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Helicobacter hepaticus

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https://www.readbyqxmd.com/read/29414937/c-maf-dependent-regulatory-t-cells-mediate-immunological-tolerance-to-a-gut-pathobiont
#1
Mo Xu, Maria Pokrovskii, Yi Ding, Ren Yi, Christy Au, Oliver J Harrison, Carolina Galan, Yasmine Belkaid, Richard Bonneau, Dan R Littman
Both microbial and host genetic factors contribute to the pathogenesis of autoimmune diseases. There is accumulating evidence that microbial species that potentiate chronic inflammation, as in inflammatory bowel disease, often also colonize healthy individuals. These microorganisms, including the Helicobacter species, can induce pathogenic T cells and are collectively referred to as pathobionts. However, how such T cells are constrained in healthy individuals is not yet understood. Here we report that host tolerance to a potentially pathogenic bacterium, Helicobacter hepaticus, is mediated by the induction of RORγt+FOXP3+ regulatory T (iTreg) cells that selectively restrain pro-inflammatory T helper 17 (TH17) cells and whose function is dependent on the transcription factor c-MAF...
February 7, 2018: Nature
https://www.readbyqxmd.com/read/29361512/environmental-factors-regulate-paneth-cell-phenotype-and-host-susceptibility-to-intestinal-inflammation-in-irgm1-deficient-mice
#2
Allison R Rogala, Alexi A Schoenborn, Brian E Fee, Viviana A Cantillana, Maria J Joyce, Raad Z Gharaibeh, Sayanty Roy, Anthony A Fodor, R Balfour Sartor, Gregory A Taylor, Ajay S Gulati
Crohn's disease (CD) represents a chronic inflammatory disorder of the intestinal tract. Several susceptibility genes have been linked to CD, though their precise role in the pathogenesis of this disorder remains unclear. Immunity-Related GTPase M (IRGM) is an established CD risk allele. We have shown previously that conventionally-raised (CV) mice lacking the IRGM ortholog, Irgm1, exhibit abnormal Paneth cells (PCs) and increased susceptibility to intestinal injury. In the present study, we sought to utilize this model system to determine if environmental conditions impact these phenotypes, as is thought to be the case in human CD...
December 22, 2017: Disease Models & Mechanisms
https://www.readbyqxmd.com/read/29358084/intestinal-epithelial-cell-autophagy-is-required-to-protect-against-tnf-induced-apoptosis-during-chronic-colitis-in-mice
#3
Johanna Pott, Agnieszka Martyna Kabat, Kevin Joseph Maloy
Genome-wide association studies have linked polymorphisms in the autophagy gene ATG16L1 with susceptibility to inflammatory bowel disease (IBD). However, the cell-type-specific effects of autophagy on the regulation of chronic intestinal inflammation have not been investigated. Here, we assessed the effect of myeloid-specific or intestinal epithelial cell (IEC)-specific deletion of Atg16l1 on chronic colitis triggered by the intestinal opportunistic pathogen Helicobacter hepaticus in mice. Although Atg16l1 deficiency in myeloid cells had little effect on disease, mice selectively lacking Atg16l1 in IECs (Atg16l1VC) developed severely exacerbated pathology, accompanied by elevated pro-inflammatory cytokine secretion and increased IEC apoptosis...
January 17, 2018: Cell Host & Microbe
https://www.readbyqxmd.com/read/29241040/a-large-polysaccharide-produced-by-helicobacter-hepaticus-induces-an-anti-inflammatory-gene-signature-in-macrophages
#4
Camille Danne, Grigory Ryzhakov, Maria Martínez-López, Nicholas Edward Ilott, Fanny Franchini, Fiona Cuskin, Elisabeth C Lowe, Samuel J Bullers, J Simon C Arthur, Fiona Powrie
Interactions between the host and its microbiota are of mutual benefit and promote health. Complex molecular pathways underlie this dialog, but the identity of microbe-derived molecules that mediate the mutualistic state remains elusive. Helicobacter hepaticus is a member of the mouse intestinal microbiota that is tolerated by the host. In the absence of an intact IL-10 signaling, H. hepaticus induces an IL-23-driven inflammatory response in the intestine. Here we investigate the interactions between H. hepaticus and host immune cells that may promote mutualism, and the microbe-derived molecule(s) involved...
