Helicobacter Pylori cagA-positive Strains Research Articles

IL-8 Secreted by Gastric Epithelial Cells Infected with Helicobacter pylori CagA Positive Strains Is a Chemoattractant for Epstein-Barr Virus Infected B Lymphocytes.

Helicobacter pylori and EBV are considered the main risk factors in developing gastric cancer. Both pathogens establish life-lasting infections and both are considered carcinogenic in humans. Different lines of evidence support that both pathogens cooperate to damage the gastric mucosa. Helicobacter pylori CagA positive virulent strains induce the gastric epithelial cells to secrete IL-8, which is a potent chemoattractant for neutrophils and one of the most important chemokines for the bacterium-induced chronic gastric inflammation. EBV is a lymphotropic virus that persists in memory B cells. The mechanism by which EBV reaches, infects and persists in the gastric epithelium is not presently understood. In this study, we assessed whether Helicobacter pylori infection would facilitate the chemoattraction of EBV-infected B lymphocytes. We identified IL-8 as a powerful chemoattractant for EBV-infected B lymphocytes, and CXCR2 as the main IL-8 receptor whose expression is induced by the EBV in infected B lymphocytes. The inhibition of expression and/or function of IL-8 and CXCR2 reduced the ERK1/2 and p38 MAPK signaling and the chemoattraction of EBV-infected B lymphocytes. We propose that IL-8 at least partially explains the arrival of EBV-infected B lymphocytes to the gastric mucosa, and that this illustrates a mechanism of interaction between Helicobacter pylori and EBV.

Use of sodium polyprenylphosphate to correct changes in the immune response caused by Helicobacter pylori CagA proteins in the experiment

Helicobacter pylori (HP) bacteria have a wide range of pathogenicity factors. The HP genome contains genes of the CagA group (cytotoxin-associated genes). Infection with CagA-positive HP strains is associated with the production of pro-inflammatory cytokines, which are involved in the maintenance and development of destructive and inflammatory changes in the organism. Here we studied the role of CagA proteins in the regulation of the immune response in DBA mice and evaluated the corrective effect of polyprenyl phosphate (PP) on this process. Genetically modified strains of E. coli were used, differing by the presence of an island of genes encoding the synthesis of HP CagA proteins. The drug Phosprenyl was used as a source of PP. The subpopulation composition of spleen cells was evaluated by flow cytofluorimetry using monoclonal antibodies. The level of IL 10, TGF-β in blood serum was determined by the enzyme immunoassay. The proliferative activity of splenocytes was measured by the standard procedure based on the inclusion of 3 H-thymidine in the DNA. CagA HP proteins caused the polarization of the immune response by the Th1-dominant type, which was expressed by an increase in the population of CD4 + cells, CD25 + and CD25 + Foxp3 + T cells and increase proliferation T- limphocytes. Inoculation of CagA + bacteria was accompanied by a quantitative increase in TGF-β produced by activated Treg cells. PP inoculation led to the normalization of the CD4 and CD8 T cells, a decrease in the populations of CD25 + , Foxp3 + , CD25 + Foxp3 + cells, and further increase in the IL-10 levels. Thus, PP corrected cellular immune response, prevented the pronounced polarization of the Th1 immune response, and reduced the activation of Treg population. The results obtained indicate a possible decrease in the pro-inflammatory immune response under the influence of PP.

Transgenically expressed Helicobacter pylori CagA in vascular endothelial cells accelerates arteriosclerosis in mice

Arteriosclerosis is intimately associated with cardiovascular diseases. Recently, evidence accumulated that infection with Helicobacter pylori cagA-positive strains, which causes gastritis, peptic ulceration, and gastric cancer, is also involved in the development of arteriosclerosis. The cagA-encoded CagA protein is injected into the attached gastric epithelial cells via the type IV secretion system. We previously showed that CagA-containing exosomes are secreted from CagA-injected gastric epithelial cells and enter the systemic blood circulation, delivering CagA into endothelial cells. In the present study, transgenic mice were established in which CagA was selectively expressed in endothelial cells by Cre-loxP system. Treatment of the mice with a high-fat diet revealed that atherogenic lesions were induced in mice expressing CagA in vascular endothelial cells but not in CagA-nonexpressing mice. To investigate the effects of CagA on endothelial cells, we also established conditional CagA-expressing human vascular endothelial cells using the Tet-on system. Upon induction of CagA, a dramatic change in cell morphology was observed that was concomitantly associated with the loss of the endothelial cells to form tube-like structures. Induction of CagA also activated the pro-inflammatory transcription factor STAT3. Thus, exosome-delivered CagA deregulates signals that activates STAT3 in endothelial cells, which accelerates inflammation that promotes arteriosclerosis/atherosclerosis.

