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1.
J Med Virol ; 95(10): e29138, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37796044

RESUMO

The full spectrum of risks for the life course of inactive hepatitis B virus (HBV) carriers remains unclear. In this study, 995 untreated HBV carriers (median age: 42.8 years; median follow-up: 30.2 years) were included. Their data were sourced from a population-based cohort study of male civil servants recruited in 1989-1992. Outcomes were identified by active follow-up examinations and linkage with national health insurance research database. At baseline, 483 subjects were inactive carriers, 385 with indeterminate phase, and 127 with other phases. The joint lifetime risk for incident cirrhosis, decompensation, hepatocellular carcinoma, and liver-related deaths was lower for inactive carriers compared to subjects in other phases (p < 0.0001). There was a trend of increase in incidence among inactive carriers; the 5-, 10-, and 20-year cumulative incidences were 1.86%, 6.03%, and 10.07%, respectively. Of the inactive carriers, 37.7% cleared HBsAg and 36.6% had biochemical relapse during the study. Biochemical relapse, obesity, and advanced age were predictors for disease progression in inactive carriers. Virological relapse was the predominant cause of biochemical relapse. Higher HBV-DNA levels (≥1000 copies/mL or 200 IU/mL) and HBV genotype B (vs. C) were associated with higher virological relapse rate. After 30 years, we found that one-time measure of inactive carrier state continued to have the lowest risk compared with other infection phases. Despite a more favorable prognosis, inactive carriers had a non-negligible risk. Our findings of lifetime risk may provide important clues for the management of such patients and consideration of therapeutic strategies aiming to achieve functional cure.


Assuntos
Hepatite B Crônica , Hepatite B , Neoplasias Hepáticas , Humanos , Masculino , Adulto , Estudos de Coortes , Recidiva Local de Neoplasia , Vírus da Hepatite B/genética , Antígenos de Superfície da Hepatite B , DNA Viral/genética , Neoplasias Hepáticas/epidemiologia , Recidiva , Antígenos E da Hepatite B , Portador Sadio/epidemiologia , Hepatite B/complicações
2.
Clin Mol Hepatol ; 29(3): 705-720, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37157776

RESUMO

BACKGROUND/AIMS: Chronic hepatitis B (CHB) and fatty liver (FL) often co-exist, but natural history data of this dual condition (CHB-FL) are sparse. Via a systematic review, conventional meta-analysis (MA) and individual patient-level data MA (IPDMA), we compared liver-related outcomes and mortality between CHB-FL and CHB-no FL patients. METHODS: We searched 4 databases from inception to December 2021 and pooled study-level estimates using a random- effects model for conventional MA. For IPDMA, we evaluated outcomes after balancing the two study groups with inverse probability treatment weighting (IPTW) on age, sex, cirrhosis, diabetes, ALT, HBeAg, HBV DNA, and antiviral treatment. RESULTS: We screened 2,157 articles and included 19 eligible studies (17,955 patients: 11,908 CHB-no FL; 6,047 CHB-FL) in conventional MA, which found severe heterogeneity (I2=88-95%) and no significant differences in HCC, cirrhosis, mortality, or HBsAg seroclearance incidence (P=0.27-0.93). IPDMA included 13,262 patients: 8,625 CHB-no FL and 4,637 CHB-FL patients who differed in several characteristics. The IPTW cohort included 6,955 CHB-no FL and 3,346 CHB-FL well-matched patients. CHB-FL patients (vs. CHB-no FL) had significantly lower HCC, cirrhosis, mortality and higher HBsAg seroclearance incidence (all p≤0.002), with consistent results in subgroups. CHB-FL diagnosed by liver biopsy had a higher 10-year cumulative HCC incidence than CHB-FL diagnosed with non-invasive methods (63.6% vs. 4.3%, p<0.0001). CONCLUSION: IPDMA data with well-matched CHB patient groups showed that FL (vs. no FL) was associated with significantly lower HCC, cirrhosis, and mortality risk and higher HBsAg seroclearance probability.


