Immune responses to Helicobacter pylori infection

Impact of helicobacter pylori infection status on outcomes among patients with gastric cancer treated with immune checkpoint inhibitors: A systematic review and meta-analysis

BACKGROUND

Helicobacter pylori (H. pylori), a microaerophilic gram-negative bacterium, is one of the most common chronic bacterial infections in humans, affecting about 50 % of the global population. Recently, it has been proposed that H. pylori infection might impact the efficacy of immune checkpoint inhibitors (ICIs), which are used in the treatment of various cancers, including gastric cancer (GC). However, the impact of H. pylori infection on clinical outcomes in patients with GC treated with ICIs is not yet fully elucidated.

OBJECTIVES

Evaluating the impact of H. pylori infection status on overall survival (OS) and progression-free survival (PFS) on GC treated with ICIs.

METHODS

A meticulous literature search was conducted across PubMed, EMBASE, and Web of Science databases, focusing on studies that compared the effect of H. pylori-positive status versus H. pylori-negative status on patients with GC undergoing ICI treatment. The Newcastle-Ottawa Scale was utilized for the risk of bias assessment of individual studies. For binary outcomes, we used hazard ratios (HRs) or odds ratios (OR) with 95 % confidence intervals (CI) to estimate the effect size.

RESULTS

In total, 3 studies were included, involving 928 patients, of which 396 had H. pylori-positive status. Analysis showed that: PFS was prolonged but not statistically significant in H. pylori-negative patients (HR: 1.11; 95 % CI:0.94-1.31; p = 0.17), OS was significantly prolonged in H. pylori-negative patients (HR: 1.25; 95 % CI: 1.05-1.50; p=0.012), and the H. pylori-negative group had a significant clinical response compared with the H. pylori-positive group (OR: 0.40; 95 % CI: 0.28-0.57; p < 0.000001).

CONCLUSION

In this systematic review and meta-analysis, the status of H. pylori provides a perspective to reshape ICI treatment paradigms and advocates for early eradication treatment of this bacterium.

The urease E subunit vaccine stimulate the immune response versus Helicobacter pylori in animal model

There is a strong association between Helicobacter pylori (H. pylori) and the occurrence of gastritis and gastric mucosal lymphoma in the human population. Vaccination is a viable preventive measure in light of the escalating issue of antibiotic resistance. The use of DNA vaccines presents a potentially effective approach. This study used the utilization of antigenic H. pylori urease E subunit (UreE) for the development of a DNA vaccine. The UreE gene was chemically cloned into pIRES2-DsRed-Express (pDNA), and PCR and restriction enzyme digestion verified the cloning. The immunogenicity and immune-protective efficacy of the vaccination were assessed in BALB/c mice. In contrast, blood samples from BALB/c mice inoculated with pDNA-UreE showed higher levels of IgG, IFN-γ, IL- 4, and IL- 17. Furthermore, stomach damage and bacterial loads were reduced, and BALB/c mice inoculated with pDNA-UreE exhibited a significant protection rate (87.5%) against the H. pylori challenge. pDNA-UreE generated a combination of Th1-Th2-Th17 immune responses, perhaps contributing to adequate protection. Based on our findings, using this DNA immunization as a preventive measure against H. pylori infection is a viable approach.

Helicobacter pylori infection is associated with significant elevations to fecal calprotectin, systemic inflammatory markers

OBJECTIVES

Fecal calprotectin (FC) is a marker commonly used in the diagnosis and follow-up of inflammatory bowel diseases (IBD). However, other gastrointestinal conditions, like H. pylori (HP) infection, can result in increased neutrophil activity as well. We set out to assess the impact of HP infection on FC and downstream gastrointestinal care via a retrospective study.

METHODS

In this study, we collected data from two institutions in Brooklyn, NY, in a high immigrant density community. We reviewed data from patients who underwent esophagogastroduodenoscopy (EGD) between January 2017 and October 2022. Patients aged 6-18 years old with an FC level 6 months prior to EGD and HP testing were included.

RESULTS

Of 129 patients, 37 (28.7%) tested positive for HP infection. The mean FC level was significantly elevated in HP-positive patients (241.2, confidence interval [CI]: 161.0-321.3) as compared with HP-negative patients (88.1, CI: 59.1-117.0) (p < 0.001). Patients with higher FC levels were also more likely to undergo colonoscopies (p = 0.003).

DISCUSSION

HP infection is associated with increased calprotectin, and calprotectin increases in HP patients are associated with an increased risk of colonoscopy.

Effect of Helicobacter Pylori infection on immunotherapy for gastrointestinal cancer: a narrative review

Immunotherapy for gastrointestinal cancers has elicited considerable amount of attention as a viable therapeutic option for several cancer types. Gut microbiome as a whole plays a critical role in shaping immune responses and influencing cancer progression. Recent evidence suggests that Helicobacter pylori (H. pylori), may influence immunotherapy efficacy by modulating the tumor microenvironment. Infection with H. pylori is common as it affects approximately 50% of the global population and remains the leading risk factor for gastric cancer. Interestingly, recent clinical and preclinical data has associated H. pylori with colorectal cancer carcinogenesis. Gut microbiome appears to be a modulator of the relationship between the immune system, gastrointestinal cancer development and existing therapies. Infection with H. pylori may affect immunotherapy results in both gastroesophageal and colorectal cancer; favorable results were noticed in H. pylori positive patients with gastric cancer, while in colorectal cancer patients the pathogen seemed to impede immunotherapy's action. This article aims to review current data on the role of H. pylori in triggering gastric inflammation and cancer, as well as its potential involvement in colorectal cancer development. Additionally, it seeks to highlight the impact of H. pylori infection on the response to immunotherapy in gastrointestinal cancers.

Mucosal immune response in biology, disease prevention and treatment

The mucosal immune system, as the most extensive peripheral immune network, serves as the frontline defense against a myriad of microbial and dietary antigens. It is crucial in preventing pathogen invasion and establishing immune tolerance. A comprehensive understanding of mucosal immunity is essential for developing treatments that can effectively target diseases at their entry points, thereby minimizing the overall impact on the body. Despite its importance, our knowledge of mucosal immunity remains incomplete, necessitating further research. The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has underscored the critical role of mucosal immunity in disease prevention and treatment. This systematic review focuses on the dynamic interactions between mucosa-associated lymphoid structures and related diseases. We delve into the basic structures and functions of these lymphoid tissues during disease processes and explore the intricate regulatory networks and mechanisms involved. Additionally, we summarize novel therapies and clinical research advances in the prevention of mucosal immunity-related diseases. The review also addresses the challenges in developing mucosal vaccines, which aim to induce specific immune responses while maintaining tolerance to non-pathogenic microbes. Innovative therapies, such as nanoparticle vaccines and inhalable antibodies, show promise in enhancing mucosal immunity and offer potential for improved disease prevention and treatment.

Antibodies directed against bacterial antigens in sera of Polish patients with primary biliary cholangitis

Background

Primary biliary cholangitis (PBC) is a cholestatic, autoimmune liver disease with the presence of characteristic autoantibodies. The aim of the work was to determine the level of antibodies directed against bacterial antigens: Chlamydia pneumoniae (anti-Cpn), Yersinia enterolitica (anti-Y.e), Helicobacter pylori (anti-Hp), Mycoplasma pneumoniae (anti- Mp.) and Escherichia coli (E.coli) in sera of PBC patients. We also performed in vitro studies on the impact of the bacterial peptides on the specific antigen-antibody binding.

Method

We screened 92 Polish PBC patients and sera samples from healthy donors and pathological controls. Autoantibodies and anti-bacterial antibodies were determined by commercially available ELISA kits. Specific inhibition of antibody binding was also detected by the in house ELISA method.