Variable frequencies of t(11;18)(q21;q21) in MALT lymphomas of different sites: significant association with CagA strains of H pylori in gastric MALT lymphoma

Abstractt(11;18)(q21;q21) is a specific chromosomal translocation associated with mucosa-associated lymphoid tissue (MALT) lymphoma. It fuses the amino terminal of the API2 gene to the carboxyl terminal of the MALT1 gene and generates a chimeric fusion product. Although the translocation is frequently detected in gastric and pulmonary MALT lymphoma, its incidence in MALT lymphomas from other sites is largely unknown. It also remains unknown whether the occurrence of the translocation is influenced by the nature of preceding diseases associated with MALT lymphomas. We screened for t(11; 18)(q21;q21) in 417 cases of MALT lymphoma from 8 major sites by reverse transcription–polymerase chain reaction. t(11;18)(q21;q21) was found at highest frequencies in MALT lymphomas from the lung (38%) and stomach (24%), and at moderate frequencies in those from the conjunctiva (19%) and orbit (14%). However, the translocation was found only rarely in MALT lymphomas from the salivary gland (1%) and was absent in those from the thyroid, skin, liver, and other rare sites, and in immunoproliferative small intestinal disease (IPSID). In gastric MALT lymphoma, t(11;18)(q21;q21) was significantly associated with infection by CagA-positive strains of Helicobacter pylori. As CagA-positive strains of H pylori are much more potent in induction of host inflammatory responses, including activation of neutrophils, which release highly genotoxic oxygen reactive species, we therefore examined neutrophil infiltration in recognized precursors of MALT lymphoma including H pylori–associated gastritis, lymphoepithelial sialadenitis, and Hashimoto thyroiditis. Neutrophil infiltration was prominent in H pylori–associated gastritis but not in lymphoepithelial sialadenitis and Hashimoto thyroiditis. Our results demonstrate that t(11;18)(q21; q21) occurs at markedly variable frequencies in MALT lymphoma of different sites and suggest that the occurrence of the translocation is influenced by the nature of premalignant diseases associated with MALT lymphoma. Oxidative damage might play a role in development of t(11;18)(q21; q21).

Antibodies crossreacting with human TNF-alfa receptor induced in the patients with coronary heart disease by Helicobacter pylori CagA positive strains

Abstract Introduction Coronary heart disease (CHD) is associated with inflammation and atherosclerosis. The hypothesis of autoimmune origin of CHD has been suggested. Chronic infection with gastric pathogen Helicobacter pylori may induce antibodies, potentially autoreactive, due to molecular mimicry between H. pylori cytotoxin associated gene A (CagA) protein and tumor necrosis factor (TNF)-α receptor (TNFR). Purpose To evaluate presence of antibodies against synthetic c peptide (P1), which mimics the common sequence of TNFR and H. pylori CagA, in the sera of CHD patients and healthy donors (HD), uninfected or infected with H. pylori. Furthermore, guinea pigs (Caviae porcellus), sensitive to H. pylori infection, were used to confirm the induction of antibodies crossreacting with TNFR by this pathogen. Material and methods Serum samples from CHD patients infected with H. pylori CagA(+) strain (43) or H.pylori CagA(−) strain (12), and uninfected HD (16) without symptoms of gastritis or CHD were selected. Moreover, the serum samples from control (10) or H. pylori infected guinea pigs, 7, 28 and 60 days from inoculation were used (10, 20, 10, respectively). The H. pylori status in humans was confirmed by 13C urea breath testing and anti-H. pylori antibody production whereas in Cavia porcellus by histological examination of gastric tissue, detection of H. pylori antigens in stool as well as serum anti-H. pylori antibodies. The ELISA assay with the surface H. pylori antigens – glycine acid extract (GE), recombinant CagA (IRIS, Siena, Italy), synthetic P1 or P2 peptides (Lipopharm, Gdansk, Poland), with or without common CagA/TNFR sequence, respectively, were used for detection of antibodies. Complement activation by P1-anti-P1 IgG complexes was determined by complement fixation assay with sheep erythrocytes (SRBC) and anti-SRBC antibodies. Results :Anti-P1 IgG were detected only in CHD patients infected with H. pylori CagA(+) but not CagA(−) strain. Such antibodies were not detected in H. pylori uninfected HD. Anti-P1 IgG were found in the sera of Cavia porcellus infected with H. pylori, 7 and 28 but not 60 days from inoculation. This may suggest the clearance of such antibodies during the course of infection or their early deposition. The role of H. pylori in anti-P1 IgG induction was confirmed by deletion of such antibodies by absorption of sera, which were positive for anti-P1 IgG, with heat inactivated H. pylori. Anti-P1 IgG present in human and animal sera were biologically active. They formed the immune complexes (IC) with P1 in vitro, which were able to activate complement, suggesting a pro-inflammatory potential of such IC in vivo. Conclusions During H. pylori infection in CHD patients the CagA protein of this pathogen may induce antibodies cross reacting with TNFR. They can potentially increase the inflammatory response by IC dependent activation of complement or due to modulation of TNFR-driven cell signaling pathways. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Statutory Fund of University of Lodz, Poland

