactive arthritis (ReA) is a type of arthritis originating from certain gastrointestinal or genitourinary infections. In previous studies, we reported the development of progressive Yersinia enterocolitica-induced ReA in mice lacking TNFR p55; however, the mechanisms underlying this effect are still uncertain. In this study, we investigated the impact of TNFR p55 deficiency in modulating Ag-specific Th1 and Th17 responses during this arthritogenic process. We found more severe ReA in TNFRp55(-/-) mice compared with their wild-type (WT) counterparts. This effect was accompanied by increased levels of Yersinia LPS in the joints of knockout mice. Analysis of the local cytokine profile revealed greater amounts of IFN-γ and IL-17 in arthritic joints of TNFRp55(-/-) mice compared with WT mice at day 21 postinfection. Moreover, altered IL-17 and IFN-γ production was observed in mesenteric and inguinal lymph nodes of Yersinia-infected TNFRp55(-/-) mice, as well as in spleen cells obtained from infected mice and restimulated ex vivo with bacterial Ags. Increased levels of cytokine secretion were associated with a greater frequency of CD4(+)IL-17(+), CD4(+)IFN-γ(+), and IL-17(+)IFN-γ(+) cells in TNFRp55(-/-) mice compared with WT mice. Remarkably, Ab-mediated blockade of IL-17 and/or IFN-γ resulted in reduced joint histological scores in TNFRp55(-/-) mice. A mechanistic analysis revealed the involvement of p40, a common subunit of heterodimeric IL-12 and IL-23, in the generation of augmented IFN-γ and IL-17 production under TNFR p55 deficiency. Taken together, these data indicate that, in the absence of TNFR p55 signaling, Th1 and Th17 effector cells may act in concert to sustain the inflammatory response in bacterial-induced arthritogenic processes.
Assuntos
Artrite Reativa/imunologia , Interferon gama/imunologia , Interleucina-17/imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Subpopulações de Linfócitos T/imunologia , Animais , Artrite Reativa/metabolismo , Separação Celular , Citocinas/biossíntese , Citocinas/imunologia , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Interferon gama/biossíntese , Interleucina-17/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores Tipo I de Fatores de Necrose Tumoral/deficiência , Transdução de Sinais/imunologia , Células Th1/imunologia , Yersiniose/complicações , Yersiniose/imunologiaRESUMO
Interleukin-6 (IL-6) is an inflammatory cytokine known to modulate muscle pain. However, the mechanisms underlying this effect still remain unclear. Here we show that the injection of IL-6 into mice gastrocnemius muscle evoked a time- and dose-dependent mechanical hyperalgesia. This effect is in part dependent on the presence of gp130 expression in inflammatory cells in the gastrocnemius muscle as well as in DRG neurons. We also demonstrated an increased inflammatory cell recruitment and cytokines levels, namely TNF-α, IL-1ß and KC. TNFR1(-/-) mice or mice pre-treated with the selective CXCR2 antagonist, SB225002, with the anti-macrophage, anti-TNF-α or anti-KC antibodies or with IL-1 receptor antagonist (IL-1RA) showed decreased IL-6-mediated mechanical hyperalgesia. Furthermore, systemic pre-treatment with the classically used drugs indomethacin, celecoxib, guanetidine, morphine, thalidomide or dexamethasone, also prevented IL-6-induced muscle pain. Likewise, local pre-treatment with inhibitors of phospholipase A2 (PACOCF3), phospholipase C (U73122), protein kinase C (GF109203X), protein kinase A (KT-5720) or with phosphatidylinositol 3-kinase (AS605204) also consistently diminished IL-6-induced muscle hyperalgesia. The intramuscular injection of the selective inhibitors of p38 MAPK (SB203580), ERK (PD98059) or JNK (SP60015) also prevented IL-6-mediated muscular pain. Simultaneous flow cytometry measurements revealed that ERK, p38 MAPK and JNK were phosphorylated as early as 5 min after IL-6 injection. These findings provided new evidence indicating that IL-6 exerts a relevant role in the development and maintenance of muscular hyperalgesia. The IL-6-mediated muscular pain response involves resident cell activation, polymorphonuclear cell infiltration, cytokine production, prostanoids and sympathomimetic amines release and the activation of intracellular pathways, especially MAPKs.