December 13, 2017: Cell Host & Microbe
https://www.readbyqxmd.com/read/29241034/sweet-helicobacter-sugar-calms-intestinal-macrophages
#5
Calum C Bain, Marika C Kullberg
In the absence of IL-10, Helicobacter hepaticus (Hh) induces colitis. In this issue of Cell Host & Microbe, Danne et al. (2017) report that Hh produces a polysaccharide that induces an anti-inflammatory response in macrophages, providing a potential clue as to why this bacterium is normally tolerated by the immune system.
December 13, 2017: Cell Host & Microbe
https://www.readbyqxmd.com/read/29203542/pro-inflammatory-role-of-monocyte-derived-cx3cr1int-macrophages-in-helicobacter-hepaticus-induced-colitis
#6
Calum C Bain, Christopher J Oliphant, Carolyn A Thomson, Marika C Kullberg, Allan McI Mowat
Cells of the monocyte-macrophage lineage play important roles in the pathogenesis of inflammatory bowel diseases, but they are also present in the normal healthy intestine, where they are critical for maintaining homeostasis. It has been unclear whether the pro-inflammatory roles of intestinal macrophages reflect altered behaviour of the existing resident cells, or if they involve recruitment of a distinct cell type. Here we have explored these ideas using the model of colitis induced by Helicobacter hepaticus (Hh) in the context of neutralisation or deletion of interleukin 10 (IL-10)...
December 4, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28951889/functional-changes-in-the-gut-microbiome-contribute-to-transforming-growth-factor-%C3%AE-deficient-colon-cancer
#7
Scott G Daniel, Corbie L Ball, David G Besselsen, Tom Doetschman, Bonnie L Hurwitz
Colorectal cancer (CRC) is one of the most treatable cancers, with a 5-year survival rate of ~64%, yet over 50,000 deaths occur yearly in the United States. In 15% of cases, deficiency in mismatch repair leads to null mutations in transforming growth factor β (TGF-β) type II receptor, yet genotype alone is not responsible for tumorigenesis. Previous work in mice shows that disruptions in TGF-β signaling combined with Helicobacter hepaticus cause tumorigenesis, indicating a synergistic effect between genotype and microbial environment...
September 2017: MSystems
https://www.readbyqxmd.com/read/28713773/the-cytolethal-distending-toxin-subunit-cdtb-of-helicobacter-hepaticus-promotes-senescence-and-endoreplication-in-xenograft-mouse-models-of-hepatic-and-intestinal-cell-lines
#8
Christelle Péré-Védrenne, Martina Prochazkova-Carlotti, Benoit Rousseau, Wencan He, Lucie Chambonnier, Elodie Sifré, Alice Buissonnière, Pierre Dubus, Francis Mégraud, Christine Varon, Armelle Ménard
Cytolethal distending toxins (CDTs) are common among pathogenic bacteria of the human and animal microbiota. CDTs exert cytopathic effets, via their active CdtB subunit. No clear description of those cytopathic effects has been reported at the cellular level in the target organs in vivo. In the present study, xenograft mouse models of colon and liver cell lines were set up to study the effects of the CdtB subunit of Helicobacter hepaticus. Conditional transgenic cell lines were established, validated in vitro and then engrafted into immunodeficient mice...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/28198364/interleukin-22-drives-nitric-oxide-dependent-dna-damage-and-dysplasia-in-a-murine-model-of-colitis-associated-cancer
#9
C Wang, G Gong, A Sheh, S Muthupalani, E M Bryant, D A Puglisi, H Holcombe, E A Conaway, N A P Parry, V Bakthavatchalu, S P Short, C S Williams, G N Wogan, S R Tannenbaum, J G Fox, B H Horwitz
The risk of colon cancer is increased in patients with Crohn's disease and ulcerative colitis. Inflammation-induced DNA damage could be an important link between inflammation and cancer, although the pathways that link inflammation and DNA damage are incompletely defined. RAG2-deficient mice infected with Helicobacter hepaticus (Hh) develop colitis that progresses to lower bowel cancer. This process depends on nitric oxide (NO), a molecule with known mutagenic potential. We have previously hypothesized that production of NO by macrophages could be essential for Hh-driven carcinogenesis, however, whether Hh infection induces DNA damage in this model and whether this depends on NO has not been determined...