Results

Anti-Cpn, anti-Y. enterolitica, anti-Hp, anti-M. pneumoniae and anti-E. coli antibodies were significantly more common in the group of PBC patients than in the pathological and healthy control groups: 74%, 40%, 84%, 39% and 69% respectively. The mean level of anti-Cpn, anti- Y.e, anti-Hp and anti- M.p in the PBC group was significantly higher than those in the healthy group (p < 0.001). and in patients with other liver diseases. In sera of patients with the presence of positive anti-mitochondrial antibodies (AMA), specific for PBC, anti-bacterial antibodies have been found in 80% vs. 50% in sera with AMA negative. We observed inhibition of specific antigen-antibody binding by the bacterial peptide: EClpP (E. coli caseinolytic protease) and adenine glycosylase from E. coli caseinolytic protease P, ClpP Y.e from peptide of Y. enterolitica, Mp PDC from M. pneumonia peptide and adenine glycosylase of E. coli. Bacterial factors influence the specific binding of antibodies to pyruvate dehydrogenase (PDC-E2), gp210 and KLHL12 (kelch-like peptide 12) antigens.

Conclusion

Microbial mimics may be the major targets of cross-reactivity with human pyruvate dehydrogenase, gp210, and KLHL12 in PBC.

Age-Stratified Prevalence of Helicobacter pylori Infection in Children With Recurrent Abdominal Pain: A Prospective Observational Study

Background Recurrent abdominal pain (RAP), often considered functional, is a frequent complaint among pediatric patients. However, the increasing availability of advanced diagnostic tools like upper and lower gastrointestinal endoscopy, tests for Helicobacter pylori, and abdominal ultrasound have highlighted many organic causes, including Helicobacter pylori (H. pylori) infection, whose prevalence in children remains unclear. Objectives To determine the age-stratified prevalence of H. pylori infection and investigate its role along with other etiologies contributing to RAP in pediatric patients. Methods This cross-sectional observational study was conducted between October 2019 and April 2021, involving 60 children aged two to 14 years who met the Rome IV criteria for RAP. Comprehensive evaluations included detailed history-taking, physical examination, and upper gastrointestinal endoscopy with biopsy. Mucosal samples from the antrum were subjected to a rapid urease test (RUT) to detect H. pylori infection. The presence of endoscopic abnormalities and their association with positive RUT results were analyzed to identify the underlying causes of RAP. Results H. pylori infection was identified in 11 (18.3%) children, with the highest prevalence among children aged seven to 12 years (n=34; 56.7%). All biopsy-positive cases showed concordant rapid urease test results (p=0.001). Organic etiologies were identified in 34 (56.7%) patients, with gastritis and gastric ulcers being the most common findings. Other causes included mesenteric lymphadenitis, urinary tract infections, duodenal ulcers, and hiatus hernia. Children with H. pylori infections predominantly exhibited endoscopic abnormalities, underscoring its role in RAP. Conclusion H. pylori infection shows a marked increase with age and is a significant organic cause of RAP. Thorough investigations, including endoscopic evaluations, are essential to uncover organic etiologies. Targeted treatment for H. pylori should be prioritized in children over seven years presenting with RAP, emphasizing the need for a systematic approach to diagnosing and managing this condition.

The comprehensive analysis of gut microbiome and spleen transcriptome revealed the immunomodulatory mechanism of Dendrobium officinale leaf polysaccharide on immunosuppressed mice

In recent years, the immunomodulatory efficacy of Dendrobium officinale leaf polysaccharide (DOLP) has attracted much attention, but its potential immunomodulatory mechanism remains unclear. Therefore, we investigated the molecular mechanism of DOLP to ameliorate cyclophosphamide-induced immunosuppressed mice based on transcriptome profiling technology. The results indicated that DOLP significantly mitigated damage to immune organs, regulated the expression levels of inflammatory factors and immunoglobulins, and restored the balance of gut microbiota. Furthermore, it modulated metabolic pathways associated with the immune system, including antigen processing and presentation, hematopoietic cell line development, and natural killer cell-mediated cytotoxicity. DOLP might promote host hematopoietic function to enhance immune cell proliferation and differentiation by up-regulating Cd19, Cr2 and Il7r but down-regulating Dntt. DOLP also up-regulated the expression of MHC-1 (Gm11127, H2-K1, H2-Q10, H2-Q6, and H2-Q7), thus promoting antigen recognition by NK cells to enhance the innate immunity and helping T cells to deliver antigen and secrete immune factors so that enhancing the adaptive immunity.

The role of Helicobacter pylori in the development of inflammatory eyelid diseases

Background. Blepharitis is one of the most common eye diseases: it accounts for 23.3 % of the total number of patients with inflammatory eye diseases worldwide. 40.2 % of these patients seek outpatient care. The incidence of blepharitis is 1.5–2 times higher in women than in men. The leading factors in the development of blepharitis are both general (gastrointestinal tract diseases, diabetes mellitus, hypertension, systemic use of corticosteroids, etc.) and local (atopic and seborrheic dermatitis or rosacea). The main causative agents of this disease are Staphylococcus spp. (S. aureus, S. epidermidis). As a rule, the disease manifests itself in patients aged 30–50 years, while in women aged 40 to 45 years, 80 % of blepharitis are of staphylococcal origin. Currently, there are reports in the literature about apotential link between Helicobacter pylori infection and the development of chronic blepharitis, but the data are very contradictory.

The aim of the study. To analyze the features of the relationship between Helicobacter pylori and inflammatory eyelid diseases.

Materials and methods. We conducted a search and analysis of literary sources in the Web of Science, PubMed and Google Scholar databases, as well as in the Russian Science Citation Index database for the period from 2000 to 2022.

Conclusion. The review analyzes and summarizes the pathogenic mechanisms of the relationship between chronic blepharitis and Helicobacter pylori. We carried out an analysis of numerous studies, which give grounds to assume a possible role of Helicobacter pylori infection in the development and course of inflammatory eyelid diseases (blepharitis). The main pathogenic aspects in these studies are: chronic inflammation of the eyelids and gastrointestinal tract (antigenic mimicry); excretion of toxic substances from the oral cavity (ammonia, hydrogen nitrite, hydrogen cyanide and other substances causing indirect inflammation of the conjunctiva and eyelid cartilage); the presence of Helicobacter pylori in tears.

Insights into the molecular mechanisms of H. pylori-associated B-cell lymphoma

Cancer research has extensively explored various factors contributing to cancer development, including chemicals, drugs, smoking, and obesity. However, the role of bacterial infections in cancer induction remains underexplored. In particular, the mechanisms underlying H. pylori-induced B-cell lymphoma, a potential consequence of bacterial infection, have received little attention. In recent years, there has been speculation about contagious agents causing persistent inflammation and encouraging B-lymphocyte transition along with lymphomagenesis. MALT lymphoma associated with chronic H. pylori infection, apart from two other central associated lymphomas - Burkitt's Lymphoma and DLBCL, is well studied. Owing to the increasing colonization of H. pylori in the host gut and its possible action in the development of B-cell lymphoma, this review aims to summarize the existing reports on different B-cell lymphomas' probable association with H. pylori infections; also emphasizing the function of the organism in lymphomagenesis; including its interaction with the host, pathogen and host-specific factors, and tumor microenvironment.

Role of the Microbiome in the Diagnosis and Management of Gastroesophageal Cancers

PURPOSE

Stomach and esophageal cancers are among the highest mortality from cancers worldwide. Microbiota has an interplaying role within the human gastrointestinal (GI) tract. Dysbiosis occurs when a disruption of the balance between the microbiota and the host happens. With this narrative review, we discuss the main alterations in the microbiome of gastroesophageal cancer, revealing its potential role in the pathogenesis, early detection, and treatment.

RESULTS

Helicobacter pylori plays a major role the development of a cascade of preneoplastic conditions ranging from atrophic gastritis to metaplasia and dysplasia, ultimately culminating in gastric cancer, while other pathogenic agents are Fusobacterium nucleatum, Bacteroides fragilis, Escherichia coli, and Lactobacillus. Campylobacter species (spp.)'s role in the progression of esophageal adenocarcinoma may parallel that of Helicobacter pylori in the context of gastric cancer, with other esophageal carcinogenic agents being Escherichia coli, Bacteroides fragilis, and Fusobacterium nucleatum. Moreover, gut microbiome could significantly alter the outcomes of chemotherapy and immunotherapy. The gut microbiome can be modulated through interventions such as antibiotics, probiotics, or prebiotics intake. Fecal microbiota transplantation has emerged as a therapeutic strategy as well.

CONCLUSIONS

Nowadays, it is widely accepted that changes in the normal gut microbiome causing dysbiosis and immune dysregulation play a role gastroesophageal cancer. Different interventions, including probiotics and prebiotics intake are being developed to improve therapeutic outcomes and mitigate toxicities associated with anticancer treatment. Further studies are required in order to introduce the microbiome among the available tools of precision medicine in the field of anticancer treatment.