Assuntos
Hiperalgesia/induzido quimicamente , Hiperalgesia/patologia , Hiperalgesia/prevenção & controle , Interleucina-6/efeitos adversos , Músculo Esquelético/metabolismo , Análise de Variância , Animais , Anticorpos/administração & dosagem , Receptor gp130 de Citocina/metabolismo , Citocinas/metabolismo , Relação Dose-Resposta a Droga , Interações Medicamentosas , Inibidores Enzimáticos/administração & dosagem , Gânglios Espinais/metabolismo , Hexosaminidases/metabolismo , Inflamação/induzido quimicamente , Injeções Intramusculares/métodos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Peroxidase/metabolismo , Compostos de Fenilureia/administração & dosagem , Fosforilação/efeitos dos fármacos , Receptores Tipo I de Fatores de Necrose Tumoral/deficiência , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Fatores de TempoRESUMO
Trypanosoma cruzi (T. cruzi) infected C57BL/6 mice developed a progressive fatal disease due to an imbalance in the profile of circulating related compounds accompanying infection like tumor necrosis factor alpha (TNFalpha). TNFalpha has been proposed as an important effector molecule in apoptosis. In this work, we evaluate inflammation and the proteins involved in apoptotic process in liver of infected mice and the role of TNFalpha. C57BL6/mice were infected subcutaneously with 100 viable trypomastigotes of Tulahuén strain of T cruzi. One set of these animals were treated with 375 microg of antihuman TNFalpha blocking antibody. Animals were sacrificed at 14 days post-infection (p.i).The analyses of Bcl-2 family proteins revealed an increase of the pro-apoptotic proteins Bax and tBid in T. cruzi-infected mice. Compared with control animals, cytochrome c release was increased. Apoptosis was also induced in infected mice. Anti-TNFalpha treatment decreases hepatic apoptosis. Our results suggest that T. cruzi infection induces programmed cell death in the host liver by increase of TNFalpha production, associated with TNF-R1 over-expression, that set in motion the Bid cleavage and mitochondrial translocation, Bax mitochondrial translocation, cytochrome c release, and ultimately apoptosis induction.
Assuntos
Morte Celular/imunologia , Doença de Chagas/imunologia , Inflamação , Fígado/imunologia , Fígado/parasitologia , Trypanosoma cruzi/imunologia , Fator de Necrose Tumoral alfa/imunologia , Animais , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/imunologia , Citocromos c/metabolismo , Humanos , Marcação In Situ das Extremidades Cortadas , Inflamação/imunologia , Inflamação/microbiologia , Fígado/citologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Trypanosoma cruzi/patogenicidade , Fator de Necrose Tumoral alfa/genética , Proteína X Associada a bcl-2/imunologia , Proteína bcl-X/imunologiaRESUMO
In Chagas disease, understanding how the immune response controls parasite growth but also leads to heart damage may provide insight into the design of new therapeutic strategies. Tumor necrosis factor-alpha (TNF-alpha) is important for resistance to acute Trypanosoma cruzi infection; however, in patients suffering from chronic T. cruzi infection, plasma TNF-alpha levels correlate with cardiomyopathy. Recent data suggest that CD8-enriched chagasic myocarditis formation involves CCR1/CCR5-mediated cell migration. Herein, the contribution of TNF-alpha, especially signaling through the receptor TNFR1/p55, to the pathophysiology of T. cruzi infection was evaluated with a focus on the development of myocarditis and heart dysfunction. Colombian strain-infected C57BL/6 mice had increased frequencies of TNFR1/p55+ and TNF-alpha+ splenocytes. Although TNFR1-/- mice exhibited reduced myocarditis in the absence of parasite burden, they succumbed to acute infection. Similar to C57BL/6 mice, Benznidazole-treated TNFR1-/- mice survived acute infection. In TNFR1-/- mice, reduced CD8-enriched myocarditis was associated with defective activation of CD44+CD62Llow/- and CCR5+ CD8+ lymphocytes. Also, anti-TNF-alpha treatment reduced the frequency of CD8+CCR5+ circulating cells and myocarditis, though parasite load was unaltered in infected C3H/HeJ mice. TNFR1-/- and anti-TNF-alpha-treated infected mice showed regular expression of connexin-43 and reduced fibronectin deposition, respectively. Furthermore, anti-TNF-alpha treatment resulted in lower levels of CK-MB, a cardiomyocyte lesion marker. Our results suggest that TNF/TNFR1 signaling promotes CD8-enriched myocarditis formation and heart tissue damage, implicating the TNF/TNFR1 signaling pathway as a potential therapeutic target for control of T. cruzi-elicited cardiomyopathy.
