Relationship between mucosal TNF-α expression and Th1, Th17, Th22 and Treg responses in Helicobacter pylori infection

Role and mechanism of IL-33 in bacteria infection related gastric cancer continuum: From inflammation to tumor progression

Gastric cancer, a globally prevalent malignant tumor, is characterized by low early diagnosis rate, high metastasis rate, and poor prognosis, particularly in East Asia, Eastern Europe, and South America. Helicobacter pylori (H. pylori) is recognized as the primary risk factor for gastric cancer. However, the fact that fewer than 3 % of infected individuals develop cancer suggests that other bacteria may also influence gastric carcinogenesis. A diverse community of microorganisms may interact with H. pylori, thereby driving disease progression. Here, the role of the cytokine IL-33, a member of the IL-1 family, is scrutinized. Its production can be induced by H. pylori through the activation of specific signaling pathways, and it contributes to the inflammatory environment by promoting the release of pro-inflammatory cytokines. This article reviews the conflicting evidence regarding IL-33's role in the progression from gastritis to gastric cancer and discusses the potential therapeutic implications of targeting the IL-33/ST2 axis, with various antibodies and inhibitors in development or undergoing clinical trials for inflammatory diseases. However, the role of IL-33 in gastric cancer treatment remains to be fully elucidated, with its effects potentially dependent on the cellular context and stage of cancer progression. In summary, this review provides a comprehensive overview of the intricate relationship between gastric microbiota, IL-33, and gastritis - gastric cancer transition, offering insights into potential therapeutic targets and the development of novel treatment strategies.

Developing a potent vaccine against Helicobacter pylori: critical considerations and challenges

Helicobacter pylori (H. pylori) is closely associated with gastric cancer and peptic ulcers. The effectiveness of antibiotic treatment against H. pylori is diminished by the emergence of drug-resistant strains, side effects, high cost and reinfections. Given the circumstances, it is imperative to develop a potent vaccination targeting H. pylori. Understanding H. pylori's pathogenicity and the host's immune response is essential to developing a vaccine. Furthermore, vaccine evaluation necessitates the careful selection of design formulation. This review article aims to provide a concise overview of the considerations involved in selecting the optimal antigen, adjuvant, vaccine delivery system and laboratory animal model for vaccine formulation. Furthermore, we will discuss some significant obstacles in the realm of developing a potent vaccination against H. pylori.

Anti-inflammatory effects of extracellular vesicles and cell-free supernatant derived from Lactobacillus crispatus strain RIGLD-1 on Helicobacter pylori-induced inflammatory response in gastric epithelial cells in vitro

Helicobacter pylori infection is the major risk factor associated with the development of gastric cancer. Currently, administration of standard antibiotic therapy combined with probiotics and postbiotics has gained significant attention in the management of H. pylori infection. In this work, the immunomodulatory effects of Lactobacillus crispatus-derived extracellular vesicles (EVs) and cell-free supernatant (CFS) were investigated on H. pylori-induced inflammatory response in human gastric adenocarcinoma (AGS) cells. L. crispatus-derived EVs were isolated by ultracentrifugation and physically characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Furthermore, the protein content of L. crispatus-derived EVs was also evaluated by SDS-PAGE. Cell viability of AGS cells exposed to varying concentrations of EVs and CFS was assessed by MTT assay. The mRNA expression of IL-1β, IL-6, IL-8, TNF-α, IL-10, and TGF-ß genes was determined by RT-qPCR. ELISA was used for the measurement of IL-8 production in AGS cells. In addition, EVs (50 μg/mL) and CFS modulated the H. pylori-induced inflammation by downregulating the mRNA expression of IL-1β, IL-6, IL-8, and TNF-α, and upregulating the expression of IL-10, and TGF-ß genes in AGS cells. Furthermore, H. pylori-induced IL-8 production was dramatically decreased after treatment with L. crispatus-derived EVs and CFS. In conclusion, our observation suggests for the first time that EVs released by L. crispatus strain RIGLD-1 and its CFS could be recommended as potential therapeutic agents against H. pylori-triggered inflammation.

