Classification of Helicobacter pylori Virulence Factors: Is CagA a Toxin or Not?

T4SEpp: A pipeline integrating protein language models to predict bacterial type IV secreted effectors

Many pathogenic bacteria use type IV secretion systems (T4SSs) to deliver effectors (T4SEs) into the cytoplasm of eukaryotic cells, causing diseases. The identification of effectors is a crucial step in understanding the mechanisms of bacterial pathogenicity, but this remains a major challenge. In this study, we used the full-length embedding features generated by six pre-trained protein language models to train classifiers predicting T4SEs and compared their performance. We integrated three modules into a model called T4SEpp. The first module searched for full-length homologs of known T4SEs, signal sequences, and effector domains; the second module fine-tuned a machine learning model using data for a signal sequence feature; and the third module used the three best-performing pre-trained protein language models. T4SEpp outperformed other state-of-the-art (SOTA) software tools, achieving ∼0.98 accuracy at a high specificity of ∼0.99, based on the assessment of an independent validation dataset. T4SEpp predicted 13 T4SEs from Helicobacter pylori, including the well-known CagA and 12 other potential ones, among which eleven could potentially interact with human proteins. This suggests that these potential T4SEs may be associated with the pathogenicity of H. pylori. Overall, T4SEpp provides a better solution to assist in the identification of bacterial T4SEs and facilitates studies of bacterial pathogenicity. T4SEpp is freely accessible at https://bis.zju.edu.cn/T4SEpp.

Pangenome Analysis of Helicobacter pylori Isolates from Selected Areas of Africa Indicated Diverse Antibiotic Resistance and Virulence Genes

The challenge facing Helicobacter pylori (H. pylori) infection management in some parts of Africa is the evolution of drug-resistant species, the lack of gold standard in diagnostic methods, and the ineffectiveness of current vaccines against the bacteria. It is being established that even though clinical consequences linked to the bacteria vary geographically, there is rather a generic approach to treatment. This situation has remained problematic in the successful fight against the bacteria in parts of Africa. As a result, this study compared the genomes of selected H. pylori isolates from selected areas of Africa and evaluated their virulence and antibiotic drug resistance, those that are highly pathogenic and are associated with specific clinical outcomes and those that are less virulent and rarely associated with clinical outcomes. 146 genomes of H. pylori isolated from selected locations of Africa were sampled, and bioinformatic tools such as Abricate, CARD RGI, MLST, Prokka, Roary, Phandango, Google Sheets, and iTOLS were used to compare the isolates and their antibiotic resistance or susceptibility. Over 20 k virulence and AMR genes were observed. About 95% of the isolates were genetically diverse, 90% of the isolates harbored shell genes, and 50% harbored cloud and core genes. Some isolates did not retain the cagA and vacA genes. Clarithromycin, metronidazole, amoxicillin, and tinidazole were resistant to most AMR genes (vacA, cagA, oip, and bab). Conclusion. This study found both virulence and AMR genes in all H. pylori strains in all the selected geographies around Africa with differing quantities. MLST, Pangenome, and ORF analyses showed disparities among the isolates. This in general could imply diversities in terms of genetics, evolution, and protein production. Therefore, generic administration of antibiotics such as clarithromycin, amoxicillin, and erythromycin as treatment methods in the African subregion could be contributing to the spread of the bacterium's antibiotic resistance.

Hp0521 inhibited the virulence of H. pylori 26,695 strain via regulating CagA expression

Hp0521 is the number of cag pathogenicity island (cagPAI) family in Helicobacter pylori (H. pylori, Hp), which encoded Cag2 protein. The aim of this study was to investigate the role of hp0521 on the H. pylori 26,695 strain. We constructed the recombinant prokaryotic expression plasmid pET-32a-hp0521 and pET-32a-hpc0521. Then, we co-cultured the H. pylori wild strain 26,695 and Δhp0521 strain with GES-1 cells to detect CagA protein transport and IL-8 secretion. We found that Δhp0521 mutation increased the expression of cagA, rpoB and promoted the transportation of CagA protein in GES-1 cells. In addition, we also observed that Δhp0521 mutation had no effect on other cagPAI protein stability and the expression of IL-8. Our findings suggested that hp0521 may down-regulated the expression of cagA, rpoB and inhibited the transportation of CagA protein in GES-1 cells and had no effect on growth.

Microbiota Regulates Pancreatic Cancer Carcinogenesis through Altered Immune Response

The microbiota is present in many parts of the human body and plays essential roles. The most typical case is the occurrence and development of cancer. Pancreatic cancer (PC), one of the most aggressive and lethal types of cancer, has recently attracted the attention of researchers. Recent research has revealed that the microbiota regulates PC carcinogenesis via an altered immune response. Specifically, the microbiota, in several sites, including the oral cavity, gastrointestinal tract, and pancreatic tissue, along with the numerous small molecules and metabolites it produces, influences cancer progression and treatment by activating oncogenic signaling, enhancing oncogenic metabolic pathways, altering cancer cell proliferation, and triggering chronic inflammation that suppresses tumor immunity. Diagnostics and treatments based on or in combination with the microbiota offer novel insights to improve efficiency compared with existing therapies.