Association between polymorphisms in HLA-A, HLA-B, HLA-DR, and DQ genes from gastric cancer and duodenal ulcer patients and cagL among cagA-positive Helicobacter pylori strains: The first study in a Turkish population

Colonization of the human gastric mucosa by H. pylori may cause peptic and duodenal ulcers (DUs), gastric lymphomas, and gastric cancers. The cagL gene is a component of cag T4SS and is involved in cagA translocation into host. An association between the risk of gastric cancer and the type of HLA class II (DR and/or DQ) was suggested in different populations. The aim of this study was to investigate, the clinical association of the cagL gene with host HLA alleles in H. pylori strains that were isolated from patients with gastric cancer, DU, and non-ulcer dyspepsia (NUD) and to determine the HLA allele that confers susceptibility or resistance for the risk of gastric cancer and DU development in Turkish patients.A total of 94 patients (44 gastric cancer and 50 DU patients; 58 male, 36 female; mean age, 49.6 years), and 86 individuals (50 NUD patients and 36 persons with normal gastrointestinal system [NGIS]; 30 male, 56 female; mean age, 47.3 years) were included as the patient and the control groups, respectively. CagA and cagL were determined by PCR method. DNA from peripheral blood samples was obtained by EZ-DNA extraction kit. For HLA SSO typing, LIFECODES SSO Typing kits (HLA-A, HLA-B HLA-C, HLA-DRB1 and HLA-DQA1/B1 kits) were used.The CagL/CagA positivity distribution in the groups were as follows: 42 (95.4%) gastric cancer, 46 (92%) DU and, 34 (68%) NUD and no NGIS cases. The HLA-DQA1*01 (OR: 3.82) allele was significantly different, suggesting that these individuals with H. pylori strains harbouring the CagL/CagA positivity are susceptible to the risk of gastric cancer and DU, and the HLA-DQA1*05 (OR, 0.318) allele was suggested as a protective allele for the risk of gastric cancer and DU using univariate analyses. HLA-DQA1*01 (OR, 2.21), HLA-DQB1*06 (OR, 2.67), sex (male, OR, 2.27), and CagL/CagA/(<2) EPIYA C repeats (OR, 5.72) were detected independent risk factors that increased the risk of gastric cancer and DU using multivariate analyses. However, the HLA-DRB1*04 (OR, 0.28) allele was shown to be a protective allele, which decreased the risk of gastric cancer and DU.Gastric pathologies result from an interaction between bacterial virulence factors, host epigenetic and environmental factors, and H. pylori strain heterogeneity, such as genotypic variation among strains and variations in H. pylori populations within an individual host.