Assuntos
Carcinoma Hepatocelular , Fígado Gorduroso , Hepatite B Crônica , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/epidemiologia , Antígenos de Superfície da Hepatite B , Hepatite B Crônica/complicações , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/epidemiologia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/epidemiologia , Vírus da Hepatite B/genética , Antivirais/uso terapêutico , Cirrose Hepática/etiologia , Cirrose Hepática/complicações , Fígado Gorduroso/complicações , DNA Viral/análise
3.
JCI Insight ; 8(3)2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-36538527

RESUMO

Chronic exposure to high-fat diets (HFD) worsens intestinal disease pathology, but acute effects of HFD in tissue damage remain unclear. Here, we used short-term HFD feeding in a model of intestinal injury and found sustained damage with increased cecal dead neutrophil accumulation, along with dietary lipid accumulation. Neutrophil depletion rescued enhanced pathology. Macrophages from HFD-treated mice showed reduced capacity to engulf dead neutrophils. Macrophage clearance of dead neutrophils activates critical barrier repair and antiinflammatory pathways, including IL-10, which was lost after acute HFD feeding and intestinal injury. IL-10 overexpression restored intestinal repair after HFD feeding and intestinal injury. Macrophage exposure to lipids from the HFD prevented tethering and uptake of apoptotic cells and Il10 induction. Milk fat globule-EGF factor 8 (MFGE8) is a bridging molecule that facilitates macrophage uptake of dead cells. MFGE8 also facilitates lipid uptake, and we demonstrate that dietary lipids interfere with MFGE8-mediated macrophage apoptotic neutrophil uptake and subsequent Il10 production. Our findings demonstrate that HFD promotes intestinal pathology by interfering with macrophage clearance of dead neutrophils, leading to unresolved tissue damage.


Assuntos
Dieta Hiperlipídica , Interleucina-10 , Camundongos , Animais , Intestinos , Macrófagos/fisiologia , Lipídeos
4.
Cancers (Basel) ; 14(23)2022 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-36497492

RESUMO

The value of metabolic-associated fatty liver disease (MAFLD) and its ability to assess hepatocellular carcinoma (HCC) risk remains uncertain for chronic hepatitis B (CHB). We evaluated the impacts of MAFLD and its coincidental metabolic abnormalities and related genetic predisposition on HCC incidence and mortality outcomes in CHB. We analyzed data from 1453 HBsAg-positive men (median age = 49.2 years at baseline) from a cohort of civil servants recruited from 1989−1992. MAFLD was defined as hepatic steatosis on ultrasound with obesity, diabetes, or metabolic dysfunction at baseline. During follow-up (median = 19.3 years), 105 HCC events occurred. MAFLD was not associated with HCC (adjusted hazard ratio (aHR) = 1.02) but was associated with a higher HBsAg seroclearance rate (aHR = 1.43). In mediation analysis, HBsAg seroclearance driven by hepatic steatosis explained 31.6% of the association between MAFLD and HCC. Antiviral treatment or fatty liver disease-associated genetic variants did not influence the MAFLD−HCC association. In contrast, even after adjustment for MAFLD and the other metabolic abnormalities, diabetes (aHR = 2.28), obesity (aHR = 1.72), and metabolic dysfunction (aHR = 3.30) increased the risk of HCC (all p < 0.030). The risk of HCC increased with the number of metabolic abnormalities (vs 0: aHR = 2.05 and 5.72 for 2 and ≥ 3 metabolic abnormalities, respectively), and the cumulative effect of metabolic abnormalities was found across subgroups categorized by hepatic steatosis as well as in participants both with and without HBsAg seroclearance. In conclusion, MAFLD was not associated with increased HCC incidence in CHB. A more informative assessment of HCC risk can be obtained by taking into account the number of metabolic abnormalities.

