scholarly journals Downregulation of Interleukin- (IL-) 17 through Enhanced Indoleamine 2,3-Dioxygenase (IDO) Induction by Curcumin: A Potential Mechanism of Tolerance towards Helicobacter pylori

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Tiziana Larussa ◽  
Serena Gervasi ◽  
Rita Liparoti ◽  
Evelina Suraci ◽  
Raffaella Marasco ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Antimicrobial Properties ◽  
Human Gastric Mucosa ◽  
T Cell Apoptosis ◽  
Indoleamine 2,3 Dioxygenase ◽  
Treated Sample ◽  
Tryptophan Catabolism ◽  
Gastric Biopsies ◽  
H Pylori

The anti-inflammatory and antimicrobial properties of curcumin suggest its use as an anti-Helicobacter pylori (H. pylori) agent, but mechanisms underlying its helpful activity are still not clear. Indoleamine 2,3-dioxygenase (IDO) promotes the effector T cell apoptosis by catalyzing the rate-limiting first step in tryptophan catabolism, and its high expression in H. pylori-infected human gastric mucosa attenuates Th1 and Th17 immune response. The aim of this study was to investigate the role of curcumin in modulating the expression of IL-17 and IDO in H. pylori-infected human gastric mucosa. In an organ culture chamber, gastric biopsies from 35 patients were treated with and without 200 μM curcumin. In H. pylori-infected patients (n=21), IL-17 was significantly lower, both in gastric biopsies (p=0.0003) and culture supernatant (p=0.0001) while IDO significantly increased (p<0.00001) in curcumin-treated sample compared with untreated samples. In a subgroup of H. pylori-infected patients (n=15), samples treated with curcumin in addition to IDO inhibitor 1-methyl-L-tryptophan (1-MT) showed a higher expression of IL-17 compared with untreated samples and curcumin-treated alone (p<0.00001). Curcumin downregulates IL-17 production through the induction of IDO in H. pylori-infected human gastric mucosa, suggesting its role in dampening H. pylori-induced immune-mediated inflammatory changes.

scholarly journals Interleukin-12 Drives the Th1 Signaling Pathway in Helicobacter pylori-Infected Human Gastric Mucosa

2007 ◽  
Vol 75 (4) ◽  
pp. 1738-1744 ◽  
Author(s):  
Antonia Pellicanò ◽  
Ladislava Sebkova ◽  
Giovanni Monteleone ◽  
Giovanni Guarnieri ◽  
Maria Imeneo ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Transcription Factors ◽  
Gastric Mucosa ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Gastric Mucosa ◽  
Organ Cultures ◽  
Gastric Biopsies ◽  
Ifn Γ ◽  
H Pylori ◽  
Cell Commitment

ABSTRACT In this study we examined mechanisms that regulate T-helper lymphocyte 1 (Th1) commitment in Helicobacter pylori-infected human gastric mucosa. The levels of gamma interferon (IFN-γ), interleukin-4 (IL-4), and IL-12 in total extracts of gastric biopsies taken from H. pylori-infected and uninfected patients were determined by an enzyme-linked immunosorbent assay. The levels of signal transducer and activator of transcription 4 (STAT4), STAT6, and T-box expressed in T cells (T-bet) in total proteins extracted from gastric biopsies were determined by Western blotting. Finally, the effect of a neutralizing IL-12 antibody on expression of Th1 transcription factors and the levels of IFN-γ in organ cultures of H. pylori-infected biopsies was examined. Increased levels of IFN-γ and IL-12 were found in gastric biopsy samples of H. pylori-infected patients compared to the levels in uninfected patients. In addition, H. pylori-infected biopsies exhibited high levels of expression of phosphorylated STAT4 and T-bet. Higher levels of IFN-γ and expression of Th1 transcription factors were associated with greater infiltration of mononuclear cells in the gastric mucosa. By contrast, production of IL-4 and expression of phosphorylated STAT6 were not associated with the intensity of mononuclear cell infiltration. In ex vivo organ cultures of H. pylori-infected biopsies, neutralization of endogenous IL-12 down-regulated the expression of phosphorylated STAT4 and T-bet and reduced IFN-γ production. Our data indicated that IL-12 contributes to the Th1 cell commitment in H. pylori-infected human gastric mucosa.

Helicobacter pylori (H. pylori) infection increases IL-8 and IL-6 production from human gastric mucosa

1995 ◽  
Vol 108 (4) ◽  
pp. A769
Author(s):  
T. Ando ◽  
K. Kusugami ◽  
M. Sakakibara ◽  
T. Shimizu ◽  
M. Shinoda ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Human Gastric Mucosa ◽  
H Pylori

scholarly journals Helicobacter pylori–binding nonacid glycosphingolipids in the human stomach

2018 ◽  
Vol 293 (44) ◽  
pp. 17248-17266 ◽  
Author(s):  
Chunsheng Jin ◽  
Angela Barone ◽  
Thomas Borén ◽  
Susann Teneberg
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Structural Complexity ◽  
Human Stomach ◽  
Carbohydrate Binding ◽  
Human Gastric Mucosa ◽  
H Pylori ◽  
Contrast Information

