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1.
Artigo em Inglês | MEDLINE | ID: mdl-31342533

RESUMO

BACKGROUND: Lifestyle modifications remain the cornerstone of treatment in non-alcoholic fatty liver disease (NAFLD). However, they requently fail related to the inability of patients to implement lasting changes. AIMS: To evaluate the effects of a short, web-based, individualised exercise program on non-invasive markers of hepatic steatosis, inflammation and fibrosis. METHODS: Patients with histologically confirmed NAFLD underwent an 8-week, web-based, individualised exercise program that contained bidirectional feedback. RESULTS: Forty-four patients entered the study and 41 completed the assigned training goal (93.2%). In the completer population, 8 weeks of individualised exercise increased the VO2peak by 12.2% compared to baseline (P < .001). ALT and AST decreased by 14.3% (P = .002) and 18.2% (P < .001) and remained at this level until follow-up 12 weeks after the intervention. Markers of inflammation including hsCRP, ferritin, and M30 decreased. In parallel, gut microbiota exhibited increased metagenomic richness (P < .05) and at the taxonomic levels Bacteroidetes and Euryarchaeota increased whereas Actinobacteria phylum decreased. Surrogate scores of steatosis and fibrosis including the fatty liver index (FLI), FiB-4, APRI and transient elastography showed significant reductions. In parallel, a marker of procollagen-3 turnover (PRO-C3) decreased while C4M2, reflecting type IV collagen, degradation increased suggesting beneficial hepatic fibrosis remodelling from exercise. Also, an enhancement in health-related quality of life was reported. CONCLUSION: The current study underlines the plausibility and potential of an 8 week individualised web-based exercise program in NAFLD. Clinical trial number: NCT02526732.

2.
Sci Rep ; 9(1): 4007, 2019 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-30850619

RESUMO

Reproducible animal models to recapitulate the pathophysiology of non-alcoholic fatty liver disease (NAFLD) are urgently required to improve the understanding of the mechanisms of liver injury and to explore novel therapeutic options. Current guidelines recommend life-style interventions as first-line therapy for NAFLD and these types of intervention are considered standard-of-care. The current study establishes a reproducible mouse model of a life-style intervention in NAFLD using voluntary wheel running (VWR). Male C57BL/6J mice were fed a high-fat, high-carbohydrate diet (HFD) to induce NAFLD or a corresponding control diet for 12 weeks. Starting at week 9 of the obesogenic NAFLD diet, mice were randomized to either free access to a running wheel or being single caged resembling a sedentary (SED) life-style. VWR induced a transient weight reduction in HFD-fed mice up until week 10. In contrast to the SED mice, VWR mice exhibited normal ALT at the end of the intervention, while the metabolic alterations including elevated fasting glucose, insulin, triglyceride, and total cholesterol levels remained almost unchanged. Additionally, VWR prevented HFD-induced hepatic steatosis by alterations in key liver metabolic processes including the induction of fatty acid ß-oxidation and lipogenesis inhibition following increased AMP-activated protein kinase (AMPK)-α activity. Phosphorylation of the serine kinase Akt in hepatic tissue was enhanced following VWR. Furthermore, VWR mice were protected from HFD-induced expression of pro-inflammatory cytokines, chemokines and liver macrophage infiltration. The SED/HFD group exhibited increasing activity of hepatic nuclear factor (NF)-κB p65, which was absent following exercise in the VWR/HFD group. In summary, in an obesogenic mouse model of NAFLD physical exercise improves fatty acid and glucose homeostasis and protects from macrophage-associated hepatic inflammation.

