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Helicobacter pylori (H. pylori)-induced gastric inflammation in the gastric mucosa and significantly increases the risk of developing gastritis and peptic ulcer disease (PUD). The objective of this research is to determine the role of tumor necrosis factor-α (TNF-α) expression in the gastric mucosa of patients with H. pylori-associated gastritis and PUD compared to uninfected patients, and we determined the relation between TNF-α expression and Th1/Th17/Th22, and Treg cells. Fifty-five patients with H. pylori-associated gastritis, 47 patients with H. pylori-associated PUD, and 48 uninfected patients were in this research. Antrum biopsy was used to detect H. pylori, virulence factors and histopathological assessments. Expression of TNF-α in the infected group was significantly higher than the uninfected group. Also, cagA/oipA-positive infected patients induce significantly more TNF-α expression than do cagA/oipA-negative infected patients. Expression of TNF-α was significantly increased in the PUD group than the gastritis group. Notably, TNF-α expression had a significant positive correlation with the frequency of Th1/Th17/Th22 lymphocytes in the PUD group. These findings indicate the importance of increasing TNF-α with Th1, Th17, Th22 responses increase as an important risk factor for PUD in context of H. pylori infection. Key points: Expression of TNF-α was significantly increased in the PUD group than the gastritis group. Notably, TNF-α expression had a significant positive correlation with the frequency of Th1/Th17/Th22 lymphocytes in the PUD group. These findings indicate the importance of increasing TNF-α with Th1, Th17, Th22 responses increase as an important risk factor for PUD in context of H. pylori infection. [ABSTRACT FROM AUTHOR]

Helicobacter pylori ( H. pylori ) colonization induces vigorous innate and specific immune responses; however, the infection does not disappear and a chronic active gastritis continues if left untreated. It has been shown that the topographical pattern and immune response of gastritis are the main reasons for the bacteria persistence and the clinical outcome. Gastritis due to H. pylori is caused by a complicated interaction among a variety of T cell subsets. Regulatory T (Treg) cells suppressing the immune response of antigen-specific T-cells have recently been demonstrated to play a key role in chronic inflammation by immunologic tolerance. Treg cells have been identified as the major regulatory component of the adaptive immune response and being involved in H. pylori -related inflammation and bacterial persistence. There have been many controversies over the role of Treg cells in H. pylori infection. Many studies have shown that the local Treg response protects the gastric mucosa from intensified inflammation and tissue damage, and the risk of H. pylori -associated diseases has an inverse correlation with Treg accumulation, even if the decrease in the inflammatory response is recognized by Treg it causes increase in bacterial density. This paper reviews the role of Treg in different clinical expressions of H. pylori infection. [ABSTRACT FROM AUTHOR]

Indoleamine 2, 3- dioxygenase (IDO) plays an important role in immunosuppressive pathway, as inhibits responses of T cells and promotes immune tolerance. Host response to Helicobacter pylori (H. pylori) is involved in the infection persistence and it is also associated with different clinical outcomes. The aim of this study was to investigate the role of IDO in H. pylori -infected patients with gastritis diseases and peptic ulcer diseases (PUD) through the assessment of the relationship among IDO protein expression and the numbers of T helper (Th)-1, Th17, Th22, and T regulator (Treg) cells. Antrum biopsy was obtained from H. pylori -negative patients (n = 48) and H. pylori -positive subjects (55 patients with gastritis and 47 patients with PUD), for performing H. pylori status and histopathological assessments. IDO protein expression was evaluated by Western blotting. IDO protein expression was significantly higher in gastric biopsies from H. pylori -positive subjects compared to the H. pylori -negative subjects, and also in H. pylori -positive subjects with gastritis disease compared to H. pylori -positive subjects with PUD. Moreover, in H. pylori -positive subjects, a positive correlation was observed between IDO protein expression and the frequency of Treg cells. In addition, a negative correlation was observed between IDO protein expression and the number of Th1, Th17, and Th22. Increased IDO protein expression is able to change the number of Th1, Th17, Th22, and Treg cells and these changes are possibly associated with an increase in the risk of PUD development in H. pylori -infected patients. [ABSTRACT FROM AUTHOR]