Designed Ankyrin Repeat Proteins provide insights into the structure and function of CagI and are potent inhibitors of CagA translocation by the Helicobacter pylori type IV secretion system

The bacterial human pathogen Helicobacter pylori produces a type IV secretion system (cagT4SS) to inject the oncoprotein CagA into gastric cells. The cagT4SS external pilus mediates attachment of the apparatus to the target cell and the delivery of CagA. While the composition of the pilus is unclear, CagI is present at the surface of the bacterium and required for pilus formation. Here, we have investigated the properties of CagI by an integrative structural biology approach. Using Alpha Fold 2 and Small Angle X-ray scattering, it was found that CagI forms elongated dimers mediated by rod-shape N-terminal domains (CagIN) prolonged by globular C-terminal domains (CagIC). Three Designed Ankyrin Repeat Proteins (DARPins) K2, K5 and K8 selected against CagI interacted with CagIC with subnanomolar affinities. The crystal structures of the CagI:K2 and CagI:K5 complexes were solved and identified the interfaces between the molecules, thereby providing a structural explanation for the difference in affinity between the two binders. Purified CagI and CagIC were found to interact with adenocarcinoma gastric (AGS) cells, induced cell spreading and the interaction was inhibited by K2. The same DARPin inhibited CagA translocation by up to 65% in AGS cells while inhibition levels were 40% and 30% with K8 and K5, respectively. Our study suggests that CagIC plays a key role in cagT4SS-mediated CagA translocation and that DARPins targeting CagI represent potent inhibitors of the cagT4SS, a crucial risk factor for gastric cancer development.

Characteristics of different types of Helicobacter pylori: New evidence from non-amplified white light endoscopy

Background

Different types of Helicobacter pylori (H. pylori) were analyzed to determine their infection characteristics using serology, pathology, and non-magnification white light endoscopy combined with the Kimura-Takemoto classification, and the regular arrangement of collecting venules (RAC) as well.

Materials and methods

A retrospective analysis of 685 inpatients who have completed the ¹⁴C-urea breath test, the H. pylori antibody typing classification, the serum gastric function tests (PGI/PGII/G-17), the endoscope detection, and the pathological examinations.

Results

The levels of PGI, PGII, and G-17 were in descending order from the type I H. pylori infection group to the type II H. pylori infection group than the control group (F = 14.31; 26.23; 9.12, P < 0.01). Using the Kimura-Takemoto classification, there were significant differences among the three groups of different degrees of atrophy ( χ 2 =29.81; 482.78; 292.5, P< 0.01). Based on the characteristics of RAC, the H. pylori infection rates were in descending order from the type I H. pylori infection group to the type II H. pylori infection group than the control group ( χ 2 = 200.39; 174.72; 143.51, P < 0.01). The type I H. pylori infection group had higher grades than those of the type II H. pylori infection group in the OLGA and OLGIM staging systems, while the differences are statistically significant only in the OLGA staging system ( χ 2 =10.63, P < 0.05).

Conclusion

With the aid of non-amplified white light endoscopy, we found new evidence of type I H. pylori infection accelerating the progression of gastric mucosal atrophy through the degree of atrophy and the range of infection, whereas type II H. pylori infection has a low ability of migration and atrophy progression. Individual virulence factor-based eradication therapy may be a better choice in future.

An Immune Signature for Risk Stratification and Therapeutic Prediction in Helicobacter pylori-Infected Gastric Cancer

Simple Summary

Helicobacter pylori (HP) infection is the greatest risk factor for gastric cancer (GC), and over half of the world’s population is colonized with HP. Up to now, many gene signatures are designed for predicting the prognosis of GC patients, while there are no signatures designed specifically for HP+ GC patients. Considering the tight association between HP infection and tumor immune microenvironment, we constructed an immune-related signature named IRSHG in this study, aiming to provide new insight into the treatment for HP+ GC patients. IRSHG was the first prognostic signature for HP+ GC patients, demonstrating high reliability and feasibility in predicting the prognosis. In addition, IRSHG could help investigate potential therapies and guide anti-PD-1 immunotherapy for HP+ GC patients, providing new insight for the personalized treatment of GC.

Abstract

Helicobacter pylori (HP) infection is the greatest risk factor for gastric cancer (GC). Increasing evidence has clarified that tumor immune microenvironment (TIME) is closely related to the prognosis and therapeutic efficacy of HP-positive (HP+) GC patients. In this study, we aimed to construct a novel immune-related signature for predicting the prognosis and immunotherapy efficacy of HP+ GC patients. A total of 153 HP+ GC from three different cohorts were included in this study. An Immune-Related prognostic Signature for HP+ GC patients (IRSHG) was established using Univariate Cox regression, the LASSO algorithm, and Multivariate Cox regression. Univariate and Multivariate analyses proved IRSHG was an independent prognostic predictor for HP+ GC patients, and an IRSHG-integrated nomogram was established to quantitatively assessthe prognostic risk. The low-IRSHG group exhibited higher copy number load and distinct mutation profiles compared with the high-IRSHG group. In addition, the difference of hallmark pathways and immune cells infiltration between the two groups was investigated. Notably, tumor immune dysfunction and exclusion (TIDE) analysis indicated that the low-IRSHG group had a higher sensitivity to anti-PD-1 immunotherapy, which was validated by an external pabolizumab treatment cohort. Moreover, 98 chemotherapeutic drugs and corresponding potential biomarkers were identified for two groups, and several drugs with potential ability to reverse IRSHG score were identified using CMap analysis. Collectively, IRSHG may serve as a promising biomarker for survival outcome as well as immunotherapy efficacy. Furthermore, it can also help to prioritize potential therapeutics for HP+ GC patients, providing new insight for the personalized treatment of HP-infected GC.