3.
Tumour Biol ; 40(3): 1010428318764007, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29534639

RESUMO

BACKGROUND: Gastric cancer is common malignancy and exhibits a poor prognosis. At the time of diagnosis, the majority of patients present with metastatic disease which precludes curative treatment. Non-invasive biomarkers which discriminate early from advanced stages or predict the response to treatment are urgently required. This study explored the cytokeratin-18 fragment M30 and full-length cytokeratin-18 M65 in predicting treatment response and survival in a randomized, placebo-controlled trial of advanced gastric cancer. METHODS: Patients enrolled in the SUN-CASE study received sunitinib or placebo as an adjunct to standard therapy with leucovorin (Ca-folinate), 5-fluorouracil, and irinotecan in second or third line. Treatment response rates, progression-free survival and overall survival were assessed during a follow-up period of 12 months. Cytokeratin-18 fragments were analyzed in 52 patients at baseline and day 14 of therapy. RESULTS: Levels of M30 correlated with the presence of metastasis and lymph node involvement and decreased significantly during chemotherapy. Importantly, baseline levels of M30 were significantly higher in patients who failed therapy. In addition, patients who did not respond to treatment were also identifiable at day 14 based on elevated M30 levels. By stepwise regression analysis, M30 at day 14 was identified as independent predictor of treatment response. Likewise, serum levels of full-length cytokeratin-18 M65 at baseline also correlated with treatment failure and progression-free survival. The addition of sunitinib did not exert any effects on serum levels of M30 or M65. CONCLUSION: The cytokeratin-18 fragment M30 at day 14 identifies patients that fail to second- or third-line therapy for advanced gastric cancer. Validation of this non-invasive biomarker in gastric cancer is warranted.


Assuntos
Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Camptotecina/análogos & derivados , Indóis/uso terapêutico , Queratina-18/sangue , Fragmentos de Peptídeos/sangue , Pirróis/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/sangue , Camptotecina/uso terapêutico , Intervalo Livre de Doença , Feminino , Fluoruracila/uso terapêutico , Humanos , Leucovorina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Placebos/uso terapêutico , Neoplasias Gástricas/patologia , Sunitinibe
4.
J Hepatol ; 68(5): 986-995, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29366909

RESUMO

BACKGROUND & AIMS: Interleukin (IL)-1-type cytokines including IL-1α, IL-1ß and interleukin-1 receptor antagonist (IL-1Ra) are among the most potent molecules of the innate immune system and exert biological activities through the ubiquitously expressed interleukin-1 receptor type 1 (IL-1R1). The role of IL-1R1 in hepatocytes during acute liver failure (ALF) remains undetermined. METHODS: The role of IL-1R1 during ALF was investigated using a novel transgenic mouse model exhibiting deletion of all signaling-capable IL-1R isoforms in hepatocytes (Il1r1Hep-/-). RESULTS: ALF induced by D-galactosamine (D-GalN) and lipopolysaccharide (LPS) was significantly attenuated in Il1r1Hep-/- mice leading to reduced mortality. Conditional deletion of Il1r1 decreased activation of injurious c-Jun N-terminal kinases (JNK)/c-Jun signaling, activated nuclear factor-kappa B (NF-κB) p65, inhibited extracellular signal-regulated kinase (ERK) and prevented caspase 3-mediated apoptosis. Moreover, Il1r1Hep-/- mice exhibited reduced local and systemic inflammatory cytokine and chemokine levels, especially TNF-α, IL-1α/ß, IL-6, CC-chemokine ligand 2 (CCL2), C-X-C motif ligand 1 (CXCL-1) and CXCL-2, and a reduced neutrophil recruitment into the hepatic tissue in response to injury. NLRP3 inflammasome expression and caspase 1 activation were suppressed in the absence of the hepatocellular IL-1R1. Inhibition of IL-1R1 using IL-1ra (anakinra) attenuated the severity of liver injury, while IL-1α administration exaggerated it. These effects were lost ex vivo and at later time points, supporting a role of IL-1R1 in inflammatory signal amplification during acute liver injury. CONCLUSION: IL-1R1 in hepatocytes plays a pivotal role in an IL-1-driven auto-amplification of cell death and inflammation in the onset of ALF. LAY SUMMARY: Acute liver injury which can cause lethal liver failure is medicated by a class of proteins called cytokines. Among these, interleukin-1 (IL-1) and the corresponding receptor IL-1R1 play a prominent role in the immune system, but their role in the liver is undetermined. In the current study, a novel mouse model with defective IL-1R1 in liver cells was studied. Mice lacking this receptor in liver cells were protected from cell death to a certain extent. This protection occurred only in the presence of other, neighboring cells, arguing for the involvement of proteins derived from these cells. This effect is called paracrine signaling and the current study has for the first time shown that the IL-1R1 receptor on hepatocytes is involved in acute liver failure in this context. The approved drug anakinra - which blocks IL-1R1 - had the same effect, supporting the proposed mechanism of action. The findings of this study suggest new treatment options for patients with acute liver failure by blocking defined signals of the immune system.