Peptic ulcer disease (PUD) is a common disease worldwide moreover known as stomach ulcer or peptic ulcer. Increased the number of T CD4+ helper cells in response to gastric infection by Helicobacter pylori (H. pylori) play an important role in the development of PUD. The aim of this study was to determine the frequency of T-bet+ cells in H. pylori -infection, its interaction with Th17/Treg cells and its association with the clinical consequences of the infection. A total of 63 patients with PUD, 89 patients with gastritis and 48 H. pylori -negative subjects were enrolled in this study. The number of T-bet+ cells were determined by immunohistochemistry. The numbers of T-bet+ cells and INF-γ expression in infected patients were significantly higher than uninfected. Moreover, the number of T-bet+ cells and INF-γ expression in infected patients with PUD were significantly higher than infected patients with gastritis. Additionally, the number of T-bet+ cells and INF-γ expression were found to be inversely correlated with degree of H. pylori density and chronic inflammation score (CIS) in infected patients with gastritis disease, but this correlation was positive in the infected patients with PUD. The number of T-bet+ cells was found to be positively correlated with the number of Th17 cells and inversely correlated with the number of Treg cells in infected patients with gastritis and PUD. Abnormal hyper-activation of T-bet+ cells during H. pylori -infection may lead to tissue damage caused by immunopathologic reactions. [ABSTRACT FROM AUTHOR]

Background During Helicobacter pylori ( H. pylori ) infection CD4 + T cells in the gastric lamina propria are hyporesponsive and polarized by Th1/Th17 cell responses controlled by Treg cells. The objective of this study was to determine the number of Th17 cells in gastric mucosa of patients with gastritis and peptic ulcer and determined the relationship between main virulence factor of H. pylori and Th17 cells. Methods and materials A total of 89 H. pylori -infected gastritis patients, 63 H. pylori -infected peptic ulcer patients and 48 H. pylori -negative non-ulcer dysplasia patients were enrolled in this study. The number of Th17 was determined by immunohistochemistry. IL-8 and IL-17A expressions were determined by real-time polymerase chain reaction (qPCR). Also, the grade of chronic and active inflammation was investigated for involvement according to the density of neutrophils and mononuclear in gastric mucosal crypts, from one to all crypts. Results The number of Th17 cells and the expression of IL-8 and IL-17A in infected patients were significantly higher than uninfected subjects. The number of Th17 cells and the expression of IL-8 and IL-17A in infected patients with peptic ulcer were significantly higher than patients with gastritis. Additionally, the numbers of Th17 cells as well as the expression of IL-8 and IL-17A were positively correlated with the degree of H. pylori density in infected patients with peptic ulcer, while this correlation was negative in infected patients with gastritis. The numbers of Th17 cells as well as the expression of IL-8 and IL-17A were positively correlated with the degree of chronic inflammation. Conclusion The predominant Th17 cell responses may play a role in the pathogenesis of peptic ulcers disease in infected patients. [ABSTRACT FROM AUTHOR]

Helicobacter pylori(H. pylori) infection has been involved in the pathogenesis of most important gastroduodenal diseases. Matrix metalloproteinases (MMPs) are a large family of zincendopeptidases which play important roles in degradation of extracellular matrix (ECM) and various inflammatory diseases. Therefore, we examined MMP-7 mRNA levels in the gastric mucosa of patients withH. pyloriinfection and evaluated the effects of virulence factors, such asvacA(vacuolating cytotoxin A) andcagA(cytotoxin-associated gene), inH. pylori-infected patients upon the MMP-7 mRNA mucosal levels. We also determined the correlation between mucosal MMP-7 mRNA levels and the types of disease. Total RNA was extracted from gastric biopsies of 50H. pylori-infected patients and 50 uninfected individuals. Mucosal MMP-7 mRNA expression level inH. pylori-infected and non-infected gastric biopsies was determined by real-time polymerase chain reaction (PCR). The presences of cagA and vacA virulence factors was evaluated using PCR. MMP-7 expression was significantly higher in biopsies of patients infected withH .pyloricompared to uninfected individuals. In addition, mucosal MMP-7 mRNA expression inH. pylori-infected patients significantly associated with thecagAstatus and the types of disease. Our results suggest that MMP-7 might be involved in the pathogenesis ofH. pylori. Peptic ulcer was associated withcagpathogenicity island-dependent MMP-7 upregulation. [ABSTRACT FROM AUTHOR]