Critical role of the gut microbiota in immune responses and cancer immunotherapy

The gut microbiota plays a critical role in the progression of human diseases, especially cancer. In recent decades, there has been accumulating evidence of the connections between the gut microbiota and cancer immunotherapy. Therefore, understanding the functional role of the gut microbiota in regulating immune responses to cancer immunotherapy is crucial for developing precision medicine. In this review, we extract insights from state-of-the-art research to decipher the complicated crosstalk among the gut microbiota, the systemic immune system, and immunotherapy in the context of cancer. Additionally, as the gut microbiota can account for immune-related adverse events, we discuss potential interventions to minimize these adverse effects and discuss the clinical application of five microbiota-targeted strategies that precisely increase the efficacy of cancer immunotherapy. Finally, as the gut microbiota holds promising potential as a target for precision cancer immunotherapeutics, we summarize current challenges and provide a general outlook on future directions in this field.

Helicobacter pylori-Toxoplasma gondii interplay with a possible role of IL-10

Parasites are known for their modulatory effects on the immune response. The impact of toxoplasmosis on the immune response towards H. pylori is being studied in terms of IL-10 levels. This study included 110 patients suffering from persistent dyspepsia and 50 apparently healthy controls. Stool samples were collected and tested for H. pylori using colloidal gold one step test. Sera were examined for anti-Toxoplasma IgM and IgG using ELISA. IL-10 was also tested in the sera using ELISA. We found that Toxoplasma IgM and IgG tested positive in 1.8 % and 40 % of H. pylori positive patients, respectively. H. pylori-infected patients displayed higher IL-10 levels than the healthy controls (84 versus 0.59 pg/ml, respectively, P < 0.001). Classification of H. pylori positive patients according to Toxoplasma IgG titers yielded three groups: negative (58, 52.7 %), equivocal (8, 7.3 %), and positive (44, 40 %) groups, with the highest IL-10 levels detected in the double positive than the negative and the equivocal group (215 pg/ml versus 43 and 112.5 pg/ml, respectively, P < 0.001). There was strong positive correlation between Toxoplasma IgG titers and IL-10 levels (rs = 0.82, P < 0.001). Toxoplasma enhances IL-10 production in response to H. pylori infection. This could ameliorate the inflammatory response in the gastric mucosa, and subsequently more colonization with the H. pylori is achieved, resulting in persistent infection.

CCR6+ T helper cells and regulatory T cells in the blood and gastric mucosa during Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H. pylori) can evade the host's immune response and persist for a long time on the gastric mucosa. T helper (Th) cells appear to be involved in the control of H. pylori bacteria but promote mucosal inflammation. In contrast, regulatory T cells (Tregs) may reduce inflammation but promote H. pylori persistence. CC motif chemokine receptor 6 (CCR6) is involved in the migration of various cells into inflamed gastric mucosa. In this study, we examined CCR6+ Th cells and CCR6+ Tregs during H. pylori infection in humans.

MATERIALS AND METHODS

Isolation of cells from blood and mucosal biopsies, magnetic separation of В cells, CD4+ and CD4+CCR6+CD45RO+ T cells, antigen-specific activation, B cell response in vitro, flow cytometry, determination of CD4+CD25hiFoxP3+ Tregs and various groups of Th cells.

RESULTS

CD4+CCR6+ blood lymphocytes from healthy donors included Th cells and Tregs. These CCR6+ Th cells produced proinflammatory cytokines and also stimulated plasma cell maturation and antibody production in vitro. H. pylori gastritis and peptic ulcer disease were associated with an increase in the number of circulate CD4+CCR6+CD45RO+ cells and the percentage of Th1, Th17 and Th1/17 cells in this lymphocyte subgroup. In H. pylori-positive patients, circulating CD4+CCR6+ cells contained a higher proportion of H. pylori-specific cells compared with their CD4+CCR6- counterparts. H. pylori infection strongly increased the content of CD4+ lymphocytes in the inflamed gastric mucosa, with the majority of these CD4+ lymphocytes expressing CCR6. CD4+CCR6+ lymphocytes from H. pylori-infected stomach included Tregs and in vivo activated T cells, some of which produced interferon-γ without ex vivo stimulation.

CONCLUSION

H. pylori infection causes an increase in the number of mature CD4+CCR6+ lymphocytes in the blood, with a pro-inflammatory shift in their composition and enrichment of the gastric mucosa with CD4+CCR6+ lymphocytes, including CCR6+ Th1 cells and Tregs.

Immunoinformatics-Based Designing of Novel and Potent Multi-Epitope PSA D15 and Cag11 Immunogens for Helicobacter pylori Immunodiagnostic Assay Development

Helicobacter pylori (H. pylori) strain is the most genetically diverse pathogenic bacterium and now alarming serious human health concern ranging from chronic gastritis to gastric cancer and human death all over the world. Currently, the majority of commercially available diagnostic assays for H. pylori is a challenging task due to the heterogeneity of virulence factors in various geographical regions. In this concern, designing of universal multi-epitope immunogenic biomarker targeted for all H. pylori strains would be crucial to successfully immunodiagnosis assay and vaccine development for H. pylori infection. Hence, the present study aimed to explore the potential immunogenic epitopes of PSA D15 and Cag11 proteins of H. pylori, using immunoinformatics web tools in order to design novel immune-reactive multi-epitope antigens for enhanced immunodiagnosis in humans. Through an in silico immunoinformatics approach, high-ranked B-cell, MHC-I, and MHC-II epitopes of PSA D15 and Cag11 proteins were predicted, screened, and selected. Subsequently, a novel multi-epitope PSA D15 and Cag11 antigens were designed by fused the high-ranked B-cell, MHC-I, and MHC-II epitopes and 50S ribosomal protein L7/L12 adjuvant using linkers. The antigenicity, solubility, physicochemical properties, secondary and tertiary structures, 3D model refinement, and validations were carried. Furthermore, the designed multi-epitope antigens were subjected to codon adaptation and in silico cloning, immune response simulation, and molecular docking with receptor molecules. A novel, stable multi-epitope PSA D15 and Cag11 H. pylori antigens were developed and immune simulation of the designed antigens showed desirable levels of immunological response. Molecular docking of designed antigens with immune receptors (B-cell, MHC-I, MHC-II, and TLR-2/4) revealed robust interactions and stable binding affinity to the receptors. The codon optimized and in silico cloned showed that the designed antigens were successfully expressed (CAI value of 0.95 for PSA D15 and 1.0 for Cag11) after inserted into pET-32ba (+) plasmid of the E. coli K12 strain. In conclusion, this study revealed that the designed multi-epitope antigens have a huge immunological potential candidate biomarker and useful in developing immunodiagnostic assays and vaccines for H. pylori infection.

Differential cytokine expression in gastric tissues highlights helicobacter pylori's role in gastritis

Helicobacter pylori (H. pylori), known for causing gastric inflammation, gastritis and gastric cancer, prompted our study to investigate the differential expression of cytokines in gastric tissues, which is crucial for understanding H. pylori infection and its potential progression to gastric cancer. Focusing on Il-1β, IL-6, IL-8, IL-12, IL-18, and TNF-α, we analysed gene and protein levels to differentiate between H. pylori-infected and non-infected gastritis. We utilised real-time quantitative polymerase chain reaction (RT-qPCR) for gene quantification, immunohistochemical staining, and ELISA for protein measurement. Gastric samples from patients with gastritis were divided into three groups: (1) non-gastritis (N-group) group, (2) gastritis without H. pylori infection (G-group), and (3) gastritis with H. pylori infection (GH-group), each consisting of 8 samples. Our findings revealed a statistically significant variation in cytokine expression. Generally, cytokine levels were higher in gastritis, but in H. pylori-infected gastritis, IL-1β, IL-6, and IL-8 levels were lower compared to H. pylori-independent gastritis, while IL-12, IL-18, and TNF-α levels were higher. This distinct cytokine expression pattern in H. pylori-infected gastritis underscores a unique inflammatory response, providing deeper insights into its pathogenesis.