5.
Am J Physiol Gastrointest Liver Physiol ; 314(3): G319-G333, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29191940

RESUMO

Cholestatic liver injury results from impaired bile flow or metabolism and promotes hepatic inflammation and fibrogenesis. Toxic bile acids that accumulate in cholestasis induce apoptosis and contribute to early cholestatic liver injury, which is amplified by accompanying inflammation. The aim of the current study was to evaluate the role of the antiapoptotic caspase 8-homolog cellular FLICE-inhibitory (cFLIP) protein during acute cholestatic liver injury. Transgenic mice exhibiting hepatocyte-specific deletion of cFLIP (cFLIP-/-) were used for in vivo and in vitro analysis of cholestatic liver injury using bile duct ligation (BDL) and the addition of bile acids ex vivo. Loss of cFLIP in hepatocytes promoted acute cholestatic liver injury early after BDL, which was characterized by a rapid release of proinflammatory and chemotactic cytokines (TNF, IL-6, IL-1ß, CCL2, CXCL1, and CXCL2), an increased presence of CD68+ macrophages and an influx of neutrophils in the liver, and resulting apoptotic and necrotic hepatocyte cell death. Mechanistically, liver injury in cFLIP-/- mice was aggravated by reactive oxygen species, and sustained activation of the JNK signaling pathway. In parallel, cytoprotective NF-κB p65, A20, and the MAPK p38 were inhibited. Increased injury in cFLIP-/- mice was accompanied by activation of hepatic stellate cells and profibrogenic regulators. The antagonistic caspase 8-homolog cFLIP is a critical regulator of acute, cholestatic liver injury. NEW & NOTEWORTHY The current paper explores the role of a classical modulator of hepatocellular apoptosis in early, cholestatic liver injury. These include activation of NF-κB and MAPK signaling, production of inflammatory cytokines, and recruitment of neutrophils in response to cholestasis. Because these signaling pathways are currently exploited in clinical trials for the treatment of nonalcoholic steatohepatitis and cirrhosis, the current data will help in the development of novel pharmacological options in these indications.

6.
Oncotarget ; 8(34): 56095-56109, 2017 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-28915576

RESUMO

The transcriptional nuclear factor kappa B (NF-κB)-coactivator B cell leukemia-3 (Bcl-3) is a molecular regulator of cell death and proliferation. Bcl-3 has been shown to be widely expressed in different cancer types including hepatocellular carcinoma (HCC). Its influence on hepatocarcinogenesis is still undetermined. To examine the role of Bcl-3 in hepatocarcinogenesis mice with hepatocyte-specific overexpression of Bcl-3 (Bcl-3Hep) were exposed to diethylnitrosamine (DEN) and phenobarbital (PB). Hepatic Bcl-3 overexpression attenuated DEN/PB-induced hepatocarcinogenesis. Bcl-3Hep mice exhibited a lower number and smaller tumor nodules in response to DEN/PB at 40 weeks of age. Reduced HCC formation was accompanied by a lower rate of cell proliferation and a distinct expression pattern of growth and differentiation-related genes. Activation of c-Jun N-terminal kinase (JNK) and especially extracellular-signal regulated kinase (ERK) was reduced in tumor and tumor-surrounding liver tissue of Bcl-3Hep mice, while p38 and NF-κB p65 were phosphorylated to a higher extent compared to the wild type. In parallel, the absolute number of intrahepatic macrophages, CD8+ T cells and activated B cells was reduced in DEN/PB-treated Bcl-3Hep mice mirroring a reduction of tumor-associated inflammation. Interestingly, at the early time point of 7 weeks following tumor initiation, a higher rate of apoptotic cell death was observed in Bcl-3Hep mice. In summary, hepatocyte-restricted Bcl-3 overexpression reduced hepatocarcinogenesis related to prolonged liver injury early after tumor initiation likely due to decreased survival of DEN/PB-damaged, premalignant cells. Therefore, Bcl-3 could become a novel player in the development of therapeutic and diagnostic tools for HCC.

