Helicobacter hepaticus

Changes in the spatial organization, or biogeography, of colonic microbes have been observed in human inflammatory bowel disease (IBD) and mouse models of IBD. We have developed a mouse model of IBD that occurs spontaneously and consistently in the absence of adaptive immunity. Mice expressing tumor necrosis factor-induced protein 3 (TNFAIP3) in intestinal epithelial cells (villin-TNFAIP3) develop colitis when interbred with Recombination Activating 1-deficient mice (RAG1-/- ). The colitis in villin-TNFAIP3 × RAG1-/- (TRAG) mice is prevented by antibiotics, indicating a role for microbes in this innate colitis...

Susceptibility to Clostridioides difficile infection (CDI) typically follows the administration of antibiotics. Patients with inflammatory bowel disease (IBD) have increased incidence of CDI, even in the absence of antibiotic treatment. However, the mechanisms underlying this susceptibility are not well understood. To explore the intersection between CDI and IBD, we recently described a mouse model where colitis triggered by the murine gut bacterium, Helicobacter hepaticus, in IL-10-/- mice led to susceptibility to C...

Molecular-based methods have shown potential for improving pathogen detection and reducing animal use. While increasing evidence supports rodent-free environmental health PCR pathogen detection, limited information is available regarding efficacy for disposable individually ventilated caging systems. In such systems, testing of plenum exhaust air dust is ineffective, and the use of collection media is optimal. We performed a series of studies to compare PCR infectious agent detection with dust collected on media placed in a mouse-free soiled bedding cage, the cage exhaust filter of an occupied sentinel cage, and direct sampling from colony and sentinel mice with traditional soiled bedding mouse sentinels...

Objective: IL-17 is a key regulator of the inflammatory response, and as such, it is involved in the constraint and clearance of pathogens. The mechanism of IL-17 in the pathogenesis of inflammatory bowel disease (IBD) caused by microbial infection is still unclear. Helicobacter hepaticus infection can induce colitis in many mouse strains, and thus, it has been widely used in the study of IBD pathogenesis. Methods: In this study, male C57BL/6, BALB/c, Il-10-/- , and Il-17a-/- mice were infected with H...

Chronic inflammation of the colon causes genomic and/or transcriptomic events, which can lead to expression of non-canonical protein sequences contributing to oncogenesis. To better understand these mechanisms, Rag2 -/- Il10 -/- mice were infected with Helicobacter hepaticus to induce chronic inflammation of the cecum and the colon. Transcriptomic data from harvested proximal colon samples were used to generate a customized FASTA database containing non-canonical protein sequences. Using a proteogenomic approach, mass spectrometry data for proximal colon proteins were searched against this custom FASTA database using the Galaxy for Proteomics (Galaxy-P) platform...

Microbial dysbiosis plays an important role in the development of intestinal diseases. Recent studies suggest a link between intestinal bacteria and mammary cancer. Here, we report that female ApcMin/+ mice infected with Helicobacter hepaticus exhibited an increased mammary and small/large intestine tumor burden compared with uninfected littermates. H. hepaticus DNA was detected in small/large intestine, mammary tumors, and adjacent lymph nodes, suggesting a migration pathway. CD11b+ Gr1+ myeloid-derived suppressor cells (MDSCs) infiltrated and expressed high levels of Wnts, likely enhancing tumorigenesis through activation of Wnt/β-catenin pathway...

BACKGROUND: Murine Helicobacter species have gained increasing awareness in mouse facilities over the last years. Infections with Helicobacter species may have an impact effect on the health of mice and might pose a zoonotic risk to researchers. To minimize the interference with experiments and hence contribute to the 3Rs, a reliable method of monitoring Helicobacter infections in animal facilities needs to be available. The aim of this study was to improve and validate the detection of the most common murine Helicobacter species...

Background: The relationship between Helicobacter pylori ( H. pylori ) and hepatocellular carcinoma (HCC) was firstly proposed in 1994 after Ward et al demonstrated the role of Helicobacter hepaticus in the development of HCC in mice. Studies also investigated the role of hepatitis B virus (HBV) and hepatitis C virus (HCV) coexisting with H. pylori in causing HCC. A causal relationship was never confirmed, and the relationship remains controversial. This meta-analysis aimed to summarize the research on this topic and investigate if a relationship exists between H...

BACKGROUND: Helicobacter pylori infection is a well-established risk factor for gastric cancer and has been linked to other gastrointestinal diseases, including pancreatic and biliary tract cancers; however, the relevance of enterohepatic non-H. pylori helicobacters to the pathophysiology of these diseases remains unclear. MATERIALS AND METHODS: We estimated the prevalence of two enterohepatic non-H. pylori helicobacters (Helicobacter hepaticus and Helicobacter bilis) in the framework of a hospital-based case-control study involving 121 patients with biliary tract cancer, pancreatic cancer, or other gastrointestinal diseases...