Implications of Gut Microbiota in Epithelial-Mesenchymal Transition and Cancer Progression: A Concise Review

Simple Summary

Recently, the interactions between microbiota and the host have been reported to induce the onset and progression of human cancer via epithelial–mesenchymal transition (EMT). In contrast, some microorganisms can protect against cancer growth, indicating an anticancer therapeutic action of such microbiota. In the review, we summarize findings from the literature, exploring the underlying mechanisms by which pathogenic microorganisms induce EMT. We also highlight the potential of exploiting these complex interactions for developing new biological therapies.

Abstract

Advancement in the development of molecular sequencing platforms has identified infectious bacteria or viruses that trigger the dysregulation of a set of genes inducing the epithelial–mesenchymal transition (EMT) event. EMT is essential for embryogenesis, wound repair, and organ development; meanwhile, during carcinogenesis, initiation of the EMT can promote cancer progression and metastasis. Recent studies have reported that interactions between the host and dysbiotic microbiota in different tissues and organs, such as the oral and nasal cavities, esophagus, stomach, gut, skin, and the reproductive tract, may provoke EMT. On the other hand, it is revealed that certain microorganisms display a protective role against cancer growth, indicative of possible therapeutic function. In this review, we summarize recent findings elucidating the underlying mechanisms of pathogenic microorganisms, especially the microbiota, in eliciting crucial regulator genes that induce EMT. Such an approach may help explain cancer progression and pave the way for developing novel preventive and therapeutic strategies.

Early and late genome-wide gastric epithelial transcriptome response during infection with the human carcinogen Helicobacterpylori

Infection of the stomach by Helicobacter pylori is a major risk factor for the development of gastric cancer. Colonization of the gastric epithelium leads to the activation of multiple disease-related signaling pathways. Serine protease HtrA represents an important secreted virulence factor that mediates cleavage of cellular junctions. However, its potential role in nuclear responses is unknown. Here, we performed a genome-wide RNA-seq analysis of polarized gastric epithelial cells infected by wild-type (wt) and ΔhtrA mutant bacteria. Fluorescence microscopy showed that H. pylori wt, but not ΔhtrA bacteria, preferably localized at cellular junctions. Our results pinpointed early (2 h) and late (6 h) transcriptional responses, with most differentially expressed genes at 6 h post infection. The transcriptomes revealed HtrA-dependent targeting of genes associated with inflammation and apoptosis (e.g. IL8, ZFP36, TNF). Accordingly, infection with the ΔhtrA mutant induced increased apoptosis rates in host cells, which was associated with reduced H. pylori CagA expression. In contrast, transcription of various carcinogenesis-associated genes (e.g. DKK1, DOCK8) was affected by H. pylori independent of HtrA. These findings suggest that H. pylori disturbs previously unknown molecular pathways in an HtrA-dependent and HtrA-independent manner, and provide valuable new insights of this significant pathogen in humans and thus potential targets for better controlling the risk of malignant transformation.

Prevalence of Virulence Genes and Antigen Pattern in Helicobacter pylori-Infected Patients and The Level of Some Inflammatory Cytokines Compared with Non-infected Individuals

Background: The worldwide prevalence of Helicobacter pylori is about 50%. This bacterium needs a number of virulence factors for pathogenesis. Objectives: This study aimed to determine the prevalence of virulence genes (ureB, cytotoxin-associated gene A [cagA], and vacuolating cytotoxin [vacA]), as well as the antigenic profile in H. pylori strains. Methods: Eighty-five patients with abdominal pain, including 46 H. pylori-positive and 39 H. pylori-negative cases, were enrolled in this study. The serum levels of interleukin (IL)-17F, tumor necrosis factor α (TNF-α), and interferon γ (IFN-γ) cytokines were measured by multiplex kits and flow cytometry. After molecular identification by the ureC gene, vacA, cagA, and ureB genes were detected by polymerase chain reaction (PCR). Finally, after antigenic extraction, the whole-cell protein was exhibited by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE). Results: The prevalence of vacA, ureB, and cagA genes were 91.3%, 67.39%, and 50%, respectively. The frequency of genes and cell surface antigens were not significantly different based on the gastritis severity (P > 0.05). IL-17F significantly (P = 0.046) increased in the presence of 19.5 kDa (outer membrane protein [OMP]). Moreover, the OMP antigen significantly enhanced immunoglobulin A (IgA; P = 0.013). In the presence of the 66-kDa (ureB) antigen, the serum level of IFN-γ increased (p = 0.041). Finally, the CagA protein led to increased IgG antibody levels (p = 0.027). Conclusions: Early detection of H. pylori infection can play a crucial role in managing it. Our results suggest that IL-17F, TNF-α, and IFN-γ cytokines could be diagnostic markers. However, further studies are required to fully investigate this suggestion.

Factors Affect the Eradication Rate of Helicobacter pylori by Modified Quadruple Therapy: A Prospective Cohort Study

Objective

This study aimed to investigate related factors affecting the eradication rate of Helicobacter pylori (Hp) by modified quadruple therapy.