7.
Cell Death Dis ; 8(6): e2893, 2017 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-28640248

RESUMO

Physical activity confers a broad spectrum of health benefits. Beyond the obvious role in metabolically driven diseases, the role of physical activity in acute liver injury is poorly explored. To study the role of physical activity in acute liver injury, a novel model of voluntary distance running in mice was developed and mice were subjected to acute liver injury induced by N-galactosamine (GalN) and lipopolysaccharide (LPS). Analyses included histological stains, immunoblotting, qRT-PCR and FACS analysis. Voluntary distance running increased to an average of 10.3 km/day after a learning curve. Running lead to a decrease in the absolute numbers of intrahepatic CD4+ T and B lymphocytes and macrophages after 7 weeks. In parallel, hepatic mRNA expression of inflammatory cytokines including IL-6 and IL-1beta, TGF-beta and monocyte chemoattractant protein-1 (MCP-1/CCL2) were suppressed, while TNF-α was not affected by exercise. Likewise, expression of the macrophage-specific antigen F4/80 was downregulated 1.6-fold from exercise. Notably, acute liver injury from GaIN/LPS was significantly blunted following 7 weeks of voluntary exercise as determined by liver histology, a 84.6% reduction of alanine aminotransferase (P<0.01) and a 54.6% reduction of aspartate aminotransferase (P<0.05) compared with sedentary mice. Additionally, proinflammatory cytokines, activation of caspase 3 and JNK were significantly lower, while antiapoptotic protein A20 increased. Voluntary distance running alters the intrahepatic immune phenotype producing an environment that is less susceptible to acute liver injury.


Assuntos
Fígado/imunologia , Fígado/lesões , Alarminas/metabolismo , Animais , Peso Corporal , Quimiocinas/metabolismo , Quimiotaxia , Citocinas/metabolismo , Ativação Enzimática , Galactosamina , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Lipopolissacarídeos , Fígado/metabolismo , Fígado/fisiopatologia , Falência Hepática Aguda/patologia , Falência Hepática Aguda/prevenção & controle , Testes de Função Hepática , Masculino , Camundongos Endogâmicos C57BL , Modelos Animais , NF-kappa B/metabolismo , Condicionamento Físico Animal , Receptores de Reconhecimento de Padrão/metabolismo , Fator de Necrose Tumoral alfa
8.
Oncotarget ; 8(70): 115667-115680, 2017 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-29383190

RESUMO

Background: Organic cation transporters (OCT) are responsible for the uptake of a broad spectrum of endogenous and exogenous substrates. Downregulation of OCT is frequently observed in human hepatocellular carcinoma (HCC) and is associated with a poor outcome. The aim of our current study was to elucidate the impact of OCT3 on hepatocarcinogenesis. Methods: Transcriptional and functional loss of OCT was investigated in primary murine hepatocytes, derived from Oct3-knockout (Oct3-/-; FVB.Slc22a3tm1Dpb ) and wildtype (WT) mice. Liver tumors were induced in Oct3-/- and WT mice with Diethylnitrosamine and Phenobarbital over 10 months and characterized macroscopically and microscopically. Key survival pathways were investigated by Western Blot analysis. Results: Loss of Oct3-/- in primary hepatocytes resulted in significantly reduced OCT activity determined by [3H]MPP+ uptake in vivo. Furthermore, tumor size and quantity were markedly enhanced in Oct3-/- mice (p<0.0001). Oct3-/- tumors showed significant higher proliferation (p<0.0001). Ki-67 and Cyclin D expression were significantly increased in primary Oct3-/- hepatocytes after treatment with the OCT inhibitors quinine or verapamil (p<0.05). Functional inhibition of OCT by quinine resulted in an activation of c-Jun N-terminal kinase (Jnk), especially in Oct3-/- hepatocytes. Conclusion: Loss of Oct3 leads to enhanced proliferation and hepatocarcinogenesis in vivo.

