scholarly journals Identification of B-Cell Epitopes of HspA from Helicobacter pylori and Detection of Epitope Antibody Profiles in Naturally Infected Persons

Vaccines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 65
Author(s):  
Xin Zhang ◽  
Shuli Sang ◽  
Qing Guan ◽  
Haoxia Tao ◽  
Yanchun Wang ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Heat Shock ◽  
B Cell ◽  
Protein A ◽  
Peptide Fragments ◽  
Nickel Ion ◽  
B Cell Epitopes ◽  
E Coli ◽  
Important Target ◽  
H Pylori

Helicobacter pylori (H. pylori), heat-shock protein A (HspA), is a bacterial heat-shock chaperone that serves as a nickel ion scavenging protein. Ni2+ is an important co-factor required for the maturation and enzymatic activity of H. pylori urease and [NiFe] hydrogenase, both of which are key virulence factors for pathogen survival and colonization. HspA is an important target molecule for the diagnosis, treatment, and immune prevention of H. pylori. In this work, HspA was truncated into five fragments to determine the location of an antigen immunodominant peptide. A series of overlapping, truncated 11-amino-acid peptides in immunodominant peptide fragments were synthesized chemically and screened by ELISA. The immunogenicity and antigenicity of the screened epitope peptides were verified by ELISA, Western blot, and lymphocyte proliferation tests. Two novel B-cell epitopes were identified, covering amino acids 2–31 of HspA, which are HP11 (2–12; KFQPLGERVLV) and HP19 (18–28; ENKTSSGIIIP). The antiserum obtained from HP11-KLH and HP19-KLH immunized mice can bind to naive HspA in H. pylori SS2000, rHspA expressed in E. coli, and the corresponding GST fusion peptide. Among HspA seropositive persons, the seropositive rates of HP11 and HP19 were 21.4% and 33.3%, respectively. Both of the B-cell epitopes of HspA are highly conserved epitopes with good antigenicity and immunogenicity.

scholarly journals Helicobacter pylori Heat Shock Protein A: Serologic Responses and Genetic Diversity

1999 ◽  
Vol 6 (3) ◽  
pp. 377-382 ◽  
Author(s):  
Enders K. W. Ng ◽  
Stuart A. Thompson ◽  
Guillermo I. Pérez-Pérez ◽  
Imad Kansau ◽  
Arie van der Ende ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Helicobacter Pylori ◽  
Amino Acid ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Sequence Variation ◽  
Protein A ◽  
Nucleotide Sequences ◽  
Serological Response ◽  
H Pylori

ABSTRACT Helicobacter pylori synthesizes an unusual GroES homolog, heat shock protein A (HspA). The present study was aimed at an assessment of the serological response to HspA in a group of Chinese patients with defined gastroduodenal pathologies and determination of whether diversity is present in the nucleotide sequences encoding HspA in isolates from these patients. Serum samples collected from 154 patients who had an upper gastrointestinal pathology and the presence of H. pylori defined by biopsy were tested for an immunoglobulin G (IgG) serologic response to H. pylori HspA by an enzyme linked immunosorbant assay. HspA-encoding nucleotide sequences in H. pylori isolates from 14 patients (7 seropositive and 7 seronegative for HspA) were analyzed by PCR and direct sequencing of the PCR products. The sequencing results were compared to those of 48 isolates from other parts of the world. Of the 154 known H. pylori-positive patients, 54 (35.1%) were seropositive for HspA. The A domain (GroES homology) of HspA was highly conserved in the 14 isolates tested. Although the B domain (metal-binding site unique to H. pylori) resembled that in the known major variant, particular amino acid substitutions allowed definition of an HspA variant associated with isolates from East Asia. There were no associations between patient characteristics and HspA seropositivity or amino acid sequences. We confirmed in this study that the clinical outcomes of H. pylori infection are not related to HspA antigenicity or to sequence variation. However, B-domain sequence variation may be a marker for the study of the genetic diversity of H. pylori strains of different geographic origins.

scholarly journals Embedding of exogenous B cell epitopes on the surface of UreB structure generates a broadly reactive antibody response against Helicobacter pylori

2021 ◽  
Author(s):  
Junfei Ma ◽  
Shuying Wang ◽  
Qianyu Ji ◽  
Jingxuan Qiu ◽  
Qing Liu
Keyword(s):  
Helicobacter Pylori ◽  
Antibody Response ◽  
B Cell ◽  
Neutralizing Antibodies ◽  
Alternative Therapy ◽  
Chimeric Protein ◽  
B Cell Epitopes ◽  
Vaccine Antigens ◽  
H Pylori ◽  
Reactive Antibody