Acute Helicobacter pylori infection prevalence and association with metabolic abnormality in general Chinese population: A retrospective study

Helicobacter pylori (H pylori) infection was common worldwide and previous researches on the correlation between H pylori infection and metabolic abnormality provided inconsistent conclusions. We assessed acute H pylori infection prevalence and the relationship with metabolic abnormality in general Chinese population. Participants attending for the physical examination underwent a carbon-13 urea breath test. For individual, the following data were collected: age, gender, body mass index (BMI), systolic blood pressure, diastolic blood pressure, total protein, albumin, globulin (GLB), total bilirubin, direct bilirubin (DBIL), indirect bilirubin, alanine transaminase, glutamyl transpeptidase, alkaline phosphatase, cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, urea nitrogen, creatinine, uric acid, fasting plasma glucose (FPG), and homocysteine. A total of 29,154 participants were enrolled. The prevalence of acute H pylori infection was 29.79% (8684/29,154). Spearson correlation analysis showed that gender, BMI, ALB, GLB, total bilirubin, DBIL, indirect bilirubin, and FPG were closely related to H pylori infection. Multinomial logistic regressions analysis with stepwise subset selection further identified gender, BMI, ALB, GLB, DBIL, and FPG as independent risk factors for acute H pylori infection. Our results indicated that acute H pylori infection might has a significant impact on metabolic abnormalities, which should be further confirmed.

Increased infiltration of CD4+ IL-17A+ FOXP3+ T cells in Helicobacter pylori-induced gastritis

Helicobacter pylori is one of the main predisposing factors for gastric cancer, causing chronic inflammation and proper glands atrophy in the gastric mucosa. Although H. pylori-induced inflammation is a key inducer of precancerous lesions in the gastric mucosa, it remains unclear which precise immune cell subsets are responsible for the progression of H. pylori-induced gastritis. Here, we observed an abundance of CD4+ IL-17A+ FOXP3+ T cells exhibiting a Th17-like phenotype within the microenvironment of H. pylori-induced gastritis. Mechanistically, H. pylori upregulated the expression of IL-6 in Dendritic cells and macrophages, by activating NF-κB signaling through the virulence factor CagA and thus, induced IL-17A expression in FOXP3+ T cells. Moreover, CD4+ IL-17A+ FOXP3+ T cells were positively associated with advanced precancerous lesions. Therefore, these findings offer essential insights into how FOXP3+ T cells sense inflammatory signals from the environment, such as IL-6, during H. pylori infections, thereby guiding the effector immune response and aggravating the gastritis.

Helicobacter pylori and epithelial mesenchymal transition in human gastric cancers: An update of the literature

Gastric cancer, a multifactorial disease, is considered one of the most common malignancies worldwide. In addition to genetic and environmental risk factors, infectious agents, such as Epstein-Barr virus (EBV) and Helicobacter pylori (H.pylori) contribute to the onset and development of gastric cancer. H. pylori is a type I carcinogen that colonizes the gastric epithelium of approximately 50% of the world's population, thus increasing the risk of gastric cancer development. On the other hand, epithelial mesenchymal transition (EMT) is a fundamental process crucial to embryogenic growth, wound healing, organ fibrosis and cancer progression. Several studies associate gastric pathogen infection of the epithelium with EMT initiation, provoking cancer metastasis in the gastric mucosa through various molecular signaling pathways. Additionally, EMT is implicated in the progression and development of H. pylori-associated gastric cancer. In this review, we recapitulate recent findings elucidating the association between H. pylori infection in EMT promotion leading to gastric cancer progression and metastasis.

Impact of Helicobacter pylori infection on the efficacy of immune checkpoint inhibitors for cancer treatment: a meta-analysis

Aim: The present systematic review and meta-analysis was designed to assess the impact of Helicobacter pylori infection on the efficacy of immune checkpoint inhibitors (ICIs). Materials & methods: PubMed, Scopus, Web of Science and EMBASE databases were systematically searched up to 1 February 2023. Results: Three studies comprising 263 patients treated with ICIs were included. The results of pooled analysis showed that H. pylori infection was associated with reduced overall survival and progression-free survival. Furthermore, the rate of progressive disease after administration of ICIs was higher in H. pylori-positive patients relative to H. pylori-negative patients. Conclusion: H. pylori infection status is a novel potential response biomarker for predicting the efficacy of ICIs in different cancers.

Metabolic alterations in patients with Helicobacter pylori-related gastritis: The H. pylori-gut microbiota-metabolism axis in progression of the chronic inflammation in the gastric mucosa

PURPOSE

To characterize the serum metabolism in patients with Helicobacter pylori-positive and H. pylori-negative gastritis.

METHODS

Clinical data and serum gastric function parameters, PGI (pepsinogen I), PGII, PGR (PGI/II), and G-17 (gastrin-17) of 117 patients with chronic gastritis were collected, including 57 H. pylori positive and 60 H. pylori negative subjects. Twenty cases in each group were randomly selected to collect intestinal mucosa specimens and serum samples. The gut microbiota profiles were generated by 16S rRNA gene sequencing, and the serum metabolites were analyzed by a targeted metabolomics approach based on liquid chromatography-mass spectrometry (LC-MS) technology.

RESULTS

Altered expression of 20 metabolites, including isovaleric acid, was detected in patients with HPAG. Some taxa of Bacteroides, Fusobacterium, and Prevotella in the gut microbiota showed significant correlations with differentially expressed metabolites between H. pylori positive and H. pylori negative individuals. As a result, an H. pylori-gut microbiota-metabolism (HGM) axis was proposed.

CONCLUSION

Helicobacter pylori infection may influence the progression of mucosal diseases and the emergence of other complications in the host by altering the gut microbiota, and thus affecting the host serum metabolism.

Increased IL-17A Serum Levels and Gastric Th17 Cells in Helicobacter pylori-Infected Patients with Gastric Premalignant Lesions

Background: Helicobacter pylori infection is characterized by an inflammatory infiltrate that might be an important antecedent of gastric cancer. The purpose of this study was to evaluate whether interleukin (IL)-17 inflammation is elicited by gastric T cells in Helicobacter pylori patients with gastric intestinal metaplasia and dysplasia (IM/DYS). We also investigated the serum IL-17A levels in Helicobacter pylori patients with gastric intestinal metaplasia and dysplasia, and patients with Helicobacter pylori non-atrophic gastritis (NAG). Methods: the IL-17 cytokine profile of gastric T cells was investigated in six patients with IM/DYS and Helicobacter pylori infection. Serum IL-17A levels were measured in 45 Helicobacter pylori-infected IM/DYS patients, 45 Helicobacter pylori-infected patients without IM/DYS and in 45 healthy controls (HC). Results: gastric T cells from all IM/DYS patients with Helicobacter pylori were able to proliferate in response to Helicobacter pylori and to produce IL-17A. The Luminex analysis revealed that IL-17A levels were significantly increased in Helicobacter pylori IM/DYS patients compared to healthy controls and to Helicobacter pylori gastritis patients without IM/DYS (452.34 ± 369.13 pg/mL, 246.82 ± 156.06 pg/mL, 169.26 ± 73.82 pg/mL, respectively; p < 0.01, p < 0.05). Conclusions: the results obtained indicate that Helicobacter pylori is able to drive gastric IL-17 inflammation in IM/DYS Helicobacter pylori-infected patients, and that IL-17A serum levels are significantly increased in Helicobacter pylori-infected patients with IM/DYS.

Gut Microbiota in Colorectal Cancer: Biological Role and Therapeutic Opportunities

Colorectal cancer (CRC) is the second-leading cause of cancer-related deaths worldwide. While CRC is thought to be an interplay between genetic and environmental factors, several lines of evidence suggest the involvement of gut microbiota in promoting inflammation and tumor progression. Gut microbiota refer to the ~40 trillion microorganisms that inhabit the human gut. Advances in next-generation sequencing technologies and metagenomics have provided new insights into the gut microbial ecology and have helped in linking gut microbiota to CRC. Many studies carried out in humans and animal models have emphasized the role of certain gut bacteria, such as Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, and colibactin-producing Escherichia coli, in the onset and progression of CRC. Metagenomic studies have opened up new avenues for the application of gut microbiota in the diagnosis, prevention, and treatment of CRC. This review article summarizes the role of gut microbiota in CRC development and its use as a biomarker to predict the disease and its potential therapeutic applications.