Intramolecular energies of the cytotoxic protein CagA of Helicobacter pylori as a possible descriptor of strains’ pathogenicity level

The Helicobacter pylori cytotoxin-associated gene A (CagA) is known for causing gastroduodenal diseases, such as atrophic gastritis and peptic ulcerations. Furthermore Helicobacter pylori CagA positive strains has been reported as one of the main risk factors for gastric cancer (Parsonnet et al., 1997). Structural variations in the CagA structure can alter its affinity with the host proteins, inducing differences in the pathogenicity of H. pylori. CagA N-terminal region is characterized for be conserved among all H. pylori strains since the C-terminal region is characterized by an intrinsically disorder behavior. We generated complete structural models of CagA using different conformations of the C-terminal region for two H. pylori strains. These models contain the same EPIYA (ABC1C2) motifs but different level of pathogenicity: gastric cancer and duodenal ulcer. Using these structural models we evaluated the pathogenicity level of the H. pylori strain, based on the affinity of the interaction with SHP-2 and Grb2 receptors and on the number of interactions with the EPIYA motif. We found that the main differences in the interaction was due to the contributions of certain types of energies from each strain and not from the total energy of the molecule. Specifically, the electrostatic energy, helix dipole energy, Wander Waals clashes, torsional clash, backbone clash and cis bond energy allowed a separation between severe and mild pathology for the interaction of only CagA with SHP2.

Structure and function of Helicobacter pylori CagA, the first-identified bacterial protein involved in human cancer.

Chronic infection with Helicobacter pylori cagA-positive strains is the strongest risk factor of gastric cancer. The cagA gene-encoded CagA protein is delivered into gastric epithelial cells via bacterial type IV secretion, where it undergoes tyrosine phosphorylation at the Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs. Delivered CagA then acts as a non-physiological scaffold/hub protein by interacting with multiple host signaling molecules, most notably the pro-oncogenic phosphatase SHP2 and the polarity-regulating kinase PAR1/MARK, in both tyrosine phosphorylation-dependent and -independent manners. CagA-mediated manipulation of intracellular signaling promotes neoplastic transformation of gastric epithelial cells. Transgenic expression of CagA in experimental animals has confirmed the oncogenic potential of the bacterial protein. Structural polymorphism of CagA influences its scaffold function, which may underlie the geographic difference in the incidence of gastric cancer. Since CagA is no longer required for the maintenance of established gastric cancer cells, studying the role of CagA during neoplastic transformation will provide an excellent opportunity to understand molecular processes underlying “Hit-and-Run” carcinogenesis.

Helicobacter Pylori Infection: Association with Hashimoto’s Thyroiditis

Autoimmune thyroid diseases (ATDS) are multifactorial conditions that result from genetic predisposition in combination with environmental risk factors. Helicobacter Pylori (HP) infection as an environmental risk factor has been proposed to initiate the antigenic components of the thyroid cell membrane and may play a leading role in the onset of the auto immune diseases such as Hashimoto's thyroiditis (HT). 1.1. The Aim: To investigate the association between H.P infection and HT and the prevalence of cag. A positive strains H.P in the patients. 1.2. Methods:The study include 40 female patients with Hashimoto's thyroiditis as a case group and 30 healthy female as control group. HP antigen in stool samples using unamplified enzyme immunoassay and Cag. Ainserum samples using an enzyme linked immunoassay method (ELISA). Anti-thyroid peroxidase antibodies (anti TPO) and thyroid function tests thyroid stimulating hormone (TSH) and thyroxine (T4) were determined. 1.3. Results:There is statistically significant association between H P and HT (Odd ratio = 8.1, 95% confidence interval: 3-30.1, p<0.001). Also statistically significant association between presence of Cag-A positive strains of HP and HT (odd ratio=5.3, p=0.001). To establish the significant correlation between HP and HT further and more specialized studies are needed. 1.4. Conclusion:There was a significant association between Hashimoto's thyroiditis and H.P infection and significant prevalence of cag. A positive strain of H.P positive patients and HT

Host SHP1 phosphatase antagonizes Helicobacter pylori CagA and can be downregulated by Epstein-Barr virus.