Methods

Between September 2020 and March 2021, 341 patients who were diagnosed with Hp infection and whose infections were confirmed by gastroscopy, a histological examination, and a C13-UBT without culturing and antimicrobial susceptibility studies received a two-week anti-Hp treatment, a modified quadruple therapy, in our department. The result of C13-UBT was rechecked 4 weeks after the drug withdrawal, and the patients were divided into two groups-a success group and a failure group-according to the final breath result. The general clinical information and related laboratory indexes of each patient were collected, and the factors affecting the eradication rate were analyzed.

Results

The total clinical eradication rate was 80.06% (273/341), and the failure rate was 19.94% (68/341), correspondingly. Univariate analysis identified statistically significant differences between the two groups in serum 25-hydroxyvitamin D levels, presence of oral diseases, positive cytotoxin-associated gene A (CagA), and medical compliance (P < 0.05). Meanwhile, the use of a proton pump inhibitor (PPIs) and antibiotics was statistically different (P < 0.05). Logistic regression analysis revealed that vitamin D level (<20 ng/mL) [OR = 98.56, 95% CI (29.01-334.83), P < 0.001] and medical compliance [OR = 148.18, 95% CI (37.64-583.33), P < 0.001] were independent effecting factors for eradication rate.

Conclusion

Serum 25-hydroxyvitamin D level lower than 20 ng/mL may affect the success of eradication of Hp and is an independent risk factor for eradication failure.

Potential Roles of the Gut Microbiota in Pancreatic Carcinogenesis and Therapeutics

The intestinal microenvironment is composed of normal gut microbiota and the environment in which it lives. The largest microecosystem in the human body is the gut microbiota, which is closely related to various diseases of the human body. Pancreatic cancer (PC) is a common malignancy of the digestive system worldwide, and it has a 5-year survival rate of only 5%. Early diagnosis of pancreatic cancer is difficult, so most patients have missed their best opportunity for surgery at the time of diagnosis. However, the etiology is not entirely clear, but there are certain associations between PC and diet, lifestyle, obesity, diabetes and chronic pancreatitis. Many studies have shown that the translocation of the gut microbiota, microbiota dysbiosis, imbalance of the oral microbiota, the interference of normal metabolism function and toxic metabolite products are closely associated with the incidence of PC and influence its prognosis. Therefore, understanding the correlation between the gut microbiota and PC could aid the diagnosis and treatment of PC. Here, we review the correlation between the gut microbiota and PC and the research progresses for the gut microbiota in the diagnosis and treatment of PC.

Helicobacter pylori Pathogenicity Islands and Giardia lamblia Cysteine Proteases in Role of Coinfection and Pathogenesis

Helicobacter pylori is a well-known human-specific stomach pathogen that infects more than half of the world’s population. The infection with this bacterium can cause a variety of gastrointestinal problems, including chronic gastritis, peptic ulcers, and even cancer. H. pylori is a highly infectious bacterium. H. pylori causes an increase in gastric mucosa pH or gastric mucosa intestinal metaplasia. These modifications in the stomach environment are necessary for G. lamblia colonization to occur. Giardia lamblia is a flagellate protozoan parasite that can cause giardiasis in humans and other mammals. It dwells in the duodenum and upper jejunum. Globally, over 280 million cases of human giardiasis are predicted to occur each year. Simultaneous human colonization by G. lamblia and H. pylori is a typical occurrence since the viruses’ predisposing factors are similar in both groups. Giardiasis is a parasitic infection that affects both children and adults worldwide. Infection with Giardia is more common in underdeveloped countries. Globally, more than 200 million cases of giardiasis are detected each year. In contrast, the presence of G. lamblia in the host body triggers an immunological response comparable to that of H. pylori, with lymphocytes strongly polarized towards Th1. As a result, their combined presence exacerbates host tissue damage. The major goal of this seminar is to describe the pathophysiology, immunology, and clinical aspects of G. lamblia and H. pylori coinfection using a comprehensive search of PubMed, Lancet, and Google Scholar sources. Upper gastrointestinal problems such as upper abdominal pain, abdominal bloating, nausea, vomiting, epigastric pain/burning, and belching are all caused by both organisms. Differentiation by physical examination is impossible in people infected with both bacteria. For this coinfection distinction, a laboratory diagnosis is required. G. lamblia and H. pylori, when present together, have a synergistic effect on the host and can cause serious damage. As a result, researchers should delve deeper into the mechanics underlying this potential microbial interaction.

The impacts of probiotics in eradication therapy of Helicobacter pylori

Helicobacter pylori (H. pylori) is a well-known pathogen that infects approximately half of the world's population. It is a pathogenic agent with potential health hazards related to diverse diseases, especially digestive diseases, such as chronic gastritis, peptic ulcer, and gastric carcinoma. In clinical, antibiotics are commonly applied in eradication therapy of H. pylori. However, the increase in antibiotic resistance and side effects has induced the failure of eradication therapy. Recent studies have shown that probiotic supplementation has promising application prospects. It can restore the gastrointestinal microbiota balance and prevent dysbacteriosis caused by antibiotics. Furthermore, it has been reported to have direct or indirect inhibitory effects on H. pylori. Probiotics may have a beneficial effect on H. pylori eradication. However, the strain, dosages, duration times, and safety of probiotic supplementation need further study before clinical applications.