Assuntos
Anti-Inflamatórios/farmacologia , Anticorpos Monoclonais/farmacologia , Linfócitos T CD8-Positivos/imunologia , Cardiomiopatia Chagásica/imunologia , Receptores CCR5/imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/antagonistas & inibidores , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Animais , Movimento Celular , Cardiomiopatia Chagásica/tratamento farmacológico , Doença Crônica , Feminino , Citometria de Fluxo , Imuno-Histoquímica , Infliximab , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptores Tipo I de Fatores de Necrose Tumoral/sangue , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Transdução de Sinais , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/imunologiaRESUMO
In Chagas disease, understanding how the immune response controls parasite growth but also leads to heart damage may provide insight into the design of new therapeutic strategies. Tumor necrosis factor-alpha (TNF-á) is important for resistance to acute Trypanosoma cruzi infection; however, in patients suffering from chronic T. cruzi infection, plasma TNF-á levels correlate with cardiomyopathy. Recent data suggest that CD8-enriched chagasic myocarditis formation involves CCR1/CCR5-mediated cell migration. Herein, the contribution of TNF-á, especially signaling through the receptor TNFR1/p55, to the pathophysiology of T. cruzi infection was evaluated with a focus on the development of myocarditis and heart dysfunction. Colombian strain-infected C57BL/6 mice had increased frequencies of TNFR1/p55+ and TNF-á+ splenocytes. Although TNFR1-/- mice exhibited reduced myocarditis in the absence of parasite burden, they succumbed to acute infection. Similar to C57BL/6 mice, Benznidazole-treated TNFR1-/- mice survived acute infection. In TNFR1-/- mice, reduced CD8-enriched myocarditis was associated with defective activation of CD44+CD62Llow/- and CCR5+ CD8+ lymphocytes. Also, anti-TNF-á treatment reduced the frequency of CD8+CCR5+ circulating cells and myocarditis, though parasite load was unaltered in infected C3H/HeJ mice. TNFR1-/- and anti-TNF-á-treated infected mice showed regular expression of connexin-43 and reduced fibronectin deposition, respectively. Furthermore, anti-TNF-á treatment resulted in lower levels of CK-MB, a cardiomyocyte lesion marker. Our results suggest that TNF/TNFR1 signaling promotes CD8-enriched myocarditis formation and heart tissue damage, implicating the TNF/TNFR1 signaling pathway as a potential therapeutic target for control of T. cruzi-elicited cardiomyopathy.
Assuntos
Animais , Feminino , Camundongos , Anti-Inflamatórios/farmacologia , Anticorpos Monoclonais/farmacologia , /imunologia , Cardiomiopatia Chagásica/imunologia , /imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/antagonistas & inibidores , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Movimento Celular , Doença Crônica , Cardiomiopatia Chagásica/tratamento farmacológico , Citometria de Fluxo , Imuno-Histoquímica , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptores Tipo I de Fatores de Necrose Tumoral/sangue , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Transdução de Sinais , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/imunologiaRESUMO
Tumor necrosis factor alpha (TNF alpha) enhances proliferation of chemically-induced mammary tumors and of T47D human cell line through not fully understood pathways. Here, we explored the intracellular signaling pathways triggered by TNF alpha, the participation of TNF alpha receptor (TNFR) 1 and TNFR2 and the molecular mechanism leading to breast cancer growth. We demonstrate that TNFalpha induced proliferation of C4HD murine mammary tumor cells and of T47D cells through the activation of p42/p44 MAPK, JNK, PI3-K/Akt pathways and nuclear factor-kappa B (NF-kappa B) transcriptional activation. A TNF alpha-specific mutein selectively binding to TNFR1 induced p42/p44 MAPK, JNK, Akt activation, NF-kappa B transcriptional activation and cell proliferation, just like wild-type TNF alpha, while a mutein selective for TNFR2 induced only p42/p44 MAPK activation. Interestingly, blockage of TNFR1 or TNFR2 with specific antibodies was enough to impair TNF alpha signaling and biological effect. Moreover, in vivo TNF alpha administration supported C4HD tumor growth. We also demonstrated, for the first time, that injection of a selective inhibitor of NF-kappa B activity, Bay 11-7082, resulted in regression of TNF alpha-promoted tumor. Bay 11-7082 blocked TNF alpha capacity to induce cell proliferation and up-regulation of cyclin D1 and of Bcl-xLin vivo and in vitro. Our results reveal evidence for TNF alpha as a breast tumor promoter, and provide novel data for a future therapeutic approach using TNF alpha antagonists and NF-kappa B pharmacological inhibitors in established breast cancer treatment.