5.
J Hepatocell Carcinoma ; 9: 301-313, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35433529

RESUMO

Background: Coexistence of hepatitis B and nonalcoholic fatty liver disease is common; however, little is known about the impact of hepatic steatosis and its major genetic determinants on the natural history of HBV infection. We aimed to study the effects of hepatic steatosis and PNPLA3 variant p.I148M on the risk of hepatocellular carcinoma (HCC) and the lifetime probability of HBsAg seroclearance, which is associated with functional remission and improved long-term outcome of HBV infection. Methods: We conducted a cohort study of 2385 male, HBsAg-positive Taiwanese civil servants recruited in 1989-1992, and followed up until 2019. Cox regression with competing-risk models was used to estimate sub-distribution hazard ratios (sHRs) and 95% confidence intervals (CIs). Results: Of 2385 participants, 628 experienced HBsAg seroclearance and 217 developed HCC. Hepatic steatosis, excess body-mass index, and the PNPLA3-148M variant were significantly associated with higher HBsAg seroclearance rate. However, multivariate analyses accounting for HBsAg seroclearance and various HCC risk factors showed that, while steatosis was associated with decreased HCC risk (sHR [95% CI]: 0.49 [0.36-0.66]), carriage of the PNPLA3-148M variant allele (vs II homozygotes: 1.64 [1.20-2.25] for MI heterozygotes; 1.83 [1.20-2.78] for MM homozygotes) and obesity (1.51 [1.07-2.13]) were associated with increased risk. The inverse hepatic steatosis-HCC association persisted after additional adjustment for other viral factors or using different follow-up time cut-offs to account for reverse causality. Moreover, the PNPLA3 MM genotype was positively associated with elevations of ALT and AST and liver cirrhosis, while hepatic steatosis was positively associated with ALT but inversely associated with AST and liver cirrhosis. Conclusion: Hepatic steatosis and PNPLA3-148M variant appeared to have distinct impacts on the development of HBV-related progressive liver disease and HCC. PNPLA3 p.I148M, but not a diagnosis of hepatic steatosis, can help to identify HBV carriers with high-risk fatty liver disease in the progression to HCC.

6.
Gut Microbes ; 14(1): 2014772, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34989321

RESUMO

The gut microbiota is essential for maintenance and repair of the intestinal epithelial barrier. As shifts in both intestinal epithelial barrier function and microbiota composition are found in inflammatory bowel disease patients, it is critical to understand the role of distinct bacteria in regulating barrier repair. We identified a mouse commensal E. coli isolate, GDAR2-2, that protects mice from Citrobacter rodentium infection and dextran sulfate sodium-induced colitis. Colonization with GDAR2-2 in mice resulted in expansion of CX3CR1+ mononuclear phagocytes, including CX3CR1+ macrophages/dendritic cells and monocytes, along with IL-22-secreting type 3 innate lymphoid cells and improved epithelial barrier function. In vitro co-culture of macrophages with GDAR2-2 resulted in IL-1ß production. In vivo, protection after GDAR2-2 colonization was lost after depletion of CX3CR1+ MNPs, or blockade of IL-1ß or IL-22. We further identified human commensal E. coli isolates that similarly protect mice from C. rodentium infection through CX3CR1+ MNP and IL-1ß production. Together, these findings demonstrate an unexpected role for commensal bacteria in promoting IL-1ß secretion to support intestinal barrier repair.


Assuntos
Colite/metabolismo , Colite/fisiopatologia , Microbioma Gastrointestinal , Interleucina-18/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Simbiose , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Fenômenos Fisiológicos Bacterianos , Colite/genética , Colite/microbiologia , Humanos , Interleucina-18/genética , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL
7.
J Formos Med Assoc ; 121(8): 1478-1487, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34764005

RESUMO

BACKGROUND: Chronic hepatitis B (CHB) was associated with a lower prevalence of nonalcoholic fatty liver disease (NAFLD). The impact of CHB on the link between NAFLD and type 2 diabetes (T2D) and related virological implications remain unclear. METHODS: We recruited 2255 middle-to older-aged individuals who were examined serially for hepatic steatosis by ultrasonography and blood biochemistry as part of a population-based hepatocellular-carcinoma cohort study. In CHB patients, hepatitis B surface antigen (HBsAg) seroclearance and variation in viral load trajectory were also evaluated. RESULTS: During the average follow-up of 6 years, 168 participants developed T2D. CHB, as compared with uninfected subjects, was associated with lower risks for both new development and persistence of hepatic steatosis. Furthermore, the risk of steatosis decreased with higher levels of past viral load trajectories (p for trend = 0.0002). However, concomitant steatosis at baseline in CHB patients was still significantly associated with a 1.98-fold increased risk for T2D after multivariate adjustment including age, impaired fasting glucose, cirrhosis, and time-varying body mass index, although CHB reduced the propensity of hepatic steatosis to develop diabetes, especially for patients with high levels of past viral-load trajectory. In CHB, the functional cure of HBV infection, as indicated by HBsAg seroclearance, was associated with a 1.41-fold (95% CI 1.12-1.79) increased risk of steatosis. In addition, the increased risk for progressive impairment of glucose metabolism due to steatosis was especially prominent after HBsAg seroclearance. CONCLUSION: The data showed that HBV interferes with fatty liver disease and modulates its related T2D risk, offering additional insight into the interplay between NAFLD and CHB.