Cortactin Promotes Effective AGS Cell Scattering by Helicobacter pylori CagA, but Not Cellular Vacuolization and Apoptosis Induced by the Vacuolating Cytotoxin VacA

Cortactin is an actin-binding protein and actin-nucleation promoting factor regulating cytoskeletal rearrangements in eukaryotes. Helicobacter pylori is a gastric pathogen that exploits cortactin to its own benefit. During infection of gastric epithelial cells, H. pylori hijacks multiple cellular signaling pathways, leading to the disruption of key cell functions. Two bacterial virulence factors play important roles in this scenario, the vacuolating cytotoxin VacA and the translocated effector protein CagA of the cag type IV secretion system (T4SS). Specifically, by overruling the phosphorylation status of cortactin, H. pylori alternates the activity of molecular interaction partners of this important protein, thereby manipulating the performance of cytoskeletal rearrangements, endosomal trafficking and cell movement. Based on shRNA knockdown and other studies, it was previously reported that VacA utilizes cortactin for its cellular uptake, intracellular travel and induction of apoptosis by a mitochondria-dependent mechanism, while CagA induces cell scattering, motility and elongation. To investigate the role of cortactin in these phenotypes in more detail, we produced a complete knockout mutant of cortactin in the gastric adenocarcinoma cell line AGS by CRISPR-Cas9. These cells were infected with H. pylori wild-type or various isogenic mutant strains. Unexpectedly, cortactin deficiency did not prevent the uptake and formation of VacA-dependent vacuoles, nor the induction of apoptosis by internalized VacA, while the induction of T4SS- and CagA-dependent AGS cell movement and elongation were strongly reduced. Thus, we provide evidence that cortactin is required for the function of internalized CagA, but not VacA.

Colostrum IgA1 antibodies recognize antigens from Helicobacter pylori and prevent cytoskeletal changes in human epithelial cells

Helicobacter pylori is a gram-negative bacterium found on the luminal surface of the gastric mucosa in at least 50% of the world's human population. The protective effect of breastfeeding against H. pylori infection has been extensively reported; however, the mechanisms behind this protection remain poorly understood. Human IgA from colostrum has reactivity against H. pylori antigens. Despite that IgA1 and IgA2 display structural and functional differences, their reactivity against H. pylori had not been previously determined. We attested titers and reactivity of human colostrum-IgA subclasses by ELISA, immunoblot, and flow cytometry. Colostrum samples from healthy mothers had higher titers of IgA; and IgA1 mostly recognized H. pylori antigens. Moreover, we found a correlation between IgA1 reactivity and their neutralizing effect determined by inhibition of cytoskeletal changes in AGS cells infected with H. pylori. In conclusion, colostrum-IgA reduces H. pylori infection of epithelial gastric cells, suggesting an important role in preventing the bacteria establishment during the first months of life. As a whole, these results suggest that IgA1 from human colostrum provides protection that may help in the development of the mucosal immune system of newborn children. This article is protected by copyright. All rights reserved.

Ginger Extract Modulates the Production of Chemokines CCL17, CCL20, CCL22, and CXCL10 and the Gene Expression of Their Receptors in Peripheral Blood Mononuclear Cells from Peptic Ulcer Patients Infected with Helicobacter pylori

Background: The imbalanced expression of chemokines plays critical role in the development of Helicobacter pylori-mediated complications. Objectives: Our aim was to determine ginger extract (GE) effects on the expression of chemokines CCL17, CCL20, CCL22, and CXCL10, as well as CCR4, CCR6, and CXCR3 receptors by peripheral blood mononuclear cells (PBMCs) from H. pylori -infected patients with peptic ulcer (PU). Methods: Peripheral blood mononuclear cells were obtained from 20 patients with H. pylori-associated PU, 20 H. pylori-infected asymptomatic subjects (HAS), and 20 non-infected healthy subjects (NHS). The PBMCs were stimulated by 10 µg/mL of H. pylori-derived crude extract (HPCE) in the presence of 0, 10, 20, and 30 µg/mL of GE. After 36 hours, the supernatant and the RNA extracted from the cells were tested for chemokine concentration and chemokine receptor expression using ELISA and real-time PCR techniques, respectively. Results: In PU patients, treating HPCE-stimulated PBMCs with 10, 20, or 30 µg/mL GE reduced the production of CXCL10 (1.47, 1.5, and 1.53 folds, respectively, P < 0.001 for all), CCL20 (1.44, 1.62, and 1.65 folds, respectively, P < 0.003), and treatment with 30 µg/mL GE increased CCL17 (1.28-fold, P < 0.001) and CCL22 (1.59-fold, P < 0.001) production compared with untreated HPCE-stimulated PBMCs. In PU patients, the HPCE-stimulated PBMCs treated with 10, 20, or 30 µg/mL GE expressed lower levels of CXCR3 (1.9, 3, and 3.5 folds, respectively, P < 0.001) and CCR6 (2.3, 2.7, and 2.8 folds, respectively, P < 0.002) while treating with 10 µg/mL GE upregulated CCR4 (1.7 fold, P = 0.003) compared with untreated HPCE-stimulated PBMCs. Conclusions: Ginger extract modulated the expression of chemokines and their receptors in the PBMCs derived from H. pylori-infected PU patients. The therapeutic potentials of ginger for treating HP-related complications need to be further explored.