November 2017: Mucosal Immunology
https://www.readbyqxmd.com/read/28145441/colonization-with-helicobacter-is-concomitant-with-modified-gut-microbiota-and-drastic-failure-of-the-immune-control-of-mycobacterium-tuberculosis
#10
L Majlessi, F Sayes, J-F Bureau, A Pawlik, V Michel, G Jouvion, M Huerre, M Severgnini, C Consolandi, C Peano, R Brosch, E Touati, C Leclerc
Epidemiological and experimental observations suggest that chronic microbial colonization can impact the immune control of other unrelated pathogens contracted in a concomitant or sequential manner. Possible interactions between Mycobacterium tuberculosis infection and persistence of other bacteria have scarcely been investigated. Here we demonstrated that natural colonization of the digestive tract with Helicobacter hepaticus in mice is concomitant with modification of the gut microbiota, subclinical inflammation, and drastic impairment of immune control of the growth of subsequently administered M...
September 2017: Mucosal Immunology
https://www.readbyqxmd.com/read/28111881/helicobacter-hepaticus-cytolethal-distending-toxin-promotes-intestinal-carcinogenesis-in-129rag2-deficient-mice
#11
Zhongming Ge, Yan Feng, Lili Ge, Nicola Parry, Sureshkumar Muthupalani, James G Fox
Multiple pathogenic Gram-negative bacteria produce the cytolethal distending toxin (CDT) with activity of DNase I; CDT can induce DNA double-strand breaks (DSBs), G2/M cell cycle arrest, and apoptosis in cultured mammalian cells. However, the link of CDT to in vivo tumorigenesis is not fully understood. In this study, 129/SvEv Rag2-/- mice were gavaged with wild-type Helicobacter hepatics 3B1(Hh) and its isogenic cdtB mutant HhcdtBm7, followed by infection for 10 and 20 weeks (WPI). HhCDT deficiency did not affect cecal colonization levels of HhcdtBm7, but attenuated severity of cecal pathology in HhcdtBm7-infected mice...
July 2017: Cellular Microbiology
https://www.readbyqxmd.com/read/27895587/vitamin-d-signaling-through-induction-of-paneth-cell-defensins-maintains-gut-microbiota-and-improves-metabolic-disorders-and-hepatic-steatosis-in-animal-models
#12
Danmei Su, Yuanyang Nie, Airu Zhu, Zishuo Chen, Pengfei Wu, Li Zhang, Mei Luo, Qun Sun, Linbi Cai, Yuchen Lai, Zhixiong Xiao, Zhongping Duan, Sujun Zheng, Guihui Wu, Richard Hu, Hidekazu Tsukamoto, Aurelia Lugea, Zhenqui Liu, Stephen J Pandol, Yuan-Ping Han
Metabolic syndrome (MetS), characterized as obesity, insulin resistance, and non-alcoholic fatty liver diseases (NAFLD), is associated with vitamin D insufficiency/deficiency in epidemiological studies, while the underlying mechanism is poorly addressed. On the other hand, disorder of gut microbiota, namely dysbiosis, is known to cause MetS and NAFLD. It is also known that systemic inflammation blocks insulin signaling pathways, leading to insulin resistance and glucose intolerance, which are the driving force for hepatic steatosis...