Most if not all gastric cancers are associated with chronic infection of the stomach mucosa with Helicobacter pylori cagA-positive strains(1-4). Approximately 10% of gastric cancers also harbour Epstein-Barr virus (EBV) in the cancer cells(5,6). Following delivery into gastric epithelial cells via type IV secretion(7,8), the cagA-encoded CagA protein undergoes tyrosine phosphorylation on the Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs initially by Src family kinases (SFKs) and then by c-Abl(9,10). Tyrosine-phosphorylated CagA binds to the pro-oncogenic protein tyrosine phosphatase SHP2 and thereby deregulates the phosphatase activity(11,12), which has been considered to play an important role in gastric carcinogenesis(13). Here we show that the SHP2 homologue SHP1 interacts with CagA independently of the EPIYA motif. The interaction potentiates the phosphatase activity of SHP1 that dampens the oncogenic action of CagA by dephosphorylating the CagA EPIYA motifs. In vitro infection of gastric epithelial cells with EBV induces SHP1 promoter hypermethylation, which strengthens phosphorylation-dependent CagA action via epigenetic downregulation of SHP1 expression. Clinical specimens of EBV-positive gastric cancers also exhibit SHP1 hypermethylation with reduced SHP1 expression. The results reveal that SHP1 is the long-sought phosphatase that can antagonize CagA. Augmented H. pylori CagA activity, via SHP1 inhibition, might also contribute to the development of EBV-positive gastric cancer.

Cytotoxin-associated gene antigen-positive strains of Helicobacter pylori and recurring acute coronary syndromes.

Cytotoxin-associated gene antigen (CagA)-positive strains of Helicobacter pylori have previously been associated with acute coronary syndromes. However, the role of CagA-positive strains of Helicobacter pylori in recurring cardiac events after ST-segment elevation myocardial infarction (STEMI) has not yet been assessed. We enrolled 181 consecutive patients (155 men, mean age 64±13 years) presenting with STEMI. In all patients, serum levels of IgG anti-CagA were assessed. Levels of IgG anti-hepatitis A virus were also evaluated in all patients in order to exclude the presence of a bystander activation of the immune system. Finally, a previous history of acute coronary syndrome and the rate of major adverse cardiovascular events as a composite of cardiovascular death, recurring myocardial infarction and target lesion revascularisation within 2 years follow-up were evaluated. Anti-CagA IgG seropositive patients presented more frequently with a previous history of acute coronary syndrome compared with seronegative patients (28.3% vs. 14%, P=0.019). Interestingly, no differences were observed between anti-CagA IgG seropositive and anti-CagA IgG seronegative patients concerning the prevalence of anti-hepatitis A virus IgG seropositivity (20% vs. 21.4%, P=0.48). At 2-year follow-up, 40 patients experienced major adverse cardiovascular events. The major adverse cardiovascular event rate was higher in anti-CagA IgG seropositive compared with seronegative patients (hazard ratio 2.25, 95% confidence interval 1.34-2.95, P=0.013), which was confirmed at Cox multivariate analysis (hazard ratio 2.33, 95% confidence interval 1.30-3.14, P=0.009). CagA-positive strains of Helicobacter pylori seem to be involved in the pathogenesis of recurring acute coronary syndromes, and seropositivity for anti-CagA IgG predicts prognosis after STEMI, possibly due to the increased risk of recurring cardiac events.

Patterns of EPIYA motifs among cagA-positive Helicobacter pylori strains: a case-control study in a Turkish population with Eurasian geographical features.

Geographical variation in the frequency of various gastroduodenal pathologies was shown to be related to the geographical diversity of H. pylori CagA Glu-Pro-Ile-Tyr-Ala (EPIYA) patterns. We examined the EPIYA patterns of H. pylori and the association of EPIYA patterns with gastric cancer (GC) for the first time, to the best of our knowledge, in Turkey. The patient group (PG) contained 60 patients [38 GC and 22 duodenal ulcer (DU) patients]. The control group (CG) was 110 individuals [94 gastritis patients and 16 persons with a normal gastrointestinal system (NGIS)]. Specific primers were used for the detection of cagA including empty-site-positive and EPIYA-A, -B, -C, -D PCR. Bands of EPIYA-A, -B, -C were confirmed by DNA sequencing. One hundred and forty-two (83.5 %) strains [60 in the PG (38 GC, 22 DU), 82 in the CG (72 gastritis, 10 NGIS)] were positive for the cagA gene. EPIYA-C with multiple repeats was detected in 34 (23.9 %) strains, and 22 (64.7 %) were from GC patients. EPIYA-C with one repeat was detected in 89 (62.7 %) strains, and 54 (60.7 %) were from gastritis patients. EPIYT was detected in 10 strains, and EPIYA-D was not detected. The number of EPIYA-C with multiple repeats was significantly higher for the PG than for the CG (P < 0.0001). In GC patients, the number of EPIYA-C with multiple repeats was significantly higher than one repeat (P < 0.0001). In conclusion, our study showed that multiple EPIYA-C repeats increases the GC risk by 30.6-fold and the DU risk by 8.9-fold versus the CG. This indicates that Western-type H. pylori strains in Turkey have similar EPIYA motifs to those of neighbouring countries and Western populations.