9.
J Hepatol ; 65(6): 1188-1197, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27405060

RESUMO

BACKGROUND & AIMS: The pathomechanisms underlying non-alcoholic fatty liver disease (NAFLD) and the involved molecular regulators are incompletely explored. The nuclear factor-kappa B (NF-κB)-cofactor gene B cell leukemia-3 (Bcl-3) plays a critical role in altering the transcriptional capacity of NF-κB - a key inducer of inflammation - but also of genes involved in cellular energy metabolism. METHODS: To define the role of Bcl-3 in non-alcoholic steatohepatitis (NASH), we developed a novel transgenic mouse model with hepatocyte-specific overexpression of Bcl-3 (Bcl-3Hep) and employed a high-fat, high-carbohydrate dietary feeding model. To characterize the transgenic model, deep RNA sequencing was performed. The relevance of the findings was confirmed in human liver samples. RESULTS: Hepatocyte-specific overexpression of Bcl-3 led to pronounced metabolic derangement, characterized by enhanced hepatic steatosis from increased de novo lipogenesis and uptake, as well as decreased hydrolysis and export of fatty acids. Steatosis in Bcl-3Hep mice was accompanied by an augmented inflammatory milieu and liver cell injury. Moreover, Bcl-3 expression decreased insulin sensitivity and resulted in compensatory regulation of insulin-signaling pathways. Based on in vivo and in vitro studies we identified the transcription factors PPARα, PPARγ and PGC-1α as critical regulators of hepatic metabolism and inflammation downstream of Bcl-3. Metformin treatment improved the metabolic and inflammatory phenotype in Bcl-3Hep mice through modulation of PPARα and PGC-1α. Remarkably, these findings were recapitulated in human NASH, which exhibited increased expression and nuclear localization of Bcl-3. CONCLUSIONS: In summary, Bcl-3 emerges as a novel regulator of hepatic steatosis, insulin sensitivity and inflammation in NASH. LAY SUMMARY: Non-alcoholic fatty liver disease (NAFLD) is considered the most prevalent liver disease worldwide. Patients can develop end-stage liver disease resulting in liver cirrhosis or hepatocellular carcinoma, but also develop complications unrelated to liver disease, e.g., cardiovascular disease. Still there is no full understanding of the mechanisms that cause NAFLD. In this study, genetically engineered mice were employed to examine the role of a specific protein in the liver that is involved in inflammation and the metabolism, namely Bcl-3. By this approach, a better understanding of the mechanisms contributing to disease progression was established. This can help to develop novel therapeutic and diagnostic options for patients with NAFLD.


Assuntos
Proteínas Proto-Oncogênicas/metabolismo , Fatores de Transcrição/metabolismo , Animais , Carcinoma Hepatocelular , Humanos , Inflamação , Insulina , Neoplasias Hepáticas , Camundongos
10.
Immunity ; 39(3): 482-95, 2013 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-23993650

RESUMO

Immune sensing of DNA is critical for antiviral immunity but can also trigger autoimmune diseases such as lupus erythematosus (LE). Here we have provided evidence for the involvement of a damage-associated DNA modification in the detection of cytosolic DNA. The oxidized base 8-hydroxyguanosine (8-OHG), a marker of oxidative damage in DNA, potentiated cytosolic immune recognition by decreasing its susceptibility to 3' repair exonuclease 1 (TREX1)-mediated degradation. Oxidizative modifications arose physiologically in pathogen DNA during lysosomal reactive oxygen species (ROS) exposure, as well as in neutrophil extracellular trap (NET) DNA during the oxidative burst. 8-OHG was also abundant in UV-exposed skin lesions of LE patients and colocalized with type I interferon (IFN). Injection of oxidized DNA in the skin of lupus-prone mice induced lesions that closely matched respective lesions in patients. Thus, oxidized DNA represents a prototypic damage-associated molecular pattern (DAMP) with important implications for infection, sterile inflammation, and autoimmunity.


Assuntos
Dano ao DNA , DNA/metabolismo , Exodesoxirribonucleases/metabolismo , Proteínas de Membrana/metabolismo , Fosfoproteínas/metabolismo , Animais , Células Cultivadas , Reparo do DNA , Guanosina/análogos & derivados , Guanosina/metabolismo , Humanos , Interferon Tipo I , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/imunologia , Lúpus Eritematoso Sistêmico/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neutrófilos/metabolismo , Oxirredução , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo
11.
Eur J Immunol ; 41(10): 3028-39, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21728171

