The association of interleukin-18 promoter polymorphisms and serum levels with duodenal ulcer, and their correlations with bacterial CagA and VacA virulence factors

Polymorphism in the Promoter Region of the IL18 Gene and the Association With Severity on Paracoccidioidomycosis

Paracoccidioidomycosis (PCM) is an important endemic, systemic disease in Latin America caused by Paracoccidioides spp. This mycosis has been associated with high morbidity and sequels, and its clinical manifestations depend on the virulence of the infecting strain, the degree and type of immune response, infected tissues, and intrinsic characteristics of the host. The T helper(Th)1 and Th17/Th22 cells are related to resistance and control of infection, and a Th2/Th9 response is associated with disease susceptibility. In this study, we focused on interleukin(IL)-12p35 (IL12A), IL-18 (IL18), and IFN-γ receptor 1 (IFNGR1) genetic polymorphisms because their respective roles have been described in human PCM. Real-time PCR was employed to analyze IL12A-504 G/T (rs2243115), IL18-607 C/A (rs1946518), and IFNGR1-611 A/G (rs1327474) single nucleotide polymorphisms (SNP). One hundred forty-nine patients with the acute form (AF), multifocal chronic (MC), or unifocal chronic (UC) forms of PCM and 110 non-PCM individuals as a control group were included. In the unconditional logistic regression analysis adjusted by ethnicity and sex, we observed a high risk of the IL18-607 A-allele for both AF [p = 0.015; OR = 3.10 (95% CI: 1.24–7.77)] and MC groups [p = 0.023; OR = 2.61 (95% CI: 1.14–5.96)] when compared with UC. The IL18-607 A-allele associated risk for the AF and MC groups as well as the protective role of the C-allele in UC are possibly linked to higher levels of IL-18 at different periods of the course of the disease. Therefore, a novel role of IL18-607 C/A SNP is shown in the present study, highlighting its importance in the outcome of PCM.

Evaluation of cell-penetrating peptide-peptide nucleic acid effect in the inhibition of cagA in Helicobacter pylori

Helicobacter pylori is the most common cause of chronic infection in human and is associated with gastritis, peptic ulcer disease, and adenocarcinoma of mucosa-associated lymphoid tissue cells. Peptide nucleic acid (PNA) is a synthetic compound, which can inhibit the production of a particular gene. This study aimed to investigate the effect of PNA on inhibiting the expression of cagA. After confirmation of the desired gene by polymerase chain reaction (PCR), the antisense sequence was designed against cagA gene. The minimum inhibitory concentrations of conjugated PNA against H. pylori was determined. The effect of the compound on the expression level of the cagA was investigated in HT29 cell culture using real-time PCR. The results showed 2 and 3 log reduction in bacterial count after 8- and 24-h treatment with 4 and 8 μM of the compound, respectively. The lowest expression level of the cagA gene was observed at a concentration of 8 μM after 6 h. The results of this study showed that cell-penetrating peptide antisense can be employed as effective tools for inhibiting the target gene mRNA for various purposes. Moreover, further research is necessary to assess the potency, safety, and pharmacokinetics of CPP-PNAs for clinical prevention and treatment of infections due to H. pylori.

Expressions of the CagA protein and CagA-signaling molecules predict Helicobacter pylori dependence of early-stage gastric DLBCL

Expression of CagA and CagA-signaling molecules p-SHP2 and p-ERK is associated with HP dependence of gastric DLBCL. CagA is associated with the direct lymphomagenic effect of HP on B cells of HP-dependent gastric DLBCL.