The microbiome has a profound influence on the development and progression of cancer, as well as the response to immunotherapy. In this issue of Immunity, Overacre-Delgoffe et al. (2021) examine the impact of the immunogenic bacteria Helicobacter hepaticus (Hhep) in the immune response to colorectal cancer, providing evidence that T follicular helper (Tfh) cells that specifically recognize Hhep antigens are necessary for the control of tumor growth.

Intestinal Helicobacter hepaticus ( Hhep ) colonization promoted antitumor immunity in colon cancer.

Pathobionts are members of the gut microbiota with the capacity to cause disease when there is malfunctioning intestinal homeostasis. These organisms are thought to be major contributors to the pathogenesis of inflammatory bowel disease (IBD), a group of chronic inflammatory disorders driven by dysregulated responses towards the microbiota. Over two decades have passed since the discovery of Helicobacter hepaticus, a mouse pathobiont which causes colitis in the context of immune deficiency. During this time, we have developed a detailed understanding of the cellular players and cytokine networks which drive H...

The composition of the intestinal microbiota is associated with both the development of tumors and the efficacy of anti-tumor immunity. Here, we examined the impact of microbiota-specific T cells in anti-colorectal cancer (CRC) immunity. Introduction of Helicobacter hepaticus (Hhep) in a mouse model of CRC did not alter the microbial landscape but increased tumor infiltration by cytotoxic lymphocytes and inhibited tumor growth. Anti-tumor immunity was independent of CD8+ T cells but dependent upon CD4+ T cells, B cells, and natural killer (NK) cells...

Alzheimer's disease (AD), a neurodegenerative disease, is the leading cause of dementia. Sesamol is a lignan extracted from sesame oil and has been found to exert neuroprotective effects. The present study aimed to investigate the neuroprotective effects of sesamol on APPswe/PS1dE9 transgenic AD mice. The AD mice were fed with a diet supplemented with sesamol (0.075 w/w %). Sesamol treatment improved spatial memory and learning ability in AD mice, improved neuronal damage, and decreased Aβ accumulation. Sesamol protected the synaptic ultrastructure and inhibited neuroinflammatory responses in the brain of AD mice...

Pathogens can affect physiological and immunological reactions in immunocompromised animals and genetically engineered mice. Specifically, murine norovirus (MNV), Helicobacter, and intestinal protozoa are prevalent in rodent laboratory facilities worldwide. In this study, microbiological test results of the soiled bedding of sentinel mice showed the prevalence of MNV (50.9%, 28/55), Helicobacter hepaticus (29.1%, 16/55), Trichomonas spp. (14.5%, 8/55), and Entamoeba spp. (32.7%, 18/55). No single infections were detected as all cases were confirmed to have complex infections with two or four pathogens...

BACKGROUND & AIMS: The ligand-activated transcription factor, aryl hydrocarbon receptor (AHR) can sense xenobiotics, dietary, microbial, and metabolic cues. Roles of Ahr in intestinal epithelial cells (IECs) have been much less elucidated compared with those in intestinal innate immune cells. Here, we explored whether the IEC intrinsic Ahr could modulate the development of alcohol-related liver disease (ALD) via the gut-liver axis. METHODS: Mice with IEC specific Ahr deficiency (AhrΔIEC ) were generated and fed with a control or ethanol diet...

BACKGROUND: Health surveillance of murine colonies employed for scientific purposes aim at detecting unwanted infection that can affect the well-being of animals and personnel, and potentially undermine scientific results. In this study, we investigated the use of a next-generation sequencing (NGS) metagenomic approach for monitoring the microbiota composition and uncovering the possible presence of pathogens in mice housed in specific pathogen-free (SPF) or conventional (non-SPF) facilities...

In recent years, an increasing number of studies have reported that intestinal microbiota have an important effect on tumour immunity by affecting the tumour microenvironment (TME). The intestinal microbiota are closely associated with various immune cells, such as T lymphocytes, natural killer cells (NK cells) and macrophages. Some bacteria, such as Akkermansia muciniphila (A. muciniphila) and Lactobacillus reuteri (L. reuteri), have been shown to improve the effect of tumour immunity. Furthermore, microbial imbalance, such as the increased abundance of Fusobacterium nucleatum (F...

Sutherland et al. recently reported the in vitro inhibition of Helicobacter hepaticus cytochrome c (cyt c) synthase, which may inactivate c-type cytochromes in this and in other pathogenic bacteria. Here, I discuss the impact of this work, which identifies this conserved synthase as a potential antibacterial target.

Clostridioides difficile is a noteworthy pathogen in patients with inflammatory bowel disease (IBD). Patients with IBD who develop concurrent C. difficile infection (CDI) experience increased morbidity and mortality. IBD is associated with intestinal inflammation and alterations of the gut microbiota, both of which can diminish colonization resistance to C. difficile. Here, we describe the development of a mouse model to explore the role that IBD-induced changes of the gut microbiome play in susceptibility to C...