Assuntos
Diabetes Mellitus Tipo 2 , Hepatite B Crônica , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Estudos de Coortes , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Antígenos de Superfície da Hepatite B , Vírus da Hepatite B , Hepatite B Crônica/complicações , Hepatite B Crônica/epidemiologia , Humanos , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/etiologia , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/epidemiologia
8.
Nature ; 594(7863): 413-417, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33981034

RESUMO

Humans and their microbiota have coevolved a mutually beneficial relationship in which the human host provides a hospitable environment for the microorganisms and the microbiota provides many advantages for the host, including nutritional benefits and protection from pathogen infection1. Maintaining this relationship requires a careful immune balance to contain commensal microorganisms within the lumen while limiting inflammatory anti-commensal responses1,2. Antigen-specific recognition of intestinal microorganisms by T cells has previously been described3,4. Although the local environment shapes the differentiation of effector cells3-5 it is unclear how microbiota-specific T cells are educated in the thymus. Here we show that intestinal colonization in early life leads to the trafficking of microbial antigens from the intestine to the thymus by intestinal dendritic cells, which then induce the expansion of microbiota-specific T cells. Once in the periphery, microbiota-specific T cells have pathogenic potential or can protect against related pathogens. In this way, the developing microbiota shapes and expands the thymic and peripheral T cell repertoire, allowing for enhanced recognition of intestinal microorganisms and pathogens.


Assuntos
Células Dendríticas/imunologia , Microbioma Gastrointestinal/imunologia , Linfócitos T/citologia , Linfócitos T/imunologia , Timo/citologia , Timo/imunologia , Envelhecimento/imunologia , Animais , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/metabolismo , Receptor 1 de Quimiocina CX3C/metabolismo , DNA Bacteriano/análise , Células Dendríticas/metabolismo , Escherichia coli/imunologia , Feminino , Masculino , Camundongos , Especificidade de Órgãos , Salmonella/imunologia , Simbiose/imunologia , Timo/metabolismo
9.
Mol Carcinog ; 59(11): 1269-1279, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32914490

RESUMO

Despite considerable knowledge of viral pathogenesis, the pathophysiological changes related to the multifactorial, multistep process of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) development remains unclear. Longitudinal metabolomics study can reveal biological process for disease progression. We performed metabolite profiling with longitudinal prediagnostic plasma samples from two nested case-control studies of hepatitis B surface antigen carriers participating in ultrasound screening for HCC, one within a government employee cohort (870 samples from 109 HCC cases and 107 controls) and the other within a hospital-based cohort (266 samples from 63 HCC cases and 114 controls). Of the 34 measured metabolites, tyrosine, isoleucine, and glutamine were consistently associated with HCC. In analyses combining longitudinal data, a high metabolic risk score based on the three amino acids was robustly associated with increased risk of HCC (OR = 3.71, 95% confidence interval: 2.53-5.42), even after adjustment for clinical factors, or when assessed for different times up to ≥8 years before diagnosis. Similar association was observed in an independent, prospective analysis comprising 633 randomly selected individuals of the government employee cohort. More importantly, this metabolite signature was longitudinally influenced by HBV-infection phase and involved in gradual progression to liver fibrosis and cirrhosis. Furthermore, mediation analysis showed that the score mediated substantial proportions of the associations of key viral factors, insulin resistance, and diabetes status with HCC risk. Our results suggest that an amino-acid dysregulation metabotype may play a role in HBV-related HCC development, and may also be linked to common pathways that mediate increased HCC risks.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Metaboloma , Adulto , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/metabolismo , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/metabolismo , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida
10.
Front Immunol ; 11: 597966, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33424846

RESUMO

Autoimmune diseases and chronic inflammatory disorders are characterized by dysregulated immune responses resulting in excessive and uncontrolled tissue inflammation. Multiple factors including genetic variation, environmental stimuli, and infection are all thought to contribute to continued inflammation and pathology. Current evidence supports the microbiota as one such factor with emerging data linking commensal organisms to the onset and progression of disease. In this review, we will discuss links between the microbiota and specific diseases as well as highlight common pathways that link intestinal microbes with multiple autoimmune and inflammatory diseases.