Helicobacter pylori infection: An overview of bacterial virulence factors and pathogenesis

Helicobacter pylori pathogenesis and disease outcomes are mediated by a complex interplay between bacterial virulence factors, host, and environmental factors. After H. pylori enters the host stomach, four steps are critical for bacteria to establish successful colonization, persistent infection, and disease pathogenesis: (1) Survival in the acidic stomach; (2) movement toward epithelium cells by flagella-mediated motility; (3) attachment to host cells by adhesins/receptors interaction; (4) causing tissue damage by toxin release. Over the past 20 years, the understanding of H. pylori pathogenesis has been improved by studies focusing on the host and bacterial factors through epidemiology researches and molecular mechanism investigations. These include studies identifying the roles of novel virulence factors and their association with different disease outcomes, especially the bacterial adhesins, cag pathogenicity island, and vacuolating cytotoxin. Recently, the development of large-scale screening methods, including proteomic, and transcriptomic tools, has been used to determine the complex gene regulatory networks in H. pylori. In addition, a more available complete genomic database of H. pylori strains isolated from patients with different gastrointestinal diseases worldwide is helpful to characterize this bacterium. This review highlights the key findings of H. pylori virulence factors reported over the past 20 years.

Influence of H. pylori CagA Coupled with Alcohol Consumption on Cytokine Profiles in Men

The aim of this study was to evaluate the effect of Helicobacter pylori (H pylori) cytotoxin-associated gene A (CagA) coupled with chronic alcohol ingestion on cytokine profiles.A total of 215 male subjects were divided into the following 4 groups: 130 alcohol H pylori CagA-negative consumers (CagA-) (group A), 50 alcohol H pylori CagA-positive consumers (CagA+) (group B), 24 nonalcohol H pylori CagA-negative consumers (group C), and 11 nonalcohol H pylori CagA-positive consumers (group D). The serum CagA, C-reactive protein (CRP), interleukin (IL)-6, IL-10, E-selectin, adiponectin (ADP), and tumor necrosis factor-α (TNF-α) levels were measured through enzyme-linked immunosorbent assays (ELISAs).After adjusting for age and mean alcohol drinking history, a multivariable linear regression analysis revealed that the mean daily alcohol consumption, IL-6, TNF-α, and ADP levels were significantly increased with increases in the serum CagA concentrations (P = 0.008, P = 0.000, P = 0.000, and P = 0.006, respectively). The serum IL-6 and IL-10 levels of group A were significantly lower than those of group B (all P = 0.000). Furthermore, the serum IL-6 and IL-10 levels of groups A and C were significantly lower than those of group D (all P = 0.000), and the serum IL-6 and IL-10 levels of group C were significantly lower than those of group B (all P = 0.000). The serum ADP and E-selectin levels of groups B and D were significantly higher than those of group A (P = 0.000). The serum ADP levels of group B were significantly higher than those of group C (P = 0.000), and the serum ADP and E-selectin levels of group C were significantly lower than those of group D (P = 0.000 and P = 0.005, respectively). Finally, the serum TNF-α levels of groups B, C, and D were significantly higher than those of group A (all P = 0.000), and the serum TNF-α levels of group C were significantly higher than those of group D (P = 0.005).In conclusion, H pylori CagA may result in significantly higher levels of several inflammatory markers in both alcohol consumers and nonalcohol consumers. However, chronic alcohol ingestion coupled with H pylori CagA positivity does not result in significant changes in cytokine profiles.

Association between interleukin-18 gene polymorphism and Helicobacter pylori infection in the Korean population

Interleukin-18 (IL-18) is a pleiotropic, pro-inflammatory cytokine that is capable of promoting the Th1 response. A predominant Th1 response induces chronic and persistent inflammatory changes in the gastric mucosa in response to Helicobacter pylori (H. pylori) infection. The aim of this study was to investigate the potential association between IL-18 gene polymorphisms and susceptibility to H. pylori infection in the Korean population. A total of 678 subjects who underwent a routine health check-up were enrolled. The IL-18 gene polymorphisms at positions −656, −607, −137, +113, and +127 were genotyped. H. pylori positivity was demonstrated in 456 subjects (67.3%). The allele frequencies of IL-18 gene polymorphisms at position −137 (rs187238) were different based on the status of H. pylori infection (G vs. C, adjusted OR 0.64 CI: 0.47–0.87, P = 0.005). The results indicate that the genetic variants in the IL-18 gene may be associated with susceptibility to H. pylori infection in the Korean population, suggesting that IL-18 plays a role in the pathogenesis of H. pylori-associated diseases. However, this finding requires further replication and validation.

