Zsófia Gyulai

Genetic Polymorphisms of NOD1 and IL-8, but not Polymorphisms of TLR4 Genes, Are Associated with Helicobacter pylori-Induced Duodenal Ulcer and Gastritis

Background:  Intracellular pathogen receptor NOD1 is involved in the epithelial cell sensing Helicobacter pylori, which results in a considerable interleukin (IL)‐8 production. The aim of this study was to evaluate the relationship between NOD1 and IL‐8 genetic polymorphisms and the development of H. pylori‐induced gastritis and duodenal ulcer (DU), as compared with TLR4 polymorphisms.

Investigation of the Prognostic Value of TNF-α Gene Polymorphism among Patients Treated with Infliximab, and the Effects of Infliximab Therapy on TNF-α Production and Apoptosis

Objectives: Infliximab, a chimeric anti-tumor necrosis factor (TNF) antibody, is highly effective for the treatment of Crohn’s disease (CD) and rheumatoid arthritis (RA). Our experiments focused on RA and CD patients receiving infliximab. Since cytokine production is largely determined by genetic factors, the promoter polymorphisms of TNF-α were examined among these patients. Additionally, the changes caused by infliximab in the TNF-α-producing ability and apoptosis of peripheral blood mononuclear cells (PBMCs) were investigated. Methods: The TNF-α genotypes were analyzed by PCR-RFLP. The in vitro TNF-α production of the PBMCs was detected by flow cytometric analysis. The TNF-α concentration in the supernatant was measured by bioassay. Apoptosis was detected by annexin V-fluorescein isothiocyanate labeling. Results and Conclusions: 8 of the 12 nonresponder patients carried the TNF A allele associated with high TNF-α production. We suggest that the determination of TNF polymorphism may help identify more suitable candidates for infliximab treatment. Although in vitro infliximab treatment for 48 h resulted in significant (44.2 ± 1.17%) apoptosis in PBMCs, in ex vivo samples from RA patients who received infliximab, apoptosis was only 13.3 ± 1.6%. Furthermore, infliximab did not result in irreversible inhibition of the TNF-α-producing ability or in the significant apoptosis of PBMCs.

Polymorphism of the heat-shock protein gene Hsp70-2, but not polymorphisms of the IL-10 and CD14 genes, is associated with the outcome of Crohn's disease

Objective. In Crohns disease (CD) a Th-1 dominant immune reaction is induced, which could be associated with genetic predisposition. Several previous studies have investigated the roles of CD14, heat-shock protein (Hsp)70 and IL-10 gene polymorphisms in the development of the disease. The results are contradictory and inter-racial differences are implicated. Therefore, this phenomenon was evaluated in well-documented Caucasian patients with CD in order to verify the clinical importance of these polymorphisms. Material and methods. The genomic DNA of 133 patients with CD and that of 75 healthy controls were examined. CD was divided into subgroups according to the Vienna classification. An arbitrary classification system based on disease severity was also applied, which was determined according to the therapeutic intervention. The CD14 (−159 C→T) promoter gene polymorphism was investigated by melting-point analysis. The IL-10 (−1082 G→A) and Hsp70-2 (1267 A→G) gene polymorphisms were detected by RFLP (restriction fragment length polymorphism). Results. None of the allele frequencies of the examined polymorphisms differed significantly between the patient and control populations. Neither the CD14 nor the IL-10 polymorphisms exhibited any correlation with the development or with the progression of the disease. With regard to Hsp70-2 gene polymorphism, those patients who carry at least one A allele have a significantly lower probability of the need for surgical intervention. Conclusions. Allele A of the Hsp70-2 gene may be associated with a less severe form of CD, suggesting the clinical value of the genotype assessment. The genetic determination of the defense mechanisms in CD appears to be associated with the polymorphism of the Hsp70-2 gene rather than that of the CD14 or IL-10 genes.

Optimization of DNA immunization against human cytomegalovirus.

The immune responses of mice injected with plasmids VR-gB and VR-gB Delta tm expressing the full-length membrane-anchored, or secreted forms of human cytomegalovirus (HCMV)-glycoprotein B (gB), respectively, and VR-pp65 expressing the HCMV-phosphoprotein 65 (pp65) were analyzed. Pretreatment of mice with the local anesthetic bupivacaine did not enhance antibody production, and IFN-alpha co-expressed with the immunizing plasmids induced a moderate increase in the antibody response. However, antibody response was higher in mice inoculated at three sites in the musculus quadriceps than in mice inoculated at one site with the same dose and in the same muscle. pVR-gB Delta tm induced significantly higher antibody titers than the construct expressing the membrane-anchored form of gB, and priming with pVR-gB Delta tm followed by boosting with the gB subunit resulted in high-titer antibody responses. Immunization with VR-pp65 induced dose-dependent CTL responses in about 50% of the mice at a dose of 50 microg. Co-expression of IFN-alpha did not affect the number of responding mice. These findings might be important for optimization of humoral and cellular immune responses to HCMV after DNA vaccination.

