Helicobacter pylori(H. pylori) is a worldwide spread bacterium, co-evolving with humans for at least 100 000 years. Despite the uncertainty about the mode ofH. pyloritransmission, the development of intra-gastric and extra-gastric diseases is attributed to this bacterium. The morphological transformation and production of heterogenic virulence factors enableH. pylorito overcome the harsh stomach environment. Using numerous potent disease-associated virulence factors makesH. pyloria prominent pathogenic bacterium. These bacterial determinants are adhesins (e.g., blood group antigen-binding adhesin (BabA)/sialic acid-binding adhesin (SabA)), enzymes (e.g., urease), toxins (e.g., vacuolating cytotoxin A (VacA)), and effector proteins (e.g., cytotoxin-associated gene A (CagA)) involved in colonisation, immune evasion, and disease induction.H. pylorinot only cleverly evades the immune system but also robustly induces immune responses. This insidious bacterium employs various strategies to evade human innate and adaptive immune responses, leading to a life-long infection. Owing to the alteration of surface molecules, innate immune receptors couldn't recognise this bacterium; moreover, modulation of effector T cells subverts adaptive immune response. Most of the infected humans are asymptomatic and only a few of them present severe clinical outcomes. Therefore, the identification of virulence factors will pave the way for the prediction of infection severity and the development of an effective vaccine.H. pylorivirulence factors are hereby comprehensively reviewed and the bacterium evasion from the immune response is properly discussed.

Helicobacter pylori infection is the principal cause of serious diseases (e.g. gastric cancer and peptic ulcers). Antibiotic therapy is an inadequate strategy in H. pylori eradication because of which vaccination is an inevitable approach. Despite the presence of countless vaccine candidates, current vaccines in clinical trials have performed with poor efficacy which makes vaccination extremely challenging. Remarkable advancements in immunology and pathogenic biology have provided an appropriate opportunity to develop various epitope-based vaccines. The fusion of proper antigens involved in different aspects of H. pylori colonization and pathogenesis as well as peptide linkers and built-in adjuvants results in producing epitope-based vaccines with excellent therapeutic efficacy and negligible adverse effects. Difficulties of the in vitro culture of H. pylori, high genetic variation, and unfavourable immune responses against feeble epitopes in the complete antigen are major drawbacks of current vaccine strategies that epitope-based vaccines may overcome. Besides decreasing the biohazard risk, designing precise formulations, saving time and cost, and induction of maximum immunity with minimum adverse effects are the advantages of epitope-based vaccines. The present article is a comprehensive review of strategies for designing and developing epitope-based vaccines to provide insights into the innovative vaccination against H. pylori.

Background: There are conflicting epidemiological studies regarding the association between selenium (Se) and metabolic disorders. Furthermore, the pathophysiological links between Se and metabolic dysfunction-associated steatotic liver disease (MASLD) have not yet been fully elucidated. Therefore, we evaluated the association between serum Se levels and the clinical features of MASLD and the inflammatory and oxidative stress markers in these patients as potential risk factors for the progression of this disease. Methods: This cross-sectional study involved 150 patients aged 20 to 50 years who were newly diagnosed with MASLD. Oxidative stress was evaluated by measuring serum thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (TAC), and the activities of erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPx). Tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and transforming growth factor beta (TGF-β) were measured as inflammatory markers. A one-way analysis of variance (ANOVA), Pearson chi-square test, Kruskal–Wallis test, and multiple linear regression were employed for data analysis. Results: We observed a significant inverse association between serum Se concentrations and liver steatosis severity in the participants. There was a significant decrease in serum concentrations of insulin and the homeostasis model assessment of insulin resistance (HOMA-IR), triglycerides, TNF-α, and TBARS with ascending quartiles of serum Se. Conversely, the mean serum levels of TAC and erythrocyte GPx activities exhibited a consistent increasing trend in relation to rising serum Se concentrations. However, no significant trends were identified for serum FSG, IL-6, TGF-β, or erythrocyte SOD activities across the varying levels of serum Se. Conclusions: Our results demonstrate that decreased serum selenium levels in Iranian patients with MASLD correlate with elevated inflammatory markers, increased oxidative stress, and more severe liver steatosis.

Background and Objectives: Since vitamin D has been shown to have an important function in the regulation of metabolic pathways, this study aimed to investigate the association between serum levels of vitamin D with a number of metabolic indicators in patients with non-alcoholic fatty liver disease (NAFLD). Materials and Methods: This descriptive study ...