Helicobacter pylori has a number of well-characterized carbohydrate-binding adhesins (BabA, SabA, and LabA) that promote adhesion to the gastric mucosa. In contrast, information on the glycoconjugates present in the human stomach remains unavailable. Here, we used MS and binding of carbohydrate-recognizing ligands to characterize the glycosphingolipids of three human stomachs from individuals with different blood group phenotypes (O(Rh−)P, A(Rh+)P, and A(Rh+)p), focusing on compounds recognized by H. pylori. We observed a high degree of structural complexity, and the composition of glycosphingolipids differed among individuals with different blood groups. The type 2 chain was the dominating core chain of the complex glycosphingolipids in the human stomach, in contrast to the complex glycosphingolipids in the human small intestine, which have mainly a type 1 core. H. pylori did not bind to the O(Rh−)P stomach glycosphingolipids, whose major complex glycosphingolipids were neolactotetraosylceramide, the Lex, Lea, and H type 2 pentaosylceramides, and the Ley hexaosylceramide. Several H. pylori-binding compounds were present among the A(Rh+)P and A(Rh+)p stomach glycosphingolipids. Ligands for BabA-mediated binding of H. pylori were the Leb hexaosylceramide, the H type 1 pentaosylceramide, and the A type 1/ALeb heptaosylceramide. Additional H. pylori-binding glycosphingolipids recognized by BabA-deficient strains were lactosylceramide, lactotetraosylceramide, the x2 pentaosylceramide, and neolactohexaosylceramide. Our characterization of human gastric receptors required for H. pylori adhesion provides a basis for the development of specific compounds that inhibit the binding of this bacterium to the human gastric mucosa.

scholarly journals Gene structure of the Helicobacter pylori cytotoxin and evidence of its key role in gastric disease.

1994 ◽  
Vol 179 (5) ◽  
pp. 1653-1658 ◽  
Author(s):  
J L Telford ◽  
P Ghiara ◽  
M Dell'Orco ◽  
M Comanducci ◽  
D Burroni ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Peptic Ulcer ◽  
Gastric Mucosa ◽  
Chronic Infection ◽  
Gastric Disease ◽  
Human Gastric Mucosa ◽  
Gastric Lesions ◽  
Gram Negative ◽  
H Pylori ◽  
Cytotoxin Gene

The gram negative, microaerophilic bacterium Helicobacter pylori colonizes the human gastric mucosa and establishes a chronic infection that is tightly associated with atrophic gastritis, peptic ulcer, and gastric carcinoma. Cloning of the H. pylori cytotoxin gene shows that the protein is synthesized as a 140-kD precursor that is processed to a 94-kD fully active toxin. Oral administration to mice of the purified 94-kD protein caused ulceration and gastric lesions that bear some similarities to the pathology observed in humans. The cloning of the cytotoxin gene and the development of a mouse model of human gastric disease will provide the basis for the understanding of H. pylori pathogenesis and the development of therapeutics and vaccines.

scholarly journals Tissue transglutaminase activity in human gastric mucosa according to Helicobacter pylori infection

2018 ◽  
Vol 243 (15-16) ◽  
pp. 1161-1164
Author(s):  
Maria Pina Dore ◽  
Giovanni Mario Pes ◽  
Alessandra Errigo ◽  
Alessandra Manca ◽  
Giuseppe Realdi
Keyword(s):  
Helicobacter Pylori ◽  
Animal Models ◽  
Gastric Mucosa ◽  
Natural History ◽  
Tissue Transglutaminase ◽  
Helicobacter Pylori Infection ◽  
Human Gastric Mucosa ◽  
Antral Mucosa ◽  
History Of ◽  
H Pylori

Tissue transglutaminase (t-TG) is a multifunctional protein involved in the healing of gastric erosions and ulcers in animal models. The aim of this study was to measure gastric t-TG activity in patients with dyspepsia according to Helicobacter pylori infection and cytotoxin-associated gene A (cagA) and vacuolating cytotoxin (vacA) subtype status. Patients undergoing upper endoscopy not taking any medications were enrolled. Tissue-TG activity was determined in homogenates of antral specimens using a radiometric assay and was expressed in pmol/mg. The cagA and vacA genotypes were determined by PCR amplification using gene-specific oligoprimers. Data from 46 patients were available (17 of them were positive for H. pylori). Antral t-TG activity was significantly increased in H. pylori positive patients compared to H. pylori negative patients (6437 ± 3691 vs. 3773 ± 1530 pmol/mg; P = 0.001) according to Mann–Whitney U test. Patients with H. pylori negative gastritis had higher t-TG activity than patients with normal gastric mucosa. The specimens infected with cagA positive strains (72%) displayed greater t-TG activity than cagA negative samples (7358 ± 4318 vs. 4895 ± 1062 pmol/mg; P = 0.237). Similarly, t-TG activity was higher in H. pylori vacA s1/m1 strains vs. vacA s1/m2 (7429 vs. 5045 pmol/mg; P = 0.744), and vacA s1/m1 vs. s2/m2 (7429 vs. 4489 pmol/mg; P = 0.651) but the results were not significant. No differences were found between histology, endoscopy features and t-TG activity. These results show that t-TG activity is significantly greater in gastritis associated with H. pylori infection, suggesting that this enzyme is induced by inflammation and may have an important role in the natural history of human gastritis. Impact statement Tissue transglutaminase (t-TG) is unique among TG enzymes because of its additional role in several physiological and pathological activities, including inflammation, fibrosis, and wound healing. The presence of t-TG has previously been described in the intestine of human and animal models, yet studies on t-TG activity in human gastric mucosa are missing. Helicobacter pylori infection is the major cause of gastritis and peptic ulcers. For the first time, our results show that t-TG activity was significantly higher in antral specimens of patients with chronic active gastritis associated with H. pylori infection compared to H. pylori negative chronic gastritis and normal antral mucosa. These findings suggest that t-TG has a role in the natural history of human gastritis, which requires further investigation but may be an avenue for new therapeutic options.