2016: Frontiers in Physiology
https://www.readbyqxmd.com/read/27746159/modulation-of-host-defence-against-bacterial-and-viral-infections-by-omega-3-polyunsaturated-fatty-acids
#13
REVIEW
Marie-Odile Husson, Delphine Ley, Céline Portal, Madeleine Gottrand, Thomas Hueso, Jean-Luc Desseyn, Frédéric Gottrand
OBJECTIVES: Although n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFAs) are used widely in the treatment of chronic inflammatory diseases, their effect in infectious disease requires a particular attention. METHODS: The present article discusses their anti-inflammatory and immune properties involved in the host defence and presents a systematic review of the effects of their oral administration on the prevention and outcome of experimental and clinical infections...
December 2016: Journal of Infection
https://www.readbyqxmd.com/read/27687595/differentiation-of-five-enterohepatic-helicobacter-species-by-nested-pcr-with-high-resolution-melting-curve-analysis
#14
Miaoli Wu, Dan Rao, Yujun Zhu, Jing Wang, Wen Yuan, Yu Zhang, Ren Huang, Pengju Guo
BACKGROUND: Enterohepatic Helicobacter species (EHS) are widespread in rodent species around the world. Several studies have demonstrated that infection with EHS can interfere with the outcomes of animal experiments in cancer research and significantly influence the study results. Therefore, it is essential to establish a rapid detection and identification of EHS for biomedical research using laboratory rodents. Our study aimed to develop a rapid and sensitive method to detect and distinguish five enterohepatic Helicobacter species...
April 2017: Helicobacter
https://www.readbyqxmd.com/read/27275113/diagnosis-of-genus-helicobacter-through-a-hemi-nested-pcr-assay-of-16s-rrna
#15
Heping Qin, Guodu Tang, Ping Yi, Xinyi Pan, Huali Huang, Renjie Chang, Zhe Shi, Muhammad Aqeel Ashraf
The present study aimed to establish a genus-specific PCR-based assay to detect helicobacters using 16S rRNA gene as the target template. We designed the hemi-nested primers based on sequences of 16S rRNA gene of 34 types of Helicobacter species. The inclusivity, sensitivity, and specificity of the PCR assay using these primers were examined in three different models, comprising feces simulated samples, BLAB/c mice infection model and clinic patients samples. The detection sensitivity of Helicobacter pylori, Helicobacter hepaticus and Helicobacter bilis strains from feces simulated samples was all 102 CFU/ml...
May 2016: Saudi Pharmaceutical Journal: SPJ: the Official Publication of the Saudi Pharmaceutical Society
https://www.readbyqxmd.com/read/27183623/tbet-or-continued-ror%C3%AE-t-expression-is-not-required-for-th17-associated-immunopathology
#16
Verena Brucklacher-Waldert, Cristina Ferreira, Silvia Innocentin, Shraddha Kamdar, David R Withers, Marika C Kullberg, Marc Veldhoen
The discovery of Th17 cell plasticity, in which CD4(+) IL-17-producing Th17 cells give rise to IL-17/IFN-γ double-producing cells and Th1-like IFNγ(+) ex-Th17 lymphocytes, has raised questions regarding which of these cell types contribute to immunopathology during inflammatory diseases. In this study, we show using Helicobacter hepaticus-induced intestinal inflammation that IL-17A(Cre)- or Rag1(Cre)-mediated deletion of Tbx21 has no effect on the generation of IL-17/IFN-γ double-producing cells, but leads to a marked absence of Th1-like IFNγ(+) ex-Th17 cells...