KDGene: knowledge graph completion for disease gene prediction using interactional tensor decomposition

The accurate identification of disease-associated genes is crucial for understanding the molecular mechanisms underlying various diseases. Most current methods focus on constructing biological networks and utilizing machine learning, particularly deep learning, to identify disease genes. However, these methods overlook complex relations among entities in biological knowledge graphs. Such information has been successfully applied in other areas of life science research, demonstrating their effectiveness. Knowledge graph embedding methods can learn the semantic information of different relations within the knowledge graphs. Nonetheless, the performance of existing representation learning techniques, when applied to domain-specific biological data, remains suboptimal. To solve these problems, we construct a biological knowledge graph centered on diseases and genes, and develop an end-to-end knowledge graph completion framework for disease gene prediction using interactional tensor decomposition named KDGene. KDGene incorporates an interaction module that bridges entity and relation embeddings within tensor decomposition, aiming to improve the representation of semantically similar concepts in specific domains and enhance the ability to accurately predict disease genes. Experimental results show that KDGene significantly outperforms state-of-the-art algorithms, whether existing disease gene prediction methods or knowledge graph embedding methods for general domains. Moreover, the comprehensive biological analysis of the predicted results further validates KDGene's capability to accurately identify new candidate genes. This work proposes a scalable knowledge graph completion framework to identify disease candidate genes, from which the results are promising to provide valuable references for further wet experiments. Data and source codes are available at https://github.com/2020MEAI/KDGene.

The contribution of IL-17A-dependent low LCN2 levels to Helicobacter pylori infection: Insights from clinical and experimental studies

BACKGROUND

Helicobacter pylori (H. pylori) infection is a common bacterial infection that is widespread globally. It is crucial to comprehend the molecular mechanisms that underlie the infection caused by H. pylori in order to devise successful therapeutic approaches. The objective of this study was to examine the involvement of Lipocalin-2 (LCN2) in the development of H. pylori infection.

METHODS

LCN2 expression levels in human gastric mucosa and H. pylori-infected mouse models were analyzed using quantitative PCR and immunohistochemistry methods. The effects of LCN2 on the attachment of H. pylori to gastric mucosa cells were assessed using bacterial culture and fluorescence intensity tests. To investigate the correlation between LCN2, CCL20, and IL-17A, we performed gene expression analysis and measured serum levels.

RESULTS

The findings indicated an increase in LCN2 levels in the gastric mucosa of both patients and mice infected with H. pylori. Blocking the natural LCN2 resulted in an increased attachment of H. pylori to cells in the gastric mucosa. In addition, we noticed that reduced levels of LCN2 promoted the attachment of H. pylori to cells in the gastric mucosa. Furthermore, H. pylori-infected patients exhibited increased expression of both LCN2 and CCL20, and there was a positive correlation between serum levels of CCL20 and LCN2. LCN2 expression was found to depend on the presence of IL-17A, and inhibiting IL-17A led to a higher H. pylori colonization.

CONCLUSION

The persistence of H. pylori infection is facilitated by the presence of low levels of LCN2, which is dependent on IL-17A. This finding offers valuable perspectives for the development of novel therapeutic approaches for H. pylori infection.

Immune Biology and Persistence of Helicobacter pylori in Gastric Diseases

Helicobacter pylori is a prevalent pathogen, which affects more than 40% of the global population. It colonizes the human stomach and persists in its host for several decades or even a lifetime, if left untreated. The persistent infection has been linked to various gastric diseases, including gastritis, peptic ulcers, and an increased risk for gastric cancer. H. pylori infection triggers a strong immune response directed against the bacterium associated with the infiltration of innate phagocytotic immune cells and the induction of a Th1/Th17 response. Even though certain immune cells seem to be capable of controlling the infection, the host is unable to eliminate the bacteria as H. pylori has developed remarkable immune evasion strategies. The bacterium avoids its killing through innate recognition mechanisms and manipulates gastric epithelial cells and immune cells to support its persistence. This chapter focuses on the innate and adaptive immune response induced by H. pylori infection, and immune evasion strategies employed by the bacterium to enable persistent infection.