Assuntos
Doenças Autoimunes/etiologia , Autoimunidade , Suscetibilidade a Doenças , Microbioma Gastrointestinal , Inflamação/etiologia , Animais , Autoanticorpos/imunologia , Doenças Autoimunes/diagnóstico , Doenças Autoimunes/metabolismo , Suscetibilidade a Doenças/imunologia , Disbiose/imunologia , Microbioma Gastrointestinal/imunologia , Humanos , Inflamação/diagnóstico , Inflamação/metabolismo , Especificidade de Órgãos/imunologia
11.
Front Immunol ; 10: 75, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30761142

RESUMO

Epidemiological evidence finds cigarette smoking is a common risk factor for a number of diseases, not only in the lung but also in other tissues, such as the gastrointestinal tract. While it is well-documented that smoking directly drives lung inflammatory disease, how it promotes disease in peripheral tissues is incompletely understood. In this study, we utilized a mouse model of short-term smoke exposure and found increased Th17 cells and neutrophilia in the lung as well as in the circulation. Following intestinal inflammatory challenge, smoke exposed mice showed increased pathology which corresponds to enhanced intestinal Th17 cells, ILC3 and neutrophils within intestinal tissue. Using cellular depletion and genetic deficiencies, we define a cellular loop by which IL-17A and downstream neutrophils drive cigarette smoke-enhanced intestinal inflammation. Collectively, cigarette smoke induced local lung Th17 responses lead to increased systemic susceptibility to inflammatory insult through enhanced circulating neutrophils. These data demonstrate a cellular pathway by which inflammatory challenge in the lung can sensitize the intestine to enhanced pathological innate and adaptive immune responses.


Assuntos
Intestinos/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Fumaça/efeitos adversos , Células Th17/efeitos dos fármacos , Produtos do Tabaco , Animais , Colite/induzido quimicamente , Colite/imunologia , Colite/patologia , Citocinas/genética , Citocinas/imunologia , Feminino , Intestinos/imunologia , Intestinos/patologia , Pulmão/imunologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neutrófilos/imunologia , Células Th17/imunologia
12.
Hepatology ; 69(4): 1412-1425, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30382583

RESUMO

Smoking interacts with hepatitis B virus (HBV) to increase the risk of hepatocellular carcinoma (HCC), which might be explained by its role in antiviral immunity. We evaluated the potential mediating role of viral load and/or alanine aminotransferase (ALT) in the relation of smoking with HBV-associated HCC risk. Using multiple mediation analyses to analyze data from 209 HCC cases and 1,256 controls nested within a cohort of 4,841 male HBV carriers, we found that the effect of smoking on the risk of subsequent HCC was substantially mediated through viral load (percent mediated, 31.7%; P = 0.0054), and a significant mediation effect by both viral load and ALT was also evidenced. Among the 1,143 subjects with repeated measures of viral load and ALT over periods of up to 16 years, we further observed that a higher number of pack-years of smoking was associated with higher viral load, maintenance of a high viral load (>4.39 log copies/mL), more severe hepatotoxicity grade, and increased likelihood of ALT ≥80 U/L (odds ratio, 3.14; 95% confidence interval, 1.03-9.64; odds ratio, 6.06; 95% confidence interval, 1.10-33.25, respectively, for 10-19 and ≥20 pack-years versus nonsmokers) during follow-up. Furthermore, plasma interferon-γ levels were reduced in smokers compared with nonsmokers (interferon-γ-positive rate, 14.9% versus 28.7%; P < 0.0001) at baseline. Smoking was also associated with a reduced natural killer (NK) cell frequency in peripheral blood, characterized by reduced NK function through a systems immunology approach, after long-term follow-up in a subsample (n = 171). The combination of smoking and reduced NK cell frequency further increased viral load and the likelihood of ALT ≥80 U/L. Conclusion: The data highlight a role of smoking in HBV viral load, underlining the importance of smoking prevention and cessation in hepatitis B management.


Assuntos
Alanina Transaminase/sangue , Carcinoma Hepatocelular/virologia , Hepatite B/complicações , Neoplasias Hepáticas/virologia , Fumar/efeitos adversos , Adulto , Carcinoma Hepatocelular/sangue , Estudos de Casos e Controles , Estudos de Coortes , Humanos , Células Matadoras Naturais , Neoplasias Hepáticas/sangue , Masculino , Pessoa de Meia-Idade , Fumar/imunologia , Carga Viral
13.
Gut Microbes ; 10(4): 540-546, 2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-33970784