scholarly journals Variations in Helicobacter pylori Lipopolysaccharide To Evade the Innate Immune Component Surfactant Protein D

2005 ◽  
Vol 73 (11) ◽  
pp. 7677-7686 ◽  
Author(s):  
Wafa Khamri ◽  
Anthony P. Moran ◽  
Mulugeta L. Worku ◽  
Q. Najma Karim ◽  
Marjorie M. Walker ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Phase Variation ◽  
Surfactant Protein ◽  
Clinical Isolates ◽  
Surfactant Protein D ◽  
Human Gastric Mucosa ◽  
H Pylori

ABSTRACT Helicobacter pylori is a common and persistent human pathogen of the gastric mucosa. Surfactant protein D (SP-D), a component of innate immunity, is expressed in the human gastric mucosa and is capable of aggregating H. pylori. Wide variation in the SP-D binding affinity to H. pylori has been observed in clinical isolates and laboratory-adapted strains. The aim of this study was to reveal potential mechanisms responsible for evading SP-D binding and establishing persistent infection. An escape variant, J178V, was generated in vitro, and the lipopolysaccharide (LPS) structure of the variant was compared to that of the parental strain, J178. The genetic basis for structural variation was explored by sequencing LPS biosynthesis genes. SP-D binding to clinical isolates was demonstrated by fluorescence-activated cell sorter analyses. Here, we show that H. pylori evades SP-D binding through phase variation in lipopolysaccharide. This phenomenon is linked to changes in the fucosylation of the O chain, which was concomitant with slipped-strand mispairing in a poly(C) tract of the fucosyltransferase A (fucT1) gene. SP-D binding organisms are predominant in mucus in vivo (P = 0.02), suggesting that SP-D facilitates physical elimination. Phase variation to evade SP-D contributes to the persistence of this common gastric pathogen.

scholarly journals DC-LAMP+Dendritic Cells Are Recruited to Gastric Lymphoid Follicles in Helicobacter pylori-Infected Individuals

2013 ◽  
Vol 81 (10) ◽  
pp. 3684-3692 ◽  
Author(s):  
Malin Hansson ◽  
Malin Sundquist ◽  
Susanne Hering ◽  
B. Samuel Lundin ◽  
Michael Hermansson ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Dendritic Cells ◽  
Gastric Mucosa ◽  
Human Gastric Mucosa ◽  
Lymphoid Follicles ◽  
Content Type ◽  
Ulcer Disease ◽  
Hla Dr ◽  
H Pylori ◽  
Antigen Presenting

ABSTRACTInfection withHelicobacter pyloriis associated with development of ulcer disease and gastrointestinal adenocarcinoma. The infection leads to a large infiltration of immune cells and the formation of organized lymphoid follicles in the human gastric mucosa. Still, the immune system fails to eradicate the bacteria, and the substantial regulatory T cell (Treg) response elicited is probably a major factor permitting bacterial persistence. Dendritic cells (DCs) are professional antigen-presenting cells that can activate naive T cells, and maturation of DCs is crucial for the initiation of primary immune responses. The aim of this study was to investigate the presence and localization of mature human DCs inH. pylori-infected gastric mucosa. Gastric antral biopsy specimens were collected from patients withH. pylori-associated gastritis and healthy volunteers, and antrum tissue was collected from patients undergoing gastric resection. Immunohistochemistry and flow cytometry showed that DCs expressing the maturation marker dendritic cell lysosome-associated membrane glycoprotein (DC-LAMP; CD208) are enriched in theH. pylori-infected gastric mucosa and that these DCs are specifically localized within or close to lymphoid follicles. Gastric DC-LAMP-positive (DC-LAMP+) DCs express CD11c and high levels of HLA-DR but little CD80, CD83, and CD86. Furthermore, immunofluorescence analyses demonstrated that DC-LAMP+DCs are in the same location as FoxP3-positive putative Tregs in the follicles. In conclusion, we show that DC-LAMP+DCs with low costimulatory capacity accumulate in the lymphoid follicles in humanH. pylori-infected gastric tissue, and our results suggest that Treg-DC interactions may promote chronic infection by rendering gastric DCs tolerogenic.

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