Cortactin Is Required for Efficient FAK, Src and Abl Tyrosine Kinase Activation and Phosphorylation of Helicobacter pylori CagA

Cortactin is a well-known regulatory protein of the host actin cytoskeleton and represents an attractive target of microbial pathogens like Helicobacter pylori. H. pylori manipulates cortactin's phosphorylation status by type-IV secretion-dependent injection of its virulence protein CagA. Multiple host tyrosine kinases, like FAK, Src, and Abl, are activated during infection, but the pathway(s) involved is (are) not yet fully established. Among them, Src and Abl target CagA and stimulate tyrosine phosphorylation of the latter at its EPIYA-motifs. To investigate the role of cortactin in more detail, we generated a CRISPR/Cas9 knockout of cortactin in AGS gastric epithelial cells. Surprisingly, we found that FAK, Src, and Abl kinase activities were dramatically downregulated associated with widely diminished CagA phosphorylation in cortactin knockout cells compared to the parental control. Together, we report here a yet unrecognized cortactin-dependent signaling pathway involving FAK, Src, and Abl activation, and controlling efficient phosphorylation of injected CagA during infection. Thus, the cortactin status could serve as a potential new biomarker of gastric cancer development.

Role of the Gastric Microbiome in Gastric Cancer: From Carcinogenesis to Treatment

The development of sequencing technology has expanded our knowledge of the human gastric microbiome, which is now known to play a critical role in the maintenance of homeostasis, while alterations in microbial community composition can promote the development of gastric diseases. Recently, carcinogenic effects of gastric microbiome have received increased attention. Gastric cancer (GC) is one of the most common malignancies worldwide with a high mortality rate. Helicobacter pylori is a well-recognized risk factor for GC. More than half of the global population is infected with H. pylori, which can modulate the acidity of the stomach to alter the gastric microbiome profile, leading to H. pylori-associated diseases. Moreover, there is increasing evidence that bacteria other than H. pylori and their metabolites also contribute to gastric carcinogenesis. Therefore, clarifying the contribution of the gastric microbiome to the development and progression of GC can lead to improvements in prevention, diagnosis, and treatment. In this review, we discuss the current state of knowledge regarding changes in the microbial composition of the stomach caused by H. pylori infection, the carcinogenic effects of H. pylori and non-H. pylori bacteria in GC, as well as the potential therapeutic role of gastric microbiome in H. pylori infection and GC.

Infection with Helicobacter pylori Induces Epithelial to Mesenchymal Transition in Human Cholangiocytes

Recent reports suggest that the East Asian liver fluke infection, caused by Opisthorchis viverrini, which is implicated in opisthorchiasis-associated cholangiocarcinoma, serves as a reservoir of Helicobacter pylori. The opisthorchiasis-affected cholangiocytes that line the intrahepatic biliary tract are considered to be the cell of origin of this malignancy. Here, we investigated interactions in vitro among human cholangiocytes, Helicobacter pylori strain NCTC 11637, and the congeneric bacillus, Helicobacter bilis. Exposure to increasing numbers of H. pylori at 0, 1, 10, 100 bacilli per cholangiocyte of the H69 cell line induced phenotypic changes including the profusion of thread-like filopodia and a loss of cell-cell contact, in a dose-dependent fashion. In parallel, following exposure to H. pylori, changes were evident in levels of mRNA expression of epithelial to mesenchymal transition (EMT)-encoding factors including snail, slug, vimentin, matrix metalloprotease, zinc finger E-box-binding homeobox, and the cancer stem cell marker CD44. Analysis to quantify cellular proliferation, migration, and invasion in real-time by both H69 cholangiocytes and CC-LP-1 line of cholangiocarcinoma cells using the xCELLigence approach and Matrigel matrix revealed that exposure to 10 H. pylori bacilli per cell stimulated migration and invasion by the cholangiocytes. In addition, 10 bacilli of H. pylori stimulated contact-independent colony establishment in soft agar. These findings support the hypothesis that infection by H. pylori contributes to the malignant transformation of the biliary epithelium.

Effects of a Potential Probiotic Strain Lactobacillus gasseri ATCC 33323 on Helicobacter pylori-Induced Inflammatory Response and Gene Expression in Coinfected Gastric Epithelial Cells

In the present study, we aimed to investigate the modulatory effects of a potential probiotic bacterium Lactobacillus gasseri ATCC 33323 on Helicobacter pylori-induced inflammatory response and gene expression in human gastric adenocarcinoma (AGS) cell line. The gastric epithelial cells were coinfected with a collection of H. pylori clinical strains alone or in combination with L. gasseri at a multiplicity of infection (MOI) of 1:100 for each bacterium, and incubated for different time points of 3, 6, and 12 h. IL-8 secretion from coinfected AGS cells after incubation at each time point was measured by an enzyme-linked immunosorbent assay (ELISA). The mRNA expression of IL-8, Bcl-2, β-catenin, integrin α₅, and integrin β₁ genes was determined by quantitative RT-PCR amplification of total RNA extracted from coinfected epithelial cells. L. gasseri significantly (P < 0.05 and P < 0.01) decreased the production of IL-8 in AGS cells coinfected with H. pylori strains at 6 h post-infection. We also detected that L. gasseri significantly (P < 0.05) down-regulated the gene expression level of IL-8 in H. pylori-stimulated AGS cells after 6 and 12 h of coinfection. Similarly, L. gasseri caused a significant decrease (P < 0.05) in mRNA expression of Bcl-2, β-catenin, integrin α₅, and integrin β₁ genes in AGS cells at 3 and 6 h after infection with H. pylori strains as compared with non-infected control cells. In conclusion, our results demonstrated that L. gasseri ameliorates H. pylori-induced inflammation and could be developed as a supplementation to the current treatment regimens administrated against H. pylori infection.