AbstractSince Helicobacter pylori (H. pylori) resistance to antibiotic regimens is increased, vaccination is becoming an increasingly important alternative therapy to control H. pylori infection. UreB, FlaA, AlpB, SabA, and HpaA proteins of H. pylori were previously proved to be used as candidate vaccine antigens. Here, we developed an engineered antigen based on a recombinant chimeric protein containing a structural scaffold from UreB and B cell epitopes from FlaA, AlpB, SabA, and HpaA. The multi-epitope chimeric antigen, named MECU, could generate a broadly reactive antibody response including antigen-specific antibodies and neutralizing antibodies against H. pylori urease and adhesins. Moreover, therapeutic immunization with MECU could reduce H. pylori colonization in the stomach and protect the stomach in BALB/c mice. This study not only provides a promising immunotherapy to control H. pylori infection, but also offers a reference for antigen engineering against other pathogens.

scholarly journals Effects ofHelicobacter pyloriand Heat Shock Protein 70 on the Proliferation of Human Gastric Epithelial Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Liping Tao ◽  
Hai Zou ◽  
Zhimin Huang
Keyword(s):  
Helicobacter Pylori ◽  
Heat Shock ◽  
Epithelial Cells ◽  
Heat Shock Protein ◽  
Mtt Assay ◽  
Heat Shock Protein 70 ◽  
Hsp70 Expression ◽  
Gastric Epithelial Cells ◽  
Ags Cells ◽  
H Pylori

Infection ofHelicobacter pylori (H. pylori)changed the proliferation of gastric epithelial cells and decreased the expression of heat shock protein 70 (HSP70). However, the effects ofH. pylorion the proliferation of gastric epithelial cells and the roles of HSP70 during the progress need further investigation.Objective.To investigate the effects ofHelicobacter pylori (H. pylori)and heat shock protein 70 (HSP70) on the proliferation of human gastric epithelial cells.Methods. H. pyloriand a human gastric epithelial cell line (AGS) were cocultured. The proliferation of AGS cells was quantitated by an MTT assay, and the expression of HSP70 in AGS cells was detected by Western blotting. HSP70 expression in AGS cells was silenced by small interfering RNA (siRNA) to investigate the role of HSP70. ThesiRNA-treated AGS cells were cocultured withH. pyloriand cell proliferation was measured by an MTT assay.Results.The proliferation of AGS cells was accelerated by coculturing withH. pylorifor 4 and 8 h, but was suppressed at 24 and 48 h. HSP70 expression was decreased in AGS cells infected byH. pylorifor 48 h. The proliferation in HSP70-silenced AGS cells was inhibited after coculturing withH. pylorifor 24 and 48 h compared with the control group.Conclusions.Coculture ofH. pylorialtered the proliferation of gastric epithelial cells and decreased HSP70 expression. HSP70 knockdown supplemented the inhibitory effect ofH. pylorion proliferation of epithelial cells. These results indicate that the effects ofH. pylorion the proliferation of gastric epithelial cells at least partially depend on the decreased expression of HSP70 induced by the bacterium.

scholarly journals MALT lymphoma: epidemiology, clinical diagnosis and treatment

2018 ◽  
Vol 11 (3) ◽  
pp. 187-193 ◽  
Author(s):  
Petruta Violeta Filip ◽  
◽  
Denisa Cuciureanu ◽  
Laura Sorina Diaconu ◽  
Ana Maria Vladareanu ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
B Cell ◽  
Malt Lymphoma ◽  
Cell Lymphoma ◽  
Gastric Lymphoma ◽  
Eradication Therapy ◽  
B Cell Lymphoma ◽  
Gastric Malt Lymphoma ◽  
H Pylori

Primary gastric lymphoma (PGL) represents a rare pathology, which can be easily misdiagnosed because of unspecific symptoms of the digestive tract. Histologically, PGL can vary from indolent marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) to aggressive diffuse large B-cell lymphoma (DLBCL). During the years, clinical trials revealed the important role of Helicobacter pylori (H. pylori) in the pathogenesis of gastric MALT lymphoma. Infection with Helicobacter pylori is an influential promoter of gastric lymphomagenesis initiation. Long-term studies revealed that eradication therapy could regress gastric lymphomas.

scholarly journals Development of an Internal Control for Evaluation and Standardization of a Quantitative PCR Assay for Detection of Helicobacter pylori in Drinking Water

2007 ◽  
Vol 73 (22) ◽  
pp. 7380-7387 ◽  
Author(s):  
Keya Sen ◽  
Nancy A. Schable ◽  
Dennis J. Lye
Keyword(s):  
Helicobacter Pylori ◽  
Drinking Water ◽  
Quantitative Pcr ◽  
Water Samples ◽  
Sodium Thiosulfate ◽  
Qpcr Assay ◽  
E Coli ◽  
H Pylori ◽  
Labeled Probe ◽  
Treated Drinking Water