Study of the oipA genetic diversity and EPIYA motif patterns in cagA-positive Helicobacter pylori strains from Venezuelan patients with chronic gastritis

CagA and OipA are involved, among other virulence factors, in the ability of Helicobacter pylori to colonize the gastric mucosa and to modulate the host environment during the establishment of chronic infection. The number and type of EPIYA phosphorylation motifs and the presence and functional status of oipA have been involved in the induction of cellular transformations playing an important role in the development of H. pylori associated gastric diseases. This work determined the prevalence of the oipA virulence factor and EPIYA motif patterns in cagA-positive H. pylori gastric biopsies from chronic gastritis patients from the Central-Western region of Venezuela. DNA was extracted directly from gastric biopsies collected by upper endoscopy from 113 patients. The EPIYA motif genotyping and oipA gene functional status was determined by PCR and sequencing. Phylogenetic analysis with the 3′ variable region of cagA sequences was performed. Only Western-type EPIYA variants were detected: ABC (68.14%), ABCC (29.20%) and ABCCC (2.66%). High prevalence of strains with the oipA gene (93.8%) and its functional status “ON” (83%) was observed. No significant association between EPIYA motif patterns or oipA functional status with the histological changes in the gastric mucosa was found. Our study demonstrated the absolute predominance of the Western-type cagA gene in a Venezuelan admixed population. This is the first report showing oipA status of H. pylori strains in Venezuela. Further studies with a larger number of samples and including other pathologies are necessary to continue evaluating the role of the H. pylori virulence factors in the prevalence of gastric diseases in our country.

Particularities of gastroduodenal pathology in children, associated with cytotoxic CAGA-positive strains of Helicobacter pylori.

The aim of the study was to investigate the characteristics of inflammatory gastroduodenal diseases in children, associated with CagA-positive strains of H. pylori. We observed 283 children aged 7 to 17 years with chronic gastroduodenal pathology in exacerbation stage; endoscopic examination of the esophagus, stomach and duodenum was performed, total Ig M, A, G to Ag SagA H. pylori protein in blood serum by ELISA was determined. The study group included 156 patients infected with cytotoxic CagA (+) strains of H. pylori (H. pylori-positive status), comparison group - 59 (20,9%) patients with H. pylori-negative status. It was shown that 55.1% of patients observed were infected with cytotoxic CagA (+) strains of H. pylori. The intensity of clinical symptoms and the severity of inflammatory changes in stomach and duodenum mucosa in children with H. pylori infection is associated with cytotoxic strains of CAG A H. pylori. Presence of extensive gastritis (34,6%; p<0,05), lymphoid hyperplasia (16,0%; p <0,05), turbid mucus in the gastric lumen are the special features of endoscopic changes in children with H. pylori-positive status.

Higher Circulating Levels of Anti-Phosphatidylserine Antibody in Peptic Ulcer Patients Infected with CagA-Positive Strains of Helicobacter pylori