RESUMO

Owing to high rates of tumor relapse, ovarian cancer remains a fatal disease for which new therapeutic approaches are urgently needed. Accumulating evidence indicates that immune stimulation may delay or even prevent disease recurrence in ovarian cancer. In order to elicit proinflammatory signals that induce or amplify antitumor immune reactivity, we mimicked viral infection in ascites-derived ovarian cancer cells. By transfection or electroporation we targeted the synthetic double-stranded RNA poly(I:C) intracellularly in order to activate melanoma differentiation-associated gene-5 (MDA-5), a sensor of viral RNA in the cytosol of somatic cells. Cancer cells reacted with enhanced expression of HLA-class I, release of CXCL10, IL-6, and type I IFN as well as tumor cell apoptosis. Monocytes and monocyte-derived DCs (MoDCs) engulfed MDA-5-activated cancer cells, and subsequently upregulated HLA-class I/II and costimulatory molecules, and secreted CXCL10 and IFN-α. Further, this proinflammatory milieu promoted cytolytic activity and IFN-γ secretion of NK cells. Thus, our data suggest that the engagement of MDA-5 in a whole tumor cell vaccine is a promising approach for the immunotherapy of ovarian cancer.


Assuntos
Apoptose , Células Matadoras Naturais/imunologia , Células Mieloides , Neoplasias Ovarianas/imunologia , Poli I-C/farmacologia , Animais , Ascite , Quimiocina CXCL10/biossíntese , RNA Helicases DEAD-box/metabolismo , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Eletroporação , Feminino , Antígenos de Histocompatibilidade Classe I/biossíntese , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Interferon Tipo I/biossíntese , Helicase IFIH1 Induzida por Interferon , Interferon-alfa/biossíntese , Interleucina-6/biossíntese , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/metabolismo , Ativação Linfocitária , Subpopulações de Linfócitos/imunologia , Linfócitos do Interstício Tumoral/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/imunologia , Monócitos/metabolismo , Células Mieloides/efeitos dos fármacos , Células Mieloides/imunologia , Células Mieloides/metabolismo , Neoplasias Ovarianas/patologia , Poli I-C/administração & dosagem , Transfecção
12.
Cancer Res ; 70(13): 5293-304, 2010 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-20551064

RESUMO

Most malignant cells are poorly immunogenic and fail to elicit an effective antitumor immune response. In contrast, viral infections of cells are promptly detected and eliminated by the immune system. Viral recognition critically hinges on cytosolic nucleic acid receptors that include the proinflammatory RNA helicase retinoic acid-inducible gene-I (RIG-I). Here, we show that targeted delivery of RIG-I agonists induced ovarian cancer cells to upregulate HLA class I and to secrete the proinflammatory cytokines CXCL10, CCL5, interleukin-6, tumor necrosis factor-alpha, and IFN-beta. Ovarian cancer cells stimulated via RIG-I became apoptotic and were readily phagocytosed by monocytes and monocyte-derived dendritic cells, which in turn upregulated HLA class I/II and costimulatory molecules and released CXCL10 and IFN-alpha. Our findings offer proof of principle that mimicking viral infection in ovarian cancer cells triggers an immunogenic form of tumor cell apoptosis that may enhance immunotherapy of ovarian cancer.


Assuntos
RNA Helicases DEAD-box/metabolismo , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/terapia , Apoptose/efeitos dos fármacos , Apoptose/imunologia , Ascite/imunologia , Ascite/patologia , Linhagem Celular Tumoral , Citocinas/biossíntese , Citocinas/genética , Citocinas/imunologia , Proteína DEAD-box 58 , RNA Helicases DEAD-box/genética , RNA Helicases DEAD-box/imunologia , Células Dendríticas/imunologia , Ativação Enzimática , Feminino , Antígenos de Histocompatibilidade Classe I/biossíntese , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Ligantes , Monócitos/imunologia , Neoplasias Ovarianas/enzimologia , Neoplasias Ovarianas/genética , Poli dA-dT/administração & dosagem , RNA de Cadeia Dupla/administração & dosagem
13.
Am J Respir Cell Mol Biol ; 38(1): 38-46, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17641297