Helicobacter pylori Related Diseases and Osteoporotic Fractures (Narrative Review)

Osteoporosis (OP) and osteoporotic fractures (OFs) are common multifactorial and heterogenic disorders of increasing incidence. Helicobacter pylori (H.p.) colonizes the stomach approximately in half of the world's population, causes gastroduodenal diseases and is prevalent in numerous extra-digestive diseases known to be associated with OP/OF. The studies regarding relationship between H.p. infection (HPI) and OP/OFs are inconsistent. The current review summarizes the relevant literature on the potential role of HPI in OP, falls and OFs and highlights the reasons for controversies in the publications. In the first section, after a brief overview of HPI biological features, we analyze the studies evaluating the association of HPI and bone status. The second part includes data on the prevalence of OP/OFs in HPI-induced gastroduodenal diseases (peptic ulcer, chronic/atrophic gastritis and cancer) and the effects of acid-suppressive drugs. In the next section, we discuss the possible contribution of HPI-associated extra-digestive diseases and medications to OP/OF, focusing on conditions affecting both bone homeostasis and predisposing to falls. In the last section, we describe clinical implications of accumulated data on HPI as a co-factor of OP/OF and present a feasible five-step algorithm for OP/OF risk assessment and management in regard to HPI, emphasizing the importance of an integrative (but differentiated) holistic approach. Increased awareness about the consequences of HPI linked to OP/OF can aid early detection and management. Further research on the HPI-OP/OF relationship is needed to close current knowledge gaps and improve clinical management of both OP/OF and HPI-related disorders.

Whole Genome Sequencing Reveals Virulence Potentials of Helicobacter pylori Strain KE21 Isolated from a Kenyan Patient with Gastric Signet Ring Cell Carcinoma

Helicobacter pylori (H.pylori) infection is etiologically associated with severe diseases including gastric cancer; but its pathogenicity is deeply shaped by the exceptional genomic diversification and geographic variation of the species. The clinical relevance of strains colonizing Africa is still debated. This study aimed to explore genomic features and virulence potentials of H. pylori KE21, a typical African strain isolated from a native Kenyan patient diagnosed with a gastric cancer. A high-quality circular genome assembly of 1,648,327 bp (1590 genes) obtained as a hybrid of Illumina Miseq short reads and Oxford Nanopore MinION long reads, clustered within hpAfrica1 population. This genome revealed a virulome and a mobilome encoding more than hundred features potentiating a successful colonization, persistent infection, and enhanced disease pathogenesis. Furthermore, through an experimental infection of gastric epithelial cell lines, strain KE21 showed the ability to promote interleukin-8 production and to induce cellular alterations resulting from the injection of a functional CagA oncogene protein into the cells. This study shows that strain KE21 is potentially virulent and can trigger oncogenic pathways in gastric epithelial cells. Expended genomic and clinical explorations are required to evaluate the epidemiological importance of H. pylori infection and its putative complications in the study population.

Treatment strategies and preventive methods for drug-resistant Helicobacter pylori infection

The infection and drug resistance rates of Helicobacter pylori (H. pylori) are high and must be prevented and treated by better strategies. Based on recent research advances in this field as well as the results from our team and those on traditional Chinese medicine, we review the causes of drug resistance, and prevention and treatment strategies for drug-resistant H. pylori infection, with an aim to make suggestions for the development of new drugs, such as establishment of new target identification and screening systems, modification of existing drug structures, use of new technologies, application of natural products, and using a commercial compound library. This article may provide reference for eradication of drug-resistant H. pylori.

Global whole family based-Helicobacter pylori eradication strategy to prevent its related diseases and gastric cancer

Helicobacter pylori (H. pylori) infects approximately 50% of the world population. The multiple gastrointestinal and extra-gastrointestinal diseases caused by H. pylori infection pose a major healthcare threat to families and societies; it is also a heavy economic and healthcare burden for countries that having high infection rates. Eradication of H. pylori is recommended for all infected individuals. Traditionally, “test and treat” and "screen and treat" strategies are available for various infected populations. However, clinical practice has noticed that these strategies have some shortfalls and may need refinement, mostly due to the fact that they are not easily manageable, and are affected by patient compliance, selection of treatment population and cost-benefit estimations. Furthermore, it is difficult to control infections from the source, therefore, development of additional, compensative strategies are encouraged to solve the above problems and facilitate bacteria eradication. H. pylori infection is a family-based disease, but few studies have been performed in a whole family-based approach to curb its intra-familial transmission and the development of related diseases. In this work, a third, novel whole family-based H. pylori eradication strategy is introduced. This approach screens, identifies, treats and follows up on all H. pylori-infected individuals in entire families to control H. pylori infection among family members, and reduce its long-term complications. This strategy is high-risk population-oriented, and able to reduce H. pylori spread among family members. It also has good patient-family compliance and, importantly, is practical for both high and low H. pylori-infected communities. Future efforts in these areas will be critical to initiate and establish healthcare policies and management strategies to reduce H. pylori-induced disease burden for society.