June 15, 2016: Journal of Immunology: Official Journal of the American Association of Immunologists
https://www.readbyqxmd.com/read/27027442/il-10-control-of-cd11c-myeloid-cells-is-essential-to-maintain-immune-homeostasis-in-the-small-and-large-intestine
#17
Mathilde J H Girard-Madoux, Juliane L Ober-Blöbaum, Léa M M Costes, Junda M Kel, Dicky J Lindenbergh-Kortleve, Inge Brouwers-Haspels, Astrid P Heikema, Janneke N Samsom, Björn E Clausen
Although IL-10 promotes a regulatory phenotype of CD11c+ dendritic cells and macrophages in vitro, the role of IL-10 signaling in CD11c+ cells to maintain intestinal tolerance in vivo remains elusive. To this aim, we generated mice with a CD11c-specific deletion of the IL-10 receptor alpha (Cd11ccreIl10rafl/fl). In contrast to the colon, the small intestine of Cd11ccreIl10rafl/fl mice exhibited spontaneous crypt hyperplasia, increased numbers of intraepithelial lymphocytes and lamina propria T cells, associated with elevated levels of T cell-derived IFNγ and IL-17A...
May 31, 2016: Oncotarget
https://www.readbyqxmd.com/read/26908757/the-cytolethal-distending-toxin-subunit-cdtb-of-helicobacter-induces-a-th17-related-and-antimicrobial-signature-in-intestinal-and-hepatic-cells-in-vitro
#18
Christelle Péré-Védrenne, Bruno Cardinaud, Christine Varon, Iulia Mocan, Alice Buissonnière, Julien Izotte, Francis Mégraud, Armelle Ménard
Enterohepatic Helicobacter species are associated with several digestive diseases. Helicobacter pullorum is an emerging human foodborne pathogen, and Helicobacter hepaticus is a mouse pathogen; both species are associated with intestinal and/or hepatic diseases. They possess virulence factors, such as cytolethal distending toxin (CDT). Data indicate that CDT may be involved in chronic inflammatory responses, via its active subunit, CdtB. The proinflammatory properties of the CdtB of H. pullorum and H. hepaticus were assessed on human intestinal and hepatic epithelial cells in vitro...
June 15, 2016: Journal of Infectious Diseases
https://www.readbyqxmd.com/read/26883725/t-bet-expression-by-th-cells-promotes-type-1-inflammation-but-is-dispensable-for-colitis
#19
J Zimmermann, A A Kühl, M Weber, J R Grün, J Löffler, C Haftmann, R Riedel, P Maschmeyer, K Lehmann, K Westendorf, M-F Mashreghi, M Löhning, M Mack, A Radbruch, H D Chang
The transcription factor T-bet is highly expressed by Th cells isolated from the inflamed intestine of Crohn's disease patients, and has been regarded a critical driver of murine T cell-induced colitis. However, we show here that T-bet expression by Th cells is not required for the manifestation of T-cell-induced colitis in the presence of segmented filamentous bacteria and Helicobacter hepaticus. T-bet expression by Th cells controls their survival and localization, their repertoire of chemokine and chemokine receptor expression, the accumulation of monocytes and macrophages in the inflamed colon, and their differentiation to the M1 type, i...
November 2016: Mucosal Immunology
https://www.readbyqxmd.com/read/26838240/helicobacter-species-are-possible-risk-factors-of-cholangiocarcinoma
#20
REVIEW
Soraya J Kaewpitoon, Ryan A Loyd, Ratana Rujirakul, Sukij Panpimanmas, Likit Matrakool, Taweesak Tongtawee, Nusorn Kootanavanichpong, Prasit Pengsaa, Ponthip Kompor, Wasugree Chavengkun, Jirawoot Kujapun, Jun Norkaew, Sukanya Ponphimai, Natnapa Padchasuwan, Poowadol Polsripradist, Thawatchai Eksanti, Tanida Phatisena, Natthawut Kaewpitoon
Several infectious agents are considered to be causes of cancer in human, mainly hepatitis B and C viruses, high-risk human pailloma viruses, Helicobacter pylori, Clonorchis sinensis, and Opisthorchis viverrini. Here we described the evident research and the association between Helicobacter spp. and biliary tract cancer particularly cholangiocarcinoma (CCA). Global epidemiological studies have suggested that Helicobacter spp. are possible risk factors for biliary tract diseases. Molecular studies support a linkage of Helicobacter spp...
2016: Asian Pacific Journal of Cancer Prevention: APJCP
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