Effect of H. pylori Infection on Cytokine Profiles and Oxidative Balance in Subjects with Chronic Alcohol Ingestion

Different amounts of ingested alcohol can have distinct effects on the human body. However, there is limited research on chronic alcohol consumption with Helicobacter pylori infection. We sought to investigate the relationship between the cytokine profile, oxidative balance and H. pylori infection in subjects with chronic alcohol consumption. A total of 142 subjects were divided into three groups: 59 subjects with chronic alcohol ingestion and H. pylori infection (group A); 53 subjects with chronic alcohol ingestion without H. pylori infection (group B); and 30 control subjects (group C). The serum levels of CagA, interleukin (IL)-10, E-selectin, TNF-α, malondialdehyde (MDA) and superoxide dismutase (SOD) activity were measured by enzyme-linked immunosorbent assay (ELISA). We found that the ages and serum H. pylori CagA levels among the three groups, as well as both the mean drinking age and the mean daily alcohol consumption between groups A and B, were matched and comparable. Comparing the BMIs among the three groups, the BMI differences were found to be statistically significant (F=3.921, P<0.05). Compared with group C, the BMIs in groups A and B were significantly higher (P<0.001 and P<0.01, respectively); however, the BMI differences between group A and group B were not statistically significant (P>0.05). Additionally, no differences in the serum CagA levels were found in comparisons among the groups (all P>0.05). The serum IL-10 and E-selectin levels in group A were significantly lower than those in group B (serum IL-10: P<0.05; E-selectin: P<0.05). The serum IL-10 in group A was significantly higher than that in group C (P<0.01); the serum E-selectin levels in group A did not significantly differ compared with those in group C (P>0.05). Furthermore, the serum IL-10 and E-selectin levels in group B were significantly higher than those in group C (serum IL-10: P<0.001; E-selectin: P<0.05); however, the serum TNF-α levels did not differ among groups (all P>0.05). Although the serum levels of MDA and SOD in groups A and B were slightly lower than those in group C, there were no significant differences among groups (all P>0.05). In conclusion, we believe that H. pylori infection might cause a significant inhibition of certain cytokine profiles in subjects with chronic alcohol ingestion. Moreover, chronically ingested alcohol may exert an adjusted inflammatory effect, but there was no association between H. pylori infection, chronic alcohol consumption and oxidative balance.

Helicobacter pylori-an infectious risk factor for atherosclerosis?

Accumulating evidence implicates Helicobacter pylori (H. pylori) infection in the pathogenesis of certain diseases localized outside the stomach, particularly those characterized by persistent and low-grade systematic inflammation. Recently, the role of H. pylori infection in the development of atherosclerosis and its clinical complications has received attention. Atherosclerosis is a high-cost disease, and acute events resulting from this condition rank first among morbidity and mortality statistics in most industrialized countries. Atherosclerosis is a multifactorial disorder, and traditional risk factors explain only 50% of its etiology. Therefore, identifying new risk factors for atherosclerosis is necessary. Serological studies indicate that chronic H. pylori infection, especially that with more virulent strains, may predispose patients to the onset of atherosclerosis and related adverse clinical events, and PCR studies have detected H. pylori DNA in atherosclerotic plaques, although this finding remains controversial. If this association were to be confirmed, its importance to public health would be substantial, as the eradication of H. pylori is more straightforward and less costly than the long-term treatment of other risk factors. This review investigates the potential relationship between H. pylori infection and atherosclerosis from both epidemiological and pathogenic perspectives and characterizes the potential mechanisms underlying this correlation.

Immunity, inflammation, and vaccines for Helicobacter pylori

Helicobacter pylori colonizes mucosa, activates Toll-like and Nod-like receptors, and usually elicits a gastric T-helper 1/17 (Th1/Th17) type of immune response. Among several bacterial factors, the secreted peptidyl prolyl cis, trans-isomerase of H. pylori represents a key factor driving Th17 inflammation. A complex and fascinating balance between H. pylori and host factors takes part in the gastric niche and is responsible for the chronicity of the infection. Novel insights into the innate and adaptive responses against H. pylori, dealing with gastric epithelial cells, cytokines, and immune evasion have been elucidated over the past year and are discussed for the development of an effective vaccine.