Helicobacter pyloril-asparaginase: a study of immunogenicity from an in silico approach

Helicobacter pylori has become the causal agent of multiple forms of gastric disease worldwide, including gastric cancer. The enzyme l-asparaginase (ASNase) has been studied as a virulence factor. In this work, we performed an in silico investigation to characterize the immunological profile of H. pylori ASNase (HpASNase) to ascertain the possible implication of HpASNase immunogenicity in the H. pylori virulence mechanism. We applied a workflow based on bioinformatics tools, which, by calculating the relative frequency of immunogenic T-cell and B-cell epitopes, allowed us to predict the immunogenicity and allergenicity of HpASNase in silico. We also visualized the epitopes by mapping them into the native structure of the enzyme. We report for the first time the T-cell and B-cell epitope composition that contributes to the immunogenicity of this HpASNase, as well as the regions that could generate a hypersensitivity response in humans. ASNase from H. pylori resulted in highly immunogenic and allergenic. The high immunogenicity of HpASNase could imply the pathogenic mechanisms of H. pylori. This knowledge could be important for the development of new drugs against H. pylori infections.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03359-0.

Helicobacter trogontum Bacteremia and Lower Limb Skin Lesion in a Patient with X-Linked Agammaglobulinemia-A Case Report and Review of the Literature

We describe the first case of infection with Helicobacter trogontum in a patient with X-linked agammaglobulinemia. A 22-year-old male with X-linked agammaglobulinemia presented with fever, malaise and a painful skin lesion on the lower left extremity. Spiral shaped Gram-negative rods were isolated from blood cultures and later identified as Helicobacter trogontum. The patient was treated with various intravenous and oral antibiotic regimens over a period of 10 months, each causing seemingly full clinical and paraclinical remission, yet several episodes of relapse occurred after cessation of antibiotic treatment. The review of the literature showed that only a few cases of infections with enterohepatic helicobacters belonging to the Flexispira rappini taxons have previously been reported. The majority of cases included patients with X-linked agammaglobulinemia and the symptomatology and course of disease were similar to the case described here. Infections with enterohepatic helicobacters, including Helicobacter trogontum, should be considered in patients with X-linked agammaglobulinemia presenting with fever, malaise and skin lesions. Careful cultivation and microbiological investigation are essential to determine the diagnosis and a long treatment period of over 6 months must be expected for successful eradication.

Helicobacter pylori serology is associated with worse overall survival in patients with melanoma treated with immune checkpoint inhibitors

The microbiome is now regarded as one of the hallmarks of cancer and several strategies to modify the gut microbiota to improve immune checkpoint inhibitor (ICI) activity are being evaluated in clinical trials. Preliminary data regarding the upper gastro-intestinal microbiota indicated that Helicobacter pylori seropositivity was associated with a negative prognosis in patients amenable to ICI. In 97 patients with advanced melanoma treated with ICI, we assessed the impact of H. pylori on outcomes and microbiome composition. We performed H. pylori serology and profiled the fecal microbiome with metagenomics sequencing. Among the 97 patients, 22% were H. pylori positive (Pos). H. pylori Pos patients had a significantly shorter overall survival (p = .02) compared to H. pylori negative (Neg) patients. In addition, objective response rate and progression-free survival were decreased in H. pylori Pos patients. Metagenomics sequencing did not reveal any difference in diversity indexes between the H. pylori groups. At the taxa level, Eubacterium ventriosum, Mediterraneibacter (Ruminococcus) torques, and Dorea formicigenerans were increased in the H. pylori Pos group, while Alistipes finegoldii, Hungatella hathewayi and Blautia producta were over-represented in the H. pylori Neg group. In a second independent cohort of patients with NSCLC, diversity indexes were similar in both groups and Bacteroides xylanisolvens was increased in H. pylori Neg patients. Our results demonstrated that the negative impact of H. pylori on outcomes seem to be independent from the fecal microbiome composition. These findings warrant further validation and development of therapeutic strategies to eradicate H. pylori in immuno-oncology arena.

The Efficacy of Cancer Immunotherapies Is Compromised by Helicobacter pylori Infection

Helicobacter pylori infects the gastric mucosa of a large number of humans. Although asymptomatic in the vast majority of cases, H pylori infection can lead to the development of peptic ulcers gastric adenocarcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma. Using a variety of mechanisms, H pylori locally suppresses the function of the host immune system to establish chronic infection. Systemic immunomodulation has been observed in both clinical and pre-clinical studies, which have demonstrated that H pylori infection is associated with reduced incidence of inflammatory diseases, such as asthma and Crohn’s disease. The introduction of immunotherapies in the arsenal of anti-cancer drugs has revealed a new facet of H pylori-induced immune suppression. In this review, we will describe the intimate interactions between H pylori and its host, and formulate hypothtyeses describing the detrimental impact of H pylori infection on the efficacy of cancer immunotherapies.

Helicobacter pylori and the Role of Lipopolysaccharide Variation in Innate Immune Evasion

Helicobacter pylori is an important human pathogen that infects half the human population and can lead to significant clinical outcomes such as acute and chronic gastritis, duodenal ulcer, and gastric adenocarcinoma. To establish infection, H. pylori employs several mechanisms to overcome the innate and adaptive immune systems. H. pylori can modulate interleukin (IL) secretion and innate immune cell function by the action of several virulence factors such as VacA, CagA and the type IV secretion system. Additionally, H. pylori can modulate local dendritic cells (DC) negatively impacting the function of these cells, reducing the secretion of immune signaling molecules, and influencing the differentiation of CD4⁺ T helper cells causing a bias to Th1 type cells. Furthermore, the lipopolysaccharide (LPS) of H. pylori displays a high degree of phase variation and contains human blood group carbohydrate determinants such as the Lewis system antigens, which are proposed to be involved in molecular mimicry of the host. Lastly, the H. pylori group of outer membrane proteins such as BabA play an important role in attachment and interaction with host Lewis and other carbohydrate antigens. This review examines the various mechanisms that H. pylori utilises to evade the innate immune system as well as discussing how the structure of the H. pylori LPS plays a role in immune evasion.

Research Progress of Biomarkers for Immune Checkpoint Inhibitors on Digestive System Cancers

Immunotherapy represented by immune checkpoint inhibitors has gradually entered a new era of precision medicine. In view of the limited clinical benefits of immunotherapy in patients with digestive system cancers, as well as the side-effects and high treatment costs, development of biomarkers to predict the efficacy of immune therapy is a key imperative. In this article, we review the available evidence of the value of microsatellite mismatch repair, tumor mutation burden, specific mutated genes or pathways, PD-L1 expression, immune-related adverse reactions, blood biomarkers, and patient-related biomarkers in predicting the efficacy of immunotherapy against digestive system cancers. Establishment of dynamic personalized prediction models based on multiple biomarkers is a promising area for future research.

Cordycepin exhibits anti-bacterial and anti-inflammatory effects against gastritis in Helicobacter pylori-infected mice

Helicobacter pylori is one of the dominant members of gastric microbiota associated with gastritis. Chronic H. pylori colonization may yield detrimental consequences, including mucosal layer atrophy, gastritis, and gastric cancer. The traditional antibiotic treatment might result in antibiotic resistance. To overcome this obstacle, this study aims to investigate the potential antibacterial and anti-inflammatory effects of cordycepin on mice infected with H. pylori. A mouse model of H. pylori infection was established. The expression levels of target genes were evaluated by qRT-PCR, western blotting, or ELISA. The infiltrated Th17 cell population was determined by flow cytometry analysis. Our results demonstrated that the administration of cordycepin exhibited up to 3-fold antibacterial effect against H. pyloriin vivo. Cordycepin treatment resulted in around 50% inflammatory cytokine production (e.g. IL-6 and IL-1β) and about 60% immune cell infiltration (e.g. Th17 cells) when compared to vehicle control group. Thus, we confirmed that cordycepin conferred antibacterial and anti-inflammatory effects on H. pylori-infected mice. Cordycepin may serve as a potential candidate for developing a therapeutic regimen for H. pylori-induced gastritis.

Helicobacter pylori infection has a detrimental impact on the efficacy of cancer immunotherapies

OBJECTIVE

In this study, we determined whether Helicobacter pylori (H. pylori) infection dampens the efficacy of cancer immunotherapies.