RESUMO

Particle-mediated epidermal delivery (PMED) of allergen genes efficiently prevents systemic sensitization and suppresses specific immunoglobulin E synthesis. We investigated in a mouse model of allergic airway disease the effect of PMED on the elicitation of local inflammatory reactions in the lung. BALB/c mice were biolistically transfected with plasmids encoding beta-galactosidase (betaGal) as model allergen under control of the DC-targeting fascin promoter and the ubiquitously active cytomegalovirus promoter, respectively. Mice were challenged intranasally with betaGal-protein with or without intermediate sensitization with betaGal adsorbed to aluminiumhydroxide. Subsequently, local cytokine production and recruitment of IFN-gamma-producing CD8(+) effector T cells into the airways were determined, and inflammatory parameters such as cellular infiltration in the bronchoalveolar lavage (BAL) and airway hyperresponsiveness (AHR) were measured. PMED of betaGal-encoding plasmids before sensitization significantly reduced frequencies of eosinophils in the BAL and shifted the local T helper (Th) cell response from a distinct Th2 response toward a Th1-biased response. However, AHR triggered by allergen challenge via the airways was not alleviated in vaccinated mice. Most important, we show that PMED using betaGal-encoding DNA without subsequent sensitization recruited Tc1 cells into the lung and caused a Th1-prone local immune response after subsequent intranasal provocation, accompanied by neutrophilic infiltration into the airways and elicitation of AHR. We conclude that robust Th1/Tc1 immune responses, although highly effective in the counter-regulation of local Th2-mediated pathology, might as well trigger local inflammatory reactions in the lung and provoke the induction of AHR in the mouse model of allergic airway disease.


Assuntos
Líquido da Lavagem Broncoalveolar/imunologia , Técnicas de Transferência de Genes , Pulmão/imunologia , Hipersensibilidade Respiratória/imunologia , Células Th1/imunologia , beta-Galactosidase/imunologia , Animais , Formação de Anticorpos/imunologia , Proteínas de Transporte/genética , Células Cultivadas , Citomegalovirus/genética , Células Dendríticas/imunologia , Células Dendríticas/patologia , Modelos Animais de Doenças , Epiderme/imunologia , Epiderme/patologia , Feminino , Humanos , Imunoglobulina E/imunologia , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Interferon gama/imunologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas dos Microfilamentos/genética , Infiltração de Neutrófilos/genética , Infiltração de Neutrófilos/imunologia , Regiões Promotoras Genéticas/genética , Hipersensibilidade Respiratória/genética , Hipersensibilidade Respiratória/patologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/patologia , Células Th1/patologia , Células Th2/imunologia , Células Th2/patologia , beta-Galactosidase/genética
14.
Int Arch Allergy Immunol ; 144(3): 183-96, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17570926

RESUMO

BACKGROUND: Bacterial infections are supposed to act counterregulatory to the development of allergen-specific Th2 immune responses. We analyzed whether administration of extracellular Staphylococcus aureus inhibited experimental sensitization against allergens. METHODS: BALB/c mice were immunized with alum-adsorbed ovalbumin (OVA) together with formalin-fixed Staphylococcus particles. OVA-specific antibody production and cytokine synthesis by spleen cells was analyzed. Airway reactivity and cellular infiltration into the airways was assessed after intranasal challenge of mice with OVA. In addition, the capacity of Staphylococcus particles to modulate cytokine production by bone marrow-derived dendritic cells was analyzed in vitro. RESULTS: Simultaneous application of OVA and Staphylococcus particles very efficiently inhibited production of specific IgE and IgG1 as well as secretion of IL-4 and IL-5 by splenocytes, while enhancing IgG2a formation and production of IFN-gamma, indicating a shift from a Th2 response towards a Th1-biased response. This effect was not dependent on the expression of protein A by Staphylococcus. An enhanced frequency or activity of regulatory T cells after administration of Staphylococcus particles was not apparent. Treatment of mice with Staphylococcus particles during the sensitization phase prevented lung inflammation (airway hyperreactivity, eosinophilia) after local challenge with OVA. Culture of bone marrow-derived dendritic cells with Staphylococcus particles induced IL-12p35 and p40 mRNA expression as well as secretion of IL-12p70, and increased production of IL-10 mRNA and protein. CONCLUSIONS: Administration of formalin-fixed Staphylococcus particles induced Th1-biased immune responses and prevented allergic sensitization.


Assuntos
Fixadores , Formaldeído , Hipersensibilidade/prevenção & controle , Imunização , Staphylococcus aureus/imunologia , Animais , Células Cultivadas , Modelos Animais de Doenças , Feminino , Hipersensibilidade/classificação , Hipersensibilidade/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Material Particulado/imunologia
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