RESUMO

Intestinal damage driven by unrestricted immune responses against the intestinal microbiota can lead to the development of inflammatory diseases including inflammatory bowel disease. How such breakdown in tolerance occurs alongside the mechanisms to reinforce homeostasis with the microbiota are a focus of many studies. Our recent work demonstrates coordinated interactions between intact microbiota and CX3CR1 expressing intestinal antigen presenting cells (APCs) that limits T helper 1 cell responses and promotes differentiation of regulatory T cells (Treg) against intestinal antigens including pathogens, soluble proteins and the microbiota itself. We find a microbial attachment to intestinal epithelial cells is necessary to support these anti-inflammatory immune functions. In this addendum, we discuss how our findings enhance understanding of microbiota-directed homeostatic functions of the intestinal immune system and implications of modulating this interaction in ameliorating inflammatory disease.

14.
Immunity ; 49(1): 151-163.e5, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-29980437

RESUMO

The intestinal barrier is vulnerable to damage by microbiota-induced inflammation that is normally restrained through mechanisms promoting homeostasis. Such disruptions contribute to autoimmune and inflammatory diseases including inflammatory bowel disease. We identified a regulatory loop whereby, in the presence of the normal microbiota, intestinal antigen-presenting cells (APCs) expressing the chemokine receptor CX3CR1 reduced expansion of intestinal microbe-specific T helper 1 (Th1) cells and promoted generation of regulatory T cells responsive to food antigens and the microbiota itself. We identified that disruption of the microbiota resulted in CX3CR1+ APC-dependent inflammatory Th1 cell responses with increased pathology after pathogen infection. Colonization with microbes that can adhere to the epithelium was able to compensate for intestinal microbiota loss, indicating that although microbial interactions with the epithelium can be pathogenic, they can also activate homeostatic regulatory mechanisms. Our results identify a cellular mechanism by which the microbiota limits intestinal inflammation and promotes tissue homeostasis.


Assuntos
Receptor 1 de Quimiocina CX3C/metabolismo , Microbioma Gastrointestinal/imunologia , Mucosa Intestinal/imunologia , Sistema Fagocitário Mononuclear/imunologia , Linfócitos T Reguladores/imunologia , Células Th1/imunologia , Animais , Apresentação de Antígeno , Aderência Bacteriana/imunologia , Modelos Animais de Doenças , Feminino , Homeostase , Tolerância Imunológica , Imunidade nas Mucosas , Inflamação/imunologia , Doenças Inflamatórias Intestinais/imunologia , Interleucina-10/imunologia , Interleucina-10/metabolismo , Mucosa Intestinal/microbiologia , Masculino , Camundongos , Células RAW 264.7
15.
Dis Aquat Organ ; 74(3): 171-8, 2007 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-17465302

RESUMO

White spot syndrome virus (WSSV) is the causative agent of a severe disease of cultivated shrimp. Using purified WSSV virions, VP53A encoded by open reading frame wssv067 was identified as a structural protein by SDS-PAGE and proteomics. Immunoelectron microscopy with a gold-labeled secondary antibody revealed that VP53A was distributed on the viral envelope. In order to further explore the link between WSSV067 and host proteins, we performed a yeast 2-hybrid screening of a Penaeus monodon cDNA library, using WSSV067C as bait. One of the molecules that specifically interacted with WSSV067C was the P. monodon chitin-binding protein (PmCBP). An in vitro binding assay showed that c-myc-WSSV067C was capable of co-precipitating HA-PmCBP-C. Furthermore, PmCBP was expressed in almost all organs but appeared to be up-regulated at the late stage of WSSV infection.


Assuntos
Proteínas de Transporte/metabolismo , Quitina/metabolismo , Penaeidae/virologia , Proteínas do Envelope Viral/metabolismo , Vírus da Síndrome da Mancha Branca 1/patogenicidade , Sequência de Aminoácidos , Animais , Anticorpos Antivirais/metabolismo , Sequência de Bases , Proteínas de Transporte/química , Proteínas de Transporte/genética , DNA Complementar/química , Eletroforese em Gel de Poliacrilamida , Perfilação da Expressão Gênica , Regulação Viral da Expressão Gênica/fisiologia , Imunoprecipitação , Microscopia Imunoeletrônica , Dados de Sequência Molecular , Penaeidae/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saccharomyces cerevisiae , Fatores de Tempo , Proteínas do Envelope Viral/genética , Vírus da Síndrome da Mancha Branca 1/genética , Vírus da Síndrome da Mancha Branca 1/metabolismo
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