DESIGN

Using mouse models, we evaluated whether immune checkpoint inhibitors or vaccine-based immunotherapies are effective in reducing tumour volumes of H. pylori-infected mice. In humans, we evaluated the correlation between H. pylori seropositivity and the efficacy of the programmed cell death protein 1 (PD-1) blockade therapy in patients with non-small-cell lung cancer (NSCLC).

RESULTS

In mice engrafted with MC38 colon adenocarcinoma or B16-OVA melanoma cells, the tumour volumes of non-infected mice undergoing anticytotoxic T-lymphocyte-associated protein 4 and/or programmed death ligand 1 or anti-cancer vaccine treatments were significantly smaller than those of infected mice. We observed a decreased number and activation status of tumour-specific CD8⁺ T cells in the tumours of infected mice treated with cancer immunotherapies independent of the gut microbiome composition. Additionally, by performing an in vitro co-culture assay, we observed that dendritic cells of infected mice promote lower tumour-specific CD8⁺ T cell proliferation. We performed retrospective human clinical studies in two independent cohorts. In the Dijon cohort, H. pylori seropositivity was found to be associated with a decreased NSCLC patient survival on anti-PD-1 therapy. The survival median for H. pylori seropositive patients was 6.7 months compared with 15.4 months for seronegative patients (p=0.001). Additionally, in the Montreal cohort, H. pylori seropositivity was found to be associated with an apparent decrease of NSCLC patient progression-free survival on anti-PD-1 therapy.

CONCLUSION

Our study unveils for the first time that the stomach microbiota affects the response to cancer immunotherapies and that H. pylori serology would be a powerful tool to personalize cancer immunotherapy treatment.

Association of gastric lymphofollicular hyperplasia with Helicobacter-like organisms in dogs

Background

The relationships among gastric lymphoid follicular hyperplasia (GLFH), Helicobacter‐like organisms (HLOs), and clinical signs have not been established in dogs.

Objectives

To evaluate the epidemiologic, clinical, endoscopic, and histopathologic findings associated with GLFH in dogs, and determine the association of GLFH with HLOs and the French Bulldog (FB) breed.

Animals

Two hundred eighty‐eight dogs that underwent gastroscopy between 2013 and 2016.

Methods

Retrospective, cross‐sectional study. Gastric biopsy samples were reviewed and scored for inflammation and HLOs. Dogs were divided into 3 groups: group 1 (63 FBs), group 2 (45 non‐FB brachycephalic dogs), and group 3 (180 nonbrachycephalic dogs). Variables were evaluated for their association with GLFH.

Results

Univariate analysis determined that intact males, young age, vomiting, gastroscopic findings (discoloration, hemorrhage, and ulcers), and histopathologic findings (gastric lamina propria lymphocytic infiltration and HLO score) were associated with GLFH (P ≤ .03). In the multivariate analysis, GLFH was associated with the HLO score (odds ratio [OR] > 5 for HLO scores 1‐2 and >15 for HLO score of 3; P < .001), with vomiting (OR > 4; P = .01) but not with FB breed (P = .76) and age (P = .1). The HLO score was associated with younger age (P < .001).

Conclusion and Clinical Importance

The HLO score was associated with a high GLFH score. Vomiting was associated with GLFH. Helicobacter‐like organisms are highly prevalent in young dogs and GLFH is indirectly associated with this factor. Clinical relevance of the identification of GLFH and HLO remains to be determined.

Identification of functional tumor necrosis factor-alpha promoter variants associated with Helicobacter pylori infection in the Sudanese population: Computational approach

BACKGROUND

Helicobacter pylori (H. pylori) is a ubiquitous bacterium that affects nearly half of the world's population with a high morbidity and mortality rate. Polymorphisms within the tumor necrosis factor-alpha (TNF-A) promoter region are considered a possible genetic basis for this disease.

AIM

To functionally characterize the genetic variations in the TNF-A 5'-region (-584 to +107) of Sudanese patients infected with H. pylori using in silico tools.

METHODS

An observational study was carried out in major public and private hospitals in Khartoum state. A total of 122 gastric biopsies were taken from patients who had been referred for endoscopy. Genomic DNA was extracted. Genotyping of the TNF-A-1030 polymorphism was performed using PCR with confronting two-pair primer to investigate its association with the susceptibility to H. pylori infection in the Sudanese population. Furthermore, Sanger sequencing was applied to detect single nucleotide polymorphisms in the 5'-region (-584 to +107) of TNF-A in H. pylori-infected patients. Bioinformatics analyses were used to predict whether these mutations would alter transcription factor binding sites or composite regulatory elements in this region. A comparative profiling analysis was conducted in 11 species using the ECR browser and multiple-sequence local alignment and visualization search engine to investigate the possible conservation. Also, a multivariate logistic regression model was constructed to estimate odds ratios and their 95% confidence intervals for the association between TNF-A-1030, sociodemographic characteristics and H. pylori infection. Differences were statistically significant if P < 0.05. Statistical analyses were performed using Stata version 11 software.

RESULTS

A total of seven single nucleotide polymorphisms were observed in the TNF-A 5'-region of Sudanese patients infected with H. pylori. Only one of them (T > A, -76) was located at the in silico-predicted promoter region (-146 to +10), and it was predicted to alter transcription factor binding sites and composite regulatory elements. A novel mutation (A > T, +27) was detected in the 5' untranslated region, and it could affect the post-transcriptional regulatory pathways. Genotyping of TNF-A-1030 showed a lack of significant association between -1030T and susceptibility to H. pylori and gastric cancer in the studied population (P = 0.1756) and (P = 0.8116), respectively. However, a significant association was detected between T/C genotype and H. pylori infection (39.34% vs 19.67%, odds ratio = 2.69, 95% confidence interval: 1.17-6.17, P = 0.020). Mammalian conservation was observed for the (-146 to +10) region in chimpanzee (99.4%), rhesus monkey (95.6%), cow (91.8%), domesticated dog (89.3%), mouse (84.3%), rat (82.4%) and opossum (78%).

CONCLUSION

Computational analysis was a valuable method for understanding TNF-A gene expression patterns and guiding further in vitro and in vivo experimental validation.

Two Distinct Etiologies of Gastric Cancer: Infection and Autoimmunity

Gastric cancer is a leading cause of mortality worldwide. The risk of developing gastric adenocarcinoma, which comprises >90% of gastric cancers, is multifactorial, but most associated with Helicobacter pylori infection. Autoimmune gastritis is a chronic autoinflammatory syndrome where self-reactive immune cells are activated by gastric epithelial cell autoantigens. This cause of gastritis is more so associated with the development of neuroendocrine tumors. However, in both autoimmune and infection-induced gastritis, high risk metaplastic lesions develop within the gastric mucosa. This warrants concern for carcinogenesis in both inflammatory settings. There are many similarities and differences in disease progression between these two etiologies of chronic gastritis. Both diseases have an increased risk of gastric adenocarcinoma development, but each have their own unique comorbidities. Autoimmune gastritis is a primary cause of pernicious anemia, whereas chronic infection typically causes gastrointestinal ulceration. Both immune responses are driven by T cells, primarily CD4⁺ T cells of the IFN-γ producing, Th1 phenotype. Neutrophilic infiltrates help clear H. pylori infection, but neutrophils are not necessarily recruited in the autoimmune setting. There have also been hypotheses that infection with H. pylori initiates autoimmune gastritis, but the literature is far from definitive with evidence of infection-independent autoimmune gastric disease. Gastric cancer incidence is increasing among young women in the United States, a population at higher risk of developing autoimmune disease, and H. pylori infection rates are falling. Therefore, a better understanding of these two chronic inflammatory diseases is needed to identify their roles in initiating gastric cancer.

<i>Helicobacter pylori</i>. The survival strategy of a commensal symbiont in the <i>Homo sapiens</i> population

Несмотря на крайне высокую степень инфицированности Helicobacter pylori в популяции Homo sapiens, подавляющее большинство инфицированных являются бессимптомными носителями. Широкое распространение инфекции H. pylori среди лиц без признаков патологии и низкая заболеваемость при хронической колонизации слизистой оболочки желудка указывают на то, что H. pylori с большей вероятностью является условно-патогенным микроорганизмом или патобионтом. Популяционная ликвидация инфекции H. pylori существенно снизила заболеваемость инфекцией H. pylori, однако появление устойчивости к противомикробным препаратам привело к их неэффективности.