Background Helicobacter pylori ( H. pylori ) chronically colonizes gastric/duodenal mucosa and induces gastroduodenal disease such as gastritis and peptic ulcer and induces vigorous innate and specific immune responses; however, the infection is not removed, a state of chronic active gastritis persists for life if untreated. The objective of this study was to determine the number of regulatory T cells (Tregs) in gastric mucosa of patients with gastritis and peptic ulcer and determined the relationship between main virulence factor of H. pylori and Tregs. Methods and materials A total of 89 patients with gastritis, 63 patients with peptic ulcer and 40 healthy, H. pylori -negative subjects were enrolled in this study. Expression of CD4 and Foxp3 was determined by immunohistochemistry. Antrum biopsy was obtained for detection of H. pylori , bacterial virulence factors and histopathological assessments. TGF-β1, IL-10 and FOXP3 expressions were determined by real-time polymerase chain reaction (qPCR). Results The numbers of CD4 + and Foxp3 + T cells as well as the expression of IL-10, TGF-β1, FOXP3, INF-γ and IL-17A in infected patients were significantly higher than the ones in uninfected patients. Also, the number of CD4 + T cells was independent on the vacuolating cytotoxin A (vacA) and outer inflammatory protein A (oipA), but it was positively correlated with cytotoxin-associated gene A (cagA). Instead, the number of Foxp3 + T cells was dependent on the vacA and oipA, but it was independent on cagA. The number of Foxp3 + T cells and the expression of IL-10, TGF-β1 and FOXP3 in infected patients with gastritis were significantly higher than the ones in infected patients with peptic ulcer. Moreover, the number of CD4 + T cells and the expression of IL-17A and INF-γ was the lowest in the gastritis patients, however, increased progressively in the peptic ulcer patients. Additionally, the numbers of CD4 + and Foxp3 + T cells as well as the expression of IL-10, TGF-β1, FOXP3 and INF-γ were positively correlated with the degree of H. pylori density and chronic inflammation. Conclusion Tregs are positively associated with vacA alleles and oipA status of H. pylori and histological grade but negatively associated with peptic ulcer disease. [ABSTRACT FROM AUTHOR]

Helicobacter pylori ( H. pylor i) usually colonizes the gastric mucosa of more than 50% of the human population, causing an infection that may appear in early childhood and can persist for life. H. pylor i is suggested as the main cause of peptic ulcer and chronic gastritis. It is also associated with gastric cancer. Its severity and symptoms depend on environmental factors, host susceptibility and bacterial components, which allow H. pylori to switch between commensalism and pathogenicity. H. pylori is genetically highly variable, and the variability which affects H. pylori virulence factors might be useful in identifying the strains with different degrees of pathogenicity. The geographic distribution of distinct H. pylori genotypes is largely unknown and should be established. The prevalence of more pathogenic genotypes in certain areas may have important epidemiological consequences. It also might be associated with the severity of H. pylori related diseases in such regions. Given that Iran is located in the Middle East and Asian populations have revealed high levels of gastric cancer, it is of clinical interest to clarify the potential of H. pylori virulence markers in predicting the associated clinical outcomes. In this review, clinical relevance of adhesion molecules and significant virulence factors of H. pylori in Iranian patients with gastrointestinal diseases are discussed in comparison to other countries. [ABSTRACT FROM AUTHOR]