Assuntos
Carcinoma Ductal de Mama/fisiopatologia , Proliferação de Células/efeitos dos fármacos , Neoplasias Mamárias Experimentais/fisiopatologia , Neoplasias Hormônio-Dependentes/fisiopatologia , Receptores Tipo I de Fatores de Necrose Tumoral/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia , Animais , Proteínas Reguladoras de Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Carcinógenos , Carcinoma Ductal de Mama/induzido quimicamente , Carcinoma Ductal de Mama/tratamento farmacológico , Linhagem Celular Tumoral , Feminino , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/efeitos dos fármacos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Neoplasias Mamárias Experimentais/induzido quimicamente , Neoplasias Mamárias Experimentais/tratamento farmacológico , Acetato de Medroxiprogesterona , Camundongos , Camundongos Endogâmicos BALB C , Proteína Quinase 1 Ativada por Mitógeno/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/efeitos dos fármacos , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , NF-kappa B/antagonistas & inibidores , NF-kappa B/metabolismo , Neoplasias Hormônio-Dependentes/induzido quimicamente , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Nitrilas/farmacologia , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Transdução de Sinais/imunologia , Sulfonas/farmacologia , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/imunologiaRESUMO
There is pre-clinical evidence that therapies targeting IL-18 might be beneficial in controlling arthropathies, which are accompanied by hypernociception (nociceptor sensitization). In the present study, we addressed the hypernociceptive role of IL-18 in a model of antigen-induced inflammation in mice and its mechanisms. In naïve mice, the intraplantar injection of IL-18 induced dose- and time-dependent mechanical hypernociception, which was inhibited in IFN-gamma deficient (-/-) mice, and by the pre-treatment with bosentan (dual endothelin [ET] receptor antagonist), BQ123 (ET(A) receptor antagonist) or indomethacin (cyclooxygenase inhibitor). IL-18 hypernociception was unaffected in TNFR1(-/-) mice or by the pre-treatment with sIL-15Ralpha (soluble form of IL-15 receptor), BQ788 (ET(B) receptor antagonist) or guanethidine (sympathetic blocker). The ovalbumin (OVA) challenge-induced mechanical hypernociception in immunized mice was inhibited by the pre-treatment with anti-IL-18 antibody or in IL-18(-/-) mice. Furthermore, IL-18 induced significant IFN-gamma production in the paw skin of naïve mice. The OVA challenge-induced IFN-gamma and ET-1 productions were inhibited in IL-18(-/-) immunized mice, as well as ET-1 production in IFN-gamma(-/-) immunized mice. In addition, significant PGE2 production was detected after IL-18 or ET-1 (via ET(A) receptors) injection in naïve mice. Taken together with previous data, these results suggest that IL-18 plays a significant role in antigen-induced inflammatory hypernociception via the production of IFN-gamma, ET-1 and PGE2. Thus, IL-18 and IL-18-downstream mediators demonstrated herein might constitute targets to inhibit antigen-induced inflammatory pain.