Cytokine Profile of CCR6+ T-Helpers Isolated from the Blood of Patients with Peptic Ulcer Associated with Helicobacter pylori Infection

We previously found that the number of CCR6⁺ T-helpers with the phenotype of effector/effector memory T cells increases in the blood of patients with H. pylori-associated peptic ulcer. The mature phenotype and the expression of the chemokine receptor CCR6, which is involved in migration of lymphocytes to the inflamed mucous membrane of the gastrointestinal tract, suggests that these cells are involved in the immune response observed in this clinical condition. To better understand the pathogenetic role of these cells, it is necessary to study their functional activity, specifically, the production of pro-inflammatory cytokines involved in the pathogenesis of the disease.

The aim of the study was to evaluate changes in the blood level of pro-inflammatory types of mature CCR6⁺ T-helpers in H. pylori-associated peptic ulcer disease.

In vitro and in vivo inhibition of Helicobacter pylori by Lactobacillus plantarum pH3A, monolaurin, and grapefruit seed extract

Helicobacter pylori infection is the most common cause of gastritis and gastric ulcers. Considering the severe side effects of current antibiotic therapies, it is crucial to find an alternate treatment for H. pylori infection. In this study, we investigated the anti-H. pylori effects of a newly isolated strain of Lactobacillus plantarum (pH3A), monolaurin, grapefruit seed extract (GSE), and their synergies in vitro and in vivo. Monolaurin and GSE suppressed H. pylori growth and urease activity at a minimal inhibitory concentration (MIC) of 62.5 ppm. Live cells and cell-free culture supernatant (CFCS) of L. plantarum pH3A with or without pH adjustment also significantly inhibited H. pylori growth. Although synergy was not observed between monolaurin and GSE, the addition of CFCS significantly enhanced their anti-H. pylori activities. Moreover, L. plantarum pH3A significantly decreased the ability of H. pylori to adhere to AGS cells and interleukin (IL)-8 production in the H. pylori-stimulated AGS cell line. The addition of GSE or monolaurin strengthened these effects. In the in vivo study, H. pylori colonization of the mouse stomach and total serum IgG production were significantly reduced by L. plantarum pH3A treatment, but the addition of monolaurin or GSE did not contribute to these anti-H. pylori activities. Therefore, the L. plantarum pH3A strain can potentially be applied as an alternative anti-H. pylori therapy, but evidence of its synergy with monolaurin or GSE in vivo is still lacking.

Probiotics as the live microscopic fighters against Helicobacter pylori gastric infections

Background

Helicobacter pylori (H. pylori) is the causative agent of stomach diseases such as duodenal ulcer and gastric cancer, in this regard incomplete eradication of this bacterium has become to a serious concern. Probiotics are a group of the beneficial bacteria which increase the cure rate of H. pylori infections through various mechanisms such as competitive inhibition, co-aggregation ability, enhancing mucus production, production of bacteriocins, and modulating immune response.

Result

In this study, according to the received articles, the anti-H. pylori activities of probiotics were reviewed. Based on studies, administration of standard antibiotic therapy combined with probiotics plays an important role in the effective treatment of H. pylori infection. According to the literature, Lactobacillus casei, Lactobacillus reuteri, Lactobacillus rhamnosus GG, and Saccharomyces boulardii can effectively eradicate H. pylori infection. Our results showed that in addition to decrease gastrointestinal symptoms, probiotics can reduce the side effects of antibiotics (especially diarrhea) by altering the intestinal microbiome.

Conclusion

Nevertheless, antagonist activities of probiotics are H. pylori strain-specific. In general, these bacteria can be used for therapeutic purposes such as adjuvant therapy, drug-delivery system, as well as enhancing immune system against H. pylori infection.

Interplay and cooperation of Helicobacter pylori and gut microbiota in gastric carcinogenesis

Chronic Helicobacter pylori infection is a critical risk factor for gastric cancer (GC). However, only 1-3 % of people with H. pylori develop GC. In gastric carcinogenesis, non-H. pylori bacteria in the stomach might interact with H. pylori. Bacterial dysbiosis in the stomach can strengthen gastric neoplasia development via generating tumor-promoting metabolites, DNA damaging, suppressing antitumor immunity, and activating oncogenic signaling pathways. Other bacterial species may generate short-chain fatty acids like butyrate that may inhibit carcinogenesis and inflammation in the human stomach. The present article aimed at providing a comprehensive overview of the effects of gut microbiota and H. pylori on the development of GC. Next, the potential mechanisms of intestinal microbiota were discussed in gastric carcinogenesis. We also disserted the complicated interactions between H. pylori, intestinal microbiota, and host in gastric carcinogenesis, thus helping us to design new strategies for preventing, diagnosing, and treating GC.

Glycosaminoglycan biosynthesis pathway in host genome is associated with Helicobacter pylori infection

Helicobacter pylori is a causative pathogen of many gastric and extra-gastric diseases. It has infected about half of the global population. There were no genome-wide association studies (GWAS) for H. pylori infection conducted in Chinese population, who carried different and relatively homogenous strain of H. pylori. In this work, we performed SNP (single nucleotide polymorphism)-based, gene-based and pathway-based genome-wide association analyses to investigate the genetic basis of host susceptibility to H. pylori infection in 480 Chinese individuals. We also profiled the composition and function of the gut microbiota between H. pylori infection cases and controls. We found several genes and pathways associated with H. pylori infection (P < 0.05), replicated one previously reported SNP rs10004195 in TLR1 gene region (P = 0.02). We also found that glycosaminoglycan biosynthesis related pathway was associated with both onset and progression of H. pylori infection. In the gut microbiome association study, we identified 2 species, 3 genera and several pathways had differential abundance between H. pylori infected cases and controls. This paper is the first GWAS for H. pylori infection in Chinese population, and we combined the genetic and microbial data to comprehensively discuss the basis of host susceptibility to H. pylori infection.

Impact of Coinfection with Schistosoma mansoni on the Antibody Response to Helicobacter pylori

PURPOSE

In many tropical areas, the coinfection of Schistosoma spp. and other pathogens is frequent. The impact of schistosomiasis on other infections has been demonstrated for several organisms. Infection with the widely spread bacterium, Helicobacter pylori, has been linked to ulcers and tumors of the digestive system with the humoral immune response playing possible modulatory roles. The present study investigated the impact of patent S. mansoni infection on the antibody response to H. pylori.

METHODS

A total of 100 participants from a schistosomiasis endemic area in Egypt were enrolled in the study. Based on the detection of S. mansoni eggs and H. pylori coproantigen in fecal samples, they were equally divided into four groups: schistosomiasis, concomitant S. mansoni and H. pylori infection, H. pylori infection alone, and healthy controls. Anti-H. pylori IgG and IgA were determined in serum samples using ELISA.

RESULTS

A significantly lower IgA seropositivity rate and significantly lower IgG levels were found in patients with concomitant schistosomiasis (Gp2) compared to those infected only with H. pylori (Gp1).

CONCLUSIONS

Concomitant S. mansoni infection with light to moderate intensity alters serological responses to H. pylori. In schistosomiasis endemic areas, the routine examination for H. pylori infection should, therefore, rely on coproantigen level rather than antibody levels. Further studies should investigate histopathological changes and other immunological parameters in coinfection.