T-251A polymorphism of IL-8 relating to the development of histological gastritis and G-308A polymorphism of TNF-α relating to the development of macroscopic erosion

Objectives Genetic variations of the inflammatory IL-8 and TNF-&agr; genes can influence the outcome of gastric alterations. Our aims were to determine the prevalence and effect of the T-251A functional polymorphism of IL-8 and the G-308A polymorphism of TNF-&agr; in histological and macroscopic gastric diseases related to Helicobacter pylori infection. Methods Genomic DNA was extracted from biopsy samples from patients with gastritis (n=86, H. pylori positive=41), atrophy (n=32, H. pylori positive=13), intestinal metaplasia (IM) (n=43, H. pylori positive=22) and from histologically negative patients (n=57). The samples were divided by macroscopic diagnosis into erosion and negative groups. The T-251A polymorphism was examined with the amplification refractory mutation system method; the G-308A polymorphism was determined by the polymerase chain reaction-restriction fragment length polymorphism method. For statistical evaluation, Fischers exact test was used. Results In the case of T-251A of IL-8, the frequency of the A/A genotype was significantly increased in gastritis (P=0.049) and IM (P=0.038) groups as compared with the histologically negative ones. No relationship was found between macroscopic erosions and H. pylori infection. In the case of G-308A, the G/G genotype frequency was statistically increased in erosions as compared with negative groups (P=0.035). No difference in the distribution of G-308A genotypes in relation to histological alterations and the H. pylori infection was observed. Conclusions The effect of the polymorphism of IL-8 seems to be relevant in the pathogenesis of histological gastritis and IM, and the effect of the polymorphism of TNF-&agr; is relevant in the pathogenesis of macroscopic erosive gastritis.

High Mobility Group Box 1 Protein Induction by Mycobacterium Bovis BCG

High mobility group box 1 protein (HMGB1), a nuclear protein, is a critical cytokine that mediates the response to infection, injury, and inflammation. The aim of our study was to elaborate a reliable in vitro model to investigate whether Mycobacterium bovis BCG is able to induce HMGB1 secretion from the monocytic U-937 cells. Western blot technique was applied for the detection of HMGB1 from supernatants of cells, following induction with Mycobacterium bovis BCG. Densitometric analysis revealed higher concentrations of HMGB1 in cell supernatants stimulated with BCG than in the supernatants of the control, nonstimulated cells. Further quantitation of the secreted HMGB1 was performed by ELISA. The BCG strain resulted in a higher amount of secreted HMGB1 (450 ± 44 ng/mL) than that of LPS (84 ± 12 ng/mL) or Staphylococcus aureus (150 ± 14 ng/mL). BCG and Phorbol −12-myristate −13 acetate (PMA), added together, resulted in the highest HMGB1 secretion (645 ± 125 ng/mL). The translocation of the HMGB1 towards the cytoplasm following infection of cells with BCG was demonstrated by immunofluorescence examinations. Conclusion: Our pilot experiments draw attention to the HMGB1 inducing ability of Mycobacterium bovis. Assesment of the pathophysiological role of this late cytokine in mycobacterial infections demands further in vitro and in vivo examinations.

RAGE Gene Polymorphisms in Patients with Multiple Sclerosis

The pathogenesis of multiple sclerosis (MS), a devastating neuroinflammatory disorder of the central nervous system, has been presumed to involve the possible importance of the receptor for advanced glycation end products (RAGE). The aim of this study was to investigate the relevance of the genetic polymorphisms of RAGE in MS patients. A total of 168 patients with MS were enrolled; 136 healthy blood donors served as controls. The −374 T/A, −479 T/C, and the G82S polymorphisms of RAGE were determined by restriction fragment length polymorphism (RFLP). There was a significant difference in RAGE −374 T/A genotype distribution between the controls and the MS patients. The AA homozygote variants were detected in 8% of the patients with MS, as compared with 19% of healthy controls (OR = 2.75; 95% CI = 1.319−5.733, p = 0.007). No differences were observed between the MS patients and the controls, concerning the frequencies of the −479 T/C and G82S genotypes of the RAGE. Our results revealed an association between the −374 T/A polymorphism of the RAGE promoter and MS. The genetic variant −374 AA (which has previously been shown to exert significant effects on transcriptional activity) can be considered a preventive factor as regards the occurrence of MS. Our findings support the view that RAGE plays a role in the development of MS.

Clinical Importance of Transforming Growth Factor-β but Not of Tumor Necrosis Factor-α Gene Polymorphisms in Patients with the Myelodysplastic Syndrome Belonging to the Refractory Anemia Subtype

Objectives: Tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) are cytokines that play key roles in the myelodysplastic syndrome (MDS). There have been several reports on the presence of genetic polymorphisms in the DNA sequence encoding the leader sequence of the TGF-β1 protein, located in codon 10 in exon 1 and in the –308 promoter region of TNF-α. The objective of this study was to investigate the association between TNF-α and TGF-β1 gene polymorphisms and the susceptibility to MDS and the progression of the disease among patients with MDS belonging to the refractory anemia (RA) subtype. Methods: The diagnosis of MDS (n = 50) was based on the FAB criteria. The TNF-α genotypes were analyzed by PCR-RFLP and the TGF-β genotypes were analyzed using an amplification refractory mutation system. Results and Conclusions: Compared with healthy control subjects, patients with RA showed no significant deviations in genotype or allele frequencies of TNF-α. The TT homozygosity at codon 10 of TGF-β1 was significantly higher among patients with bi- or pancytopenia (severe group) than in the patients with anemia only (mild group; odds ratio = 6.99, p = 0.003). These findings suggest that the TGF-β1 gene polymorphism in codon 10 and the –308 TNF-α gene polymorphism do not predispose to the development of RA, but the TGF-β1 gene polymorphism may affect disease progression.