Assuntos
Interferon gama/imunologia , Interleucina-18/imunologia , Limiar da Dor/fisiologia , Dor/imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Transdução de Sinais/imunologia , Animais , Antígenos/imunologia , Dinoprostona/metabolismo , Relação Dose-Resposta a Droga , Interferon gama/genética , Interleucina-18/administração & dosagem , Interleucina-18/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ovalbumina/imunologia , Prostaglandina-Endoperóxido Sintases/imunologia , Prostaglandina-Endoperóxido Sintases/metabolismo , Receptor de Endotelina A/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Estresse Mecânico , Fatores de TempoRESUMO
OBJECTIVES: The pathogenesis of reactive arthritis (ReA), an aseptic synovitis that follows an extra-articular infection, is incompletely known. We studied the impact of tumour necrosis factor receptor (TNFR) p55 deficiency on the progression to ReA after oral Yersinia enterocolitica O:3 infection, the Yersinia antigens triggering articular inflammation and a possible articular TNFRp55-mediated mechanism that protects against ReA. METHODS: Wild-type C57BL/6 and TNFRp55-/- mice were orogastrically infected with Y. enterocolitica O:3 and monitored for survival and arthritis development. The bacterial load was determined in mesenteric lymph nodes (MLNs), the spleen and joints. Interferon (IFN)-gamma, TNF-alpha and IL-10 mRNA expression in MLN and joints were analysed by reverse transcription-polymerase chain reaction (RT-PCR). Articular antibodies to Yersinia antigens, TNF-alpha protein and nitric oxide (NO) levels were assessed. Acute arthritis was evaluated after joint injection of Yersinia antigens. RESULTS: The survival rate was 60% in TNFRp55-/- mice. They showed impaired bacterial clearance in MLN, the spleen and joints, and excessive mRNA expression of pro-inflammatory cytokines in MLN. Clinical and histological examinations revealed that TNFRp55-/- mice developed severe arthritis. Moreover, augmented articular outer membrane protein (OMP)-specific antibodies and TNF-alpha but impaired NO levels were detected in TNFRp55-/- mice. Synovial inflammatory response was detected by joint OMP injection. CONCLUSIONS: TNFRp55-mediated immune mechanisms prevent ReA development after oral infection with Y. enterocolitica O:3. Yersinia OMPs are the relevant antigens triggering ReA. NO induction through TNFRp55 signalling could have a local antibacterial function to prevent ReA. This study could contribute to ReA-specific therapeutic studies.
Assuntos
Antígenos de Bactérias/imunologia , Artrite Experimental/imunologia , Artrite Reativa/imunologia , Receptores Tipo I de Fatores de Necrose Tumoral/imunologia , Yersiniose/imunologia , Yersinia enterocolitica/imunologia , Animais , Anticorpos Antibacterianos/biossíntese , Artrite Experimental/microbiologia , Artrite Experimental/patologia , Artrite Reativa/microbiologia , Artrite Reativa/patologia , Suscetibilidade a Doenças , Articulações/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico/biossíntese , Receptores Tipo I de Fatores de Necrose Tumoral/deficiência , Fator de Necrose Tumoral alfa/biossíntese , Yersiniose/patologiaRESUMO
Inflammatory immune reactions in response to periodontopathogens are thought to protect the host against infection, but may trigger periodontal destruction. Thus, we examined the mechanisms by which the proinflammatory cytokine tumour necrosis factor (TNF)-alpha modulates the outcome of Actinobacillus actinomycetemcomitans-induced periodontal disease in mice. Our results showed that TNF-alpha receptor p55-deficient mice [p55TNF-knock-out (KO)] developed a less severe periodontitis in response to A. actinomycetemcomitans infection, characterized by significantly less alveolar bone loss and inflammatory reaction. Real-time polymerase chain reaction (PCR) demonstrated that levels of chemokines (CXCL1, 3 and 10; CCL3 and 5) and their receptors (CXCR2 and 3, CCR5) were lower in p55TNF-KO mice, as were matrix metalloproteinase (MMP)-1, 2 and 9 and receptor activator of nuclear factor kB ligand (RANKL) mRNA levels. However, the absence of the TNF-alpha p55 results in an impairment of protective immunity to A. actinomycetemcomitans infection, characterized by increased bacterial load and higher levels of C-reactive protein during the course of disease. Such impaired host response may be the result of the reduced chemoattraction of lymphocytes, neutrophils and macrophages, and reduced inducible nitric oxide synthase expression (iNOS) and myeloperoxidase (MPO) production in periodontal tissues of p55 TNF-KO mice. Our results demonstrate the mechanisms involved determining periodontal disease severity by TNF-alpha receptor p55, and its role in providing immune protection to A. actinomycetemcomitans periodontal infection.