Notch Signaling Ligand Jagged1 Enhances Macrophage-Mediated Response to Helicobacter pylori

Helicobacter pylori (H. pylori) is one of the gram-negative bacteria that mainly colonize the stomach mucosa and cause many gastrointestinal diseases, such as gastritis, peptic ulcer, and gastric cancer. Macrophages play a key role in eradicating H. pylori. Recent data have shown that Notch signaling could modulate the activation and bactericidal activities of macrophages. However, the role of Notch signaling in macrophages against H. pylori remains unclear. In the present study, in the co-culture model of macrophages with H. pylori, the inhibition of Notch signaling using γ-secretase decreased the expression of inducible nitric oxide synthase (iNOS) and its product, nitric oxide (NO), and downregulated the secretion of pro-inflammatory cytokine and attenuated phagocytosis and bactericidal activities of macrophages to H. pylori. Furthermore, we identified that Jagged1, one of Notch signaling ligands, was both upregulated in mRNA and protein level in activated macrophages induced by H. pylori. Clinical specimens showed that the number of Jagged1⁺ macrophages in the stomach mucosa from H. pylori-infected patients was significantly higher than that in healthy control. The overexpression of Jagged1 promoted bactericidal activities of macrophages against H. pylori and siRNA-Jagged1 presented the opposite effect. Besides, the addition of exogenous rJagged1 facilitated the pro-inflammatory mediators of macrophages against H. pylori, but the treatment of anti-Jagged1 neutralizing antibody attenuated it. Taken together, these results suggest that Jagged1 is a promoting molecule for macrophages against H. pylori, which will provide insight for exploring Jagged1 as a novel therapeutic target for the control of H. pylori infection.

Helicobacter-stimulated IL-10-producing B cells suppress differentiation of lipopolysaccharide/Helicobacter felis-activated stimulatory dendritic cells

Regulatory B cells (Bregs) produce antiinflammatory cytokines and inhibits proinflammatory response. Recently, immunosuppressive roles of Bregs in the effector functions of dendritic cells (DCs) were demonstrated. However, cross talk between Bregs and DCs in Helicobacter infection remains unknown. Here, we showed that direct stimulation of bone marrow-derived DCs (BM-DCs) with Helicobacter felis (H. felis) antigen upregulates their CD86 surface expression and causes the production of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), interleukin-12 (IL-12), and interleukin-10 (IL-10). Furthermore, prestimulation of DCs with supernatants derived from both Helicobacter-stimulated IL-10^– B (Hf_stim-IL-10^– B) or IL-10⁺ B (Hf_stim-IL-10⁺) cells suppresses the secretion of TNF-α and IL-6, but does not affect the expression of CD86 and secretion of IL-12 by lipopolysaccharide (LPS) or H. felis-activated BM-DCs. Remarkably, soluble factors secreted by Hf_stim-IL-10^– B cells, but not by Hf_stim-IL-10⁺ B cells, suppress the secretion of IL-10 by BM-DCs upon subsequent LPS stimulation. In contrast, prestimulation with BM-DCs with supernatants of Hf_stim-IL-10⁺ B cells before H. felis antigen stimulation induces significantly their IL-10 production. Collectively, our data indicated that prestimulation with soluble factors secreted by Hf_stim-IL-10⁺ B cells, DCs exhibit a tolerogenic phenotype in response to LPS or Helicobacter antigen by secreting high levels of IL-10, but decreased levels of IL-6 and TNF-α.

Immune System Investigation Using Parasitic Helminths

Coevolutionary adaptation between humans and helminths has developed a finely tuned balance between host immunity and chronic parasitism due to immunoregulation. Given that these reciprocal forces drive selection, experimental models of helminth infection are ideally suited for discovering how host protective immune responses adapt to the unique tissue niches inhabited by these large metazoan parasites. This review highlights the key discoveries in the immunology of helminth infection made over the last decade, from innate lymphoid cells to the emerging importance of neuroimmune connections. A particular emphasis is placed on the emerging areas within helminth immunology where the most growth is possible, including the advent of genetic manipulation of parasites to study immunology and the use of engineered T cells for therapeutic options. Lastly,we cover the status of human challenge trials with helminths as treatment for autoimmune disease, which taken together, stand to keep the study of parasitic worms at the forefront of immunology for years to come.

Comprehensive Integration of Genome-Wide Association and Gene Expression Studies Reveals Novel Gene Signatures and Potential Therapeutic Targets for Helicobacter pylori-Induced Gastric Disease

Helicobacter pylori is a gram-negative bacterium that colonizes the human gastric mucosa and can lead to gastric inflammation, ulcers, and stomach cancer. Due to the increase in H. pylori antimicrobial resistance new methods to identify the molecular mechanisms of H. pylori-induced pathology are urgently needed. Here we utilized a computational biology approach, harnessing genome-wide association and gene expression studies to identify genes and pathways determining disease development. We mined gene expression data related to H. pylori-infection and its complications from publicly available databases to identify four human datasets as discovery datasets and used two different multi-cohort analysis pipelines to define a H. pylori-induced gene signature. An initial Helicobacter-signature was curated using the MetaIntegrator pipeline and validated in cell line model datasets. With this approach we identified cell line models that best match gene regulation in human pathology. A second analysis pipeline through NetworkAnalyst was used to refine our initial signature. This approach defined a 55-gene signature that is stably deregulated in disease conditions. The 55-gene signature was validated in datasets from human gastric adenocarcinomas and could separate tumor from normal tissue. As only a small number of H. pylori patients develop cancer, this gene-signature must interact with other host and environmental factors to initiate tumorigenesis. We tested for possible interactions between our curated gene signature and host genomic background mutations and polymorphisms by integrating genome-wide association studies (GWAS) and known oncogenes. We analyzed public databases to identify genes harboring single nucleotide polymorphisms (SNPs) associated with gastric pathologies and driver genes in gastric cancers. Using this approach, we identified 37 genes from GWA studies and 61 oncogenes, which were used with our 55-gene signature to map gene-gene interaction networks. In conclusion, our analysis defines a unique gene signature driven by H. pylori-infection at early phases and that remains relevant through different stages of pathology up to gastric cancer, a stage where H. pylori itself is rarely detectable. Furthermore, this signature elucidates many factors of host gene and pathway regulation in infection and can be used as a target for drug repurposing and testing of infection models suitability to investigate human infection.

Shedding Light on the African Enigma: In Vitro Testing of Homo sapiens-Helicobacter pylori Coevolution

The continuous characterization of genome-wide diversity in population and case–cohort samples, allied to the development of new algorithms, are shedding light on host ancestry impact and selection events on various infectious diseases. Especially interesting are the long-standing associations between humans and certain bacteria, such as the case of Helicobacter pylori, which could have been strong drivers of adaptation leading to coevolution. Some evidence on admixed gastric cancer cohorts have been suggested as supporting Homo-Helicobacter coevolution, but reliable experimental data that control both the bacterium and the host ancestries are lacking. Here, we conducted the first in vitro coinfection assays with dual human- and bacterium-matched and -mismatched ancestries, in African and European backgrounds, to evaluate the genome wide gene expression host response to H. pylori. Our results showed that: (1) the host response to H. pylori infection was greatly shaped by the human ancestry, with variability on innate immune system and metabolism; (2) African human ancestry showed signs of coevolution with H. pylori while European ancestry appeared to be maladapted; and (3) mismatched ancestry did not seem to be an important differentiator of gene expression at the initial stages of infection as assayed here.

Helicobacter pylori diversification during chronic infection within a single host generates sub-populations with distinct phenotypes

Helicobacter pylori chronically infects the stomach of approximately half of the world's population. Manifestation of clinical diseases associated with H. pylori infection, including cancer, is driven by strain properties and host responses; and as chronic infection persists, both are subject to change. Previous studies have documented frequent and extensive within-host bacterial genetic variation. To define how within-host diversity contributes to phenotypes related to H. pylori pathogenesis, this project leverages a collection of 39 clinical isolates acquired prospectively from a single subject at two time points and from multiple gastric sites. During the six years separating collection of these isolates, this individual, initially harboring a duodenal ulcer, progressed to gastric atrophy and concomitant loss of acid secretion. Whole genome sequence analysis identified 1,767 unique single nucleotide polymorphisms (SNPs) across isolates and a nucleotide substitution rate of 1.3x10-4 substitutions/site/year. Gene ontology analysis identified cell envelope genes among the genes with excess accumulation of nonsynonymous SNPs (nSNPs). A maximum likelihood tree based on genetic similarity clusters isolates from each time point separately. Within time points, there is segregation of subgroups with phenotypic differences in bacterial morphology, ability to induce inflammatory cytokines, and mouse colonization. Higher inflammatory cytokine induction in recent isolates maps to shared polymorphisms in the Cag PAI protein, CagY, while rod morphology in a subgroup of recent isolates mapped to eight mutations in three distinct helical cell shape determining (csd) genes. The presence of subgroups with unique genetic and phenotypic properties suggest complex selective forces and multiple niches within the stomach during chronic infection.