The CagA-positive strains of H. pylori were associated with the higher risk of peptic ulcer (PU) diseases. The aim of this study was to evaluate the serum concentrations of anti-phosphatidylserine (anti-PS) and anti-cardiolipin (anti-CL) antibodies in H. pylori-infected PU patients, H. pylori-infected asymptomatic (AS) carriers, and a healthy non-infected group and also to determine their correlation with the bacterial virulence factor CagA. A total of 100 H. pylori-infected PU patients (80 patients were positive for anti-CagA antibody and 20 patients were negative for anti-CagA antibody), 65 H. pylori-infected AS carriers (40 subjects were positive for anti-CagA antibody and 25 subjects were negative for anti-CagA antibody) and 30 healthy H. pylori-negative subjects (as a control group) enrolled in the study. Serum samples of participants were tested for the levels of anti-PS and anti-CL antibodies by ELISA. The mean serum levels of anti-PS antibody in the PU group (13.46 +/- 2.90 RU/mL) was significantly higher than that observed in the H. pylori-infected AS group (1.57 +/- 0.38 RU/mL, p < 0.001) and healthy uninfected control group (0.77 +/- 0.32 RU/mL, p < 0.001). No significant difference was observed for the mean serum levels of anti-PS antibody between the AS group and uninfected control group. In the PU group, the mean serum levels of anti-PS antibody was significantly higher in patients with a positive test for anti-CagA antibody (16.46 +/- 3.55 RU/mL) in comparison to patients with a negative test for anti-CagA antibody (2.74 +/- 1.29 RU/mL; p < 0.01). The differences of the mean serum levels of anti-CL antibody were not significant between PU, AS, and control groups. These results showed higher serum levels of anti-PS antibody in patients with PU disease, especially in those infected with the CagA+ strains of H. pylori. Clinical significance of the anti-PS antibody in H. pylori-infected PU patients can be considered in additional follow up studies.

CagA-PositiveHelicobacter pyloriInfection and Reduced Sperm Motility, Vitality, and Normal Morphology

Helicobacter pylori (HP) infection, particularly when caused by strains expressing CagA, may be considered a concomitant cause of male and female reduced fertility. This study explored, in 87 HP-infected males, the relationship between infection by CagA-positive HP strains and sperm parameters. HP infection and CagA status were determined by ELISA and Western blotting; semen analysis was performed following WHO guidelines. The amino acid sequence of human enzymes involved in glycolysis and oxidative metabolism were “blasted” with peptides expressed by HP J99. Thirty-seven patients (42.5%) were seropositive for CagA. Sperm motility (18% versus 32%; P < 0.01), sperm vitality (35% versus 48%; P < 0.01) and the percentage of sperm with normal forms (18% versus 22%; P < 0.05) in the CagA-positive group were significantly reduced versus those in the CagA-negative group. All the considered enzymes showed partial linear homology with HP peptides, but four enzymes aligned with four different segments of the same cag island protein. We hypothesize a relationship between infection by strains expressing CagA and decreased sperm quality. Potentially increased systemic levels of inflammatory cytokines that occur in infection by CagA-positive strains and autoimmune phenomena that involve molecular mimicry could explain the pathogenetic mechanism of alterations observed.

Association of interleukin-1 genetic polymorphism and CagA positive Helicobacter pylori with gastric cancer in Colombia

There is an association of interleukin (IL)1B polymorphism with gastric cancer risk. However systematic reviews of the existing evidence have shown that such association varies across populations with different genetic ancestry. To evaluate the association of IL-1B-511 and IL-1RN polymorphism and Helicobacter pylori IgG antibodies CagA, with gastric cancer in two Colombian cities located in a high risk area for gastric cancer. A case-control study including 46 gastric cancer cases and 99 controls with non-atrophic gastritis from a high risk zone for gastric cancer. Polymorphism genotyping was carried out by polymerase chain reaction (PCR) and IgG CagA status by ELISA. IgG CagA seropositive individuals had an increased gastric cancer risk (odds ratio (OR) = 11.56; 95% confidence intervals (CI) 2.62-50.91 in Tunja and OR = 19.66, 95%CI 0.98-395 in Bogotá). IL-1B-511TT carriers in Tunja had increased risk of gastric cancer (OR = 11.31; 95%CI 1.20-106.54)), while IL-1RN*2 alelle carriers in Bogotá showed an inverse association with gastric cancer risk (OR = 0.03; 95%CI 0.01-0.65). This study adds evidence to the positive association of Helicobacter pylori CagA positive strains with non-cardial gastric cancer etiology. There is a possible heterogeneity in the association of IL-1B gene polymorphism with cancer, in populations of similar ethnic background and settled in the same risk area.