Gastric cancer: genome damaged by bugs

Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide. The role of the microorganisms in gastric tumorigenesis attracts much attention in recent years. These microorganisms include bacteria, virus, and fungi. Among them, Helicobacter pylori (H. pylori) infection is by far the most important risk factor for GC development, with special reference to the early-onset cases. H. pylori targets multiple cellular components by utilizing various virulence factors to modulate the host proliferation, apoptosis, migration, and inflammatory response. Epstein–Barr virus (EBV) serves as another major risk factor in gastric carcinogenesis. The virus protein, EBER noncoding RNA, and EBV miRNAs contribute to the tumorigenesis by modulating host genome methylation and gene expression. In this review, we summarized the related reports about the colonized microorganism in the stomach and discussed their specific roles in gastric tumorigenesis. Meanwhile, we highlighted the therapeutic significance of eradicating the microorganisms in GC treatment.

Risk factors associated with gastric malignancy during chronic Helicobacter pylori Infection

Chronic Helicobacter pylori (Hp) infection is considered to be the single most important risk factor for the development of gastric adenocarcinoma in humans, which is a leading cause of cancer-related death worldwide. Nonetheless, Hp infection does not always progress to malignancy, and, gastric adenocarcinoma can occur in the absence of detectable Hp carriage, highlighting the complex and multifactorial nature of gastric cancer. Here we review known contributors to gastric malignancy, including Hp virulence factors, host genetic variation, and multiple environmental variables. In addition, we assess emerging evidence that resident gastric microflora in humans might impact disease progression in Hp-infected individuals. Molecular approaches for microbe identification have revealed differences in the gastric microbiota composition between cancer and non-cancerous patients, as well as infected and uninfected individuals. Although the reasons underlying differences in microbial community structures are not entirely understood, gastric atrophy and hypochlorhydria that accompany chronic Hp infection may be a critical driver of gastric dysbiosis that promote colonization of microbes that contribute to increased risk of malignancy. Defining the importance and role of the gastric microbiota as a potential risk factor for Hp-associated gastric cancer is a vital and exciting area of current research.

Cortactin: A Major Cellular Target of the Gastric Carcinogen Helicobacter pylori

Cortactin is an actin binding protein and actin nucleation promoting factor regulating cytoskeletal rearrangements in nearly all eukaryotic cell types. From this perspective, cortactin poses an attractive target for pathogens to manipulate a given host cell to their own benefit. One of the pathogens following this strategy is Helicobacter pylori, which can cause a variety of gastric diseases and has been shown to be the major risk factor for the onset of gastric cancer. During infection of gastric epithelial cells, H. pylori hijacks the cellular kinase signaling pathways, leading to the disruption of key cell functions. Specifically, by overruling the phosphorylation status of cortactin, H. pylori alternates the activity of molecular interaction partners of this important protein, thereby manipulating the performance of actin-cytoskeletal rearrangements and cell movement. In addition, H. pylori utilizes a unique mechanism to activate focal adhesion kinase, which subsequently prevents host epithelial cells from extensive lifting from the extracellular matrix in order to achieve chronic infection in the human stomach.

Clarithromycin-Susceptible But Virulent Helicobacter pylori Strains Infecting Iranian Patients' Stomachs

Introduction

Helicobacter pylori was discovered first in the stomachs of patients with gastritis and ulcers by Marshall and Warren in 1982. This discovery majorly affected many research areas of gastroenterology. Since then, the main aim has been to eradicate this microaerophilic bacterium from the stomachs of infected subjects.

Methods

We studied symptomatic cases by endoscopic surgery and examined the prevalence of cagA-vacA genotypes among the H. pylori isolates. H. pylori isolated from antral biopsies of patients with gastritis and duodenal ulcer were subjected to antimicrobial susceptibility testing and PCR genotyping by using routine bacterial cultures. Clarithromycin-susceptibility profiling was done by the E-test. DNA was extracted using standard manufacturer protocols with minor modifications and cagA and vacA genotyping was done PCR.

Results

In our study, all strains identified as H. pylori in culture (61/81) were confirmed by PCR by amplifying a fragment of the glmM gene. Totally, 61 patients were confirmed to be positive for H. pylori and they were included in the genotyping and antibiotic-susceptibility testing. Thirteen H. pylori strains were determined to be resistant to clarithromycin.

Discussion

Current accumulating data indicate that both clarithromycin-resistant and susceptible isolates of H. pylori need to be screened and tracked in populations.

CagA Effector Protein in Helicobacter pylori-Infected Human Gastric Epithelium in Vivo: From Bacterial Core and Adhesion/Injection Clusters to Host Cell Proteasome-Rich Cytosol

A key role in the carcinogenic action of Helicobacter pylori is played by the effector protein CagA, the first identified oncoprotein of the bacterial world. However, the present knowledge in regard to the bacterial injection of CagA into epithelial cells (through a type IV secretion system) and its intracellular fate is based primarily on experimental studies in vitro. Our study was aimed to investigate, in H. pylori-infected human gastric epithelium, CagA delivery and intracellular distribution in order to identify any in vivo counterpart of the cell injection mechanism described in vitro and any intracellular cytoplasmic site of preferential CagA distribution, thus shedding light on the natural history of CagA in vivo. By transmission electron microscopy and ultrastructural immunocytochemistry (which combine precise molecule localization with detailed analysis of bacterial-host cell interaction and epithelial cell ultrastructure), we investigated endoscopic biopsies of gastric antrum from H. pylori-infected dyspeptic patients. Our findings provide support for CagA direct injection into gastric epithelial cells at bacterial adhesion sites located on the lateral plasma membrane and for its cytosolic intracellular distribution with selective concentration inside peculiar proteasome-rich areas, which might be site not only of CagA degradation but also of CagA-promoted crucial events in gastric carcinogenesis.