Asociación de los polimorfismos IL-1B-511 e IL-1RN y Helicobacter pylori CagA positivo con cáncer gástrico en una zona de riesgo alto en Colombia

There is an association of interleukin (IL)1B polymorphism with gastric cancer risk. However systematic reviews of the existing evidence have shown that such association varies across populations with different genetic ancestry.To evaluate the association of IL-1B-511 and IL-1RN polymorphism and Helicobacter pylori IgG antibodies CagA, with gastric cancer in two Colombian cities located in a high risk area for gastric cancer.A case-control study including 46 gastric cancer cases and 99 controls with non-atrophic gastritis from a high risk zone for gastric cancer. Polymorphism genotyping was carried out by polymerase chain reaction (PCR) and IgG CagA status by ELISA.IgG CagA seropositive individuals had an increased gastric cancer risk (odds ratio (OR) = 11.56; 95% confidence intervals (CI) 2.62-50.91 in Tunja and OR = 19.66, 95%CI 0.98-395 in Bogotá). IL-1B-511TT carriers in Tunja had increased risk of gastric cancer (OR = 11.31; 95%CI 1.20-106.54)), while IL-1RN*2 alelle carriers in Bogotá showed an inverse association with gastric cancer risk (OR = 0.03; 95%CI 0.01-0.65).This study adds evidence to the positive association of Helicobacter pylori CagA positive strains with non-cardial gastric cancer etiology. There is a possible heterogeneity in the association of IL-1B gene polymorphism with cancer, in populations of similar ethnic background and settled in the same risk area.

EPIYA motif patterns among Cuban Helicobacter pylori CagA positive strains.

It is known that polymorphisms in C-terminal region of CagA influence gastric disease development on Helicobacter pylori infection. Additionally, the geographic distribution of these polymorphisms has been associated with the appearance of more severe gastroduodenal pathologies. Objective. To determine the CagA phosphorylation motifs pattern (EPIYA pattern) in Cuban H. pylori isolates, and to study its association with patient´s pathologies. DNAs from 95 H. pylori cagA-positive strains were used to amplify the 3´ variable region of cagA gene by PCR using two different strategies. Additionally, new primers were designed to identify either Western or Eastern CagAEPIYA motiftype by PCR. To confirm the PCR results, PCR products from 14 representative isolates were purified and sequenced. The distribution of the EPIYA motif found was: 2 AB (2.1 %), 1 AC (1.1 %), 1 BC (1.1 %), 70 ABC (73.6 %), 19 ABCC (20 %), and 2 ABCCC (2.1 %). Sequencing analysis confirmed the PCR classification in the 14 studied strains and showed three strains with unusual nucleotide sequences, not reported before. Distribution of the EPIYA-ABC pattern was equivalent in all pathologies (78.9 % in gastric ulcer, 72.5 % in duodenal ulcer and 72.2 % in non-ulcer dyspepsia). The PCR results using the new primers confirmed that all studied strains carried the Western CagA type. No specific EPIYA motif was associated with peptic ulcer. This is the first report that shows EPIYA motif distribution in H. pylori isolates from the Caribbean region.

EPIYA motif patterns among Cuban Helicobacter pylori CagA positive strains

Introduction. It is known that polymorphisms in C-terminal region of CagA influence gastric disease development on Helicobacter pylori infection. Additionally, the geographic distribution of these polymorphisms has been associated with the appearance of more severe gastroduodenal pathologies.Objective. To determine the CagA phosphorylation motifs pattern (EPIYA pattern) in Cuban H. pylori isolates, and to study its association with patient’s pathologies. Materials and methods. DNAs from 95 H. pylori cagA-positive strains were used to amplify the 3’ variable region of cagA gene by PCR using two different strategies. Additionally, new primers were designed to identify either Western or Eastern CagA EPIYA motif type by PCR. To confirm the PCR results, PCR products from 14 representative isolates were purified and sequencedResults. The distribution of the EPIYA motif found was: 2 AB (2.1 %), 1 AC (1.1 %), 1 BC (1.1 %), 70 ABC (73.6 %), 19 ABCC (20 %), and 2 ABCCC (2.1 %). Sequencing analysis confirmed the PCR classification in the 14 studied strains and showed three strains with unusual nucleotide sequences, not reported before. Distribution of the EPIYA-ABC pattern was equivalent in all pathologies (78.9 % in gastric ulcer, 72.5 % in duodenal ulcer and 72.2 % in non-ulcer dyspepsia).Conclusion. The PCR results using the new primers confirmed that all studied strains carried the Western CagA type. No specific EPIYA motif was associated with peptic ulcer. This is the first report that shows EPIYA motif distribution in H. pylori isolates from the Caribbean region.