ABSTRACT Due to metabolic and morphological changes that can prevent Helicobacter pylori cells in water from growing on conventional media, an H. pylori-specific TaqMan quantitative PCR (qPCR) assay was developed that uses a 6-carboxyfluorescein-labeled probe (A. E. McDaniels, L. Wymer, C. Rankin, and R. Haugland, Water Res. 39:4808-4816, 2005). However, proper internal controls are needed to provide an accurate estimate of low numbers of H. pylori in drinking water. In this study, the 135-bp amplicon described by McDaniels et al. was modified at the probe binding region, using PCR mutagenesis. The fragment was incorporated into a single-copy plasmid to serve as a PCR-positive control and cloned into Escherichia coli to serve as a matrix spike. It was shown to have a detection limit of five copies, using a VIC dye-labeled probe. A DNA extraction kit was optimized that allowed sampling of an entire liter of water. Water samples spiked with the recombinant E. coli cells were shown to behave like H. pylori cells in the qPCR assay. The recombinant E. coli cells were optimized to be used at 10 cells/liter of water, where they were shown not to compete with 5 to 3,000 cells of H. pylori in a duplex qPCR assay. Four treated drinking water samples spiked with H. pylori (100 cells) demonstrated similar cycle threshold values if the chlorine disinfectant was first neutralized by sodium thiosulfate.

scholarly journals Immunogenicity in poultry of in silico predicted - continuous B-cell epitopes from influenza virus H5N1

2013 ◽  
Vol 16 (1) ◽  
pp. 23-33
Author(s):  
Kim Thi Hong Tran ◽  
Thuoc Linh Tran
Keyword(s):  
B Cell ◽  
Influenza A ◽  
H5n1 Virus ◽  
Glutathione S Transferase ◽  
B Cell Epitopes ◽  
E Coli ◽  
Bioinformatic Tools ◽  
Hemagglutination Inhibition Test ◽  
H5n1 Influenza ◽  
Influenza H5n1

In order to develop vaccine with stable efficiency against easily transforming virus such as influenza H5N1 virus, bioinformatic tools were used to predict conserved epitopes from viral antigens to be used as materials for the development of polyvalent vaccine against this virus. Using this approach, we have successfully predicted B-cell continuous and discontinuous epitopes on conserved domains of HA and NA antigens from H5N1 influenza A virus. To confirm the immunogenicity of these epitopes, genetic manipulating techniques have been employed, to prepare the recombinant epitopes in E. coli as a fusion form with H:1,2 flagellin antigen from Salmonella Typhimurium and with glutathione S-transferase. These recombinant antigens have been collected, purified and used for animal immunizing. This study shows the results in specific immunogenicity of recombinant B-cell epitopes continuous in chickens. Using HI test (Hemagglutination Inhibition Test), we could successfully prove that the antiserum from both of chicken groups immunized with GST-H:1,2-HeBc and GST-H:1,2-NeBc had specific antibodies could inhibit the agglutination of antigens derived from an influenza H5N1 virus strain isolated from infected chickens in Vietnam. The HI titer of anti-GST-H:1,2-NeBc antibodies was 113,00, that is 1,19 times higher than the HI titer of anti-GST-H:1,2-HeBc antibodies (95,00), while the HI titer of antibodies from chickens immunized with commercial inactivated vaccine H5N1 reached 291,58.

scholarly journals Antibacterial Activity of Geraniol in Combination with Standard Antibiotics against Staphylococcus aureus, Escherichia coli and Helicobacter pylori

2018 ◽  
Vol 13 (7) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Subrat Kumar Bhattamisra ◽  
Chew Hui Kuean ◽  
Lee Boon Chieh ◽  
Vivian Lee Yean Yan ◽  
Chin Koh Lee ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Helicobacter Pylori ◽  
Antibacterial Activity ◽  
Synergistic Effect ◽  
Inhibitory Concentration ◽  
Therapeutic Potential ◽  
E Coli ◽  
Checkerboard Assay ◽  
H Pylori

The antibacterial activity of geraniol and its effect in combination with ampicillin, amoxicillin and clarithromycin against Staphylococcus aureus, Escherichia coli and Helicobacter pylori was tested. The minimum inhibitory concentrations (MICs) and combinatory effects of geraniol against the bacteria were assessed by using the modified broth microdilution and checkerboard assay, respectively. The combinatory effect is expressed as fractional inhibitory concentration index (FICI). The MIC of geraniol against S. aureus, E. coli and H. pylori was found to be 11200, 5600, and 7325 μg/mL, respectively. A significant synergistic effect was observed with geraniol and ampicillin against S. aureus with FICI in the range 0.19 to 0.32. Geraniol and ampicillin exhibited a partial synergistic effect against E. coli. A similar effect was observed with geraniol and clarithromycin against S. aureus. A partial synergistic effect was observed with clarithromycin and geraniol against H. pylori with the FICI value in the range 0.86 to 0.89. An additive effect was observed with geraniol and amoxicillin combination against H. pylori. However, the amoxicillin and clarithromycin dose was reduced by thirty-two fold when combined with geraniol against H. pylori. The anti- H. pylori effect of geraniol with clarithromycin and amoxicillin could be of potential interest in the treatment of H. pylori infection and associated ulcers in humans. Further, geraniol, in combination with other antibiotics, has substantial therapeutic potential against S. aureus and E.coli infection.

Protection against Helicobacter pylori infection in mice by intragastric vaccination with H. pylori antigens is achieved using a non-toxic mutant of E. coli heat-labile enterotoxin (LT) as adjuvant

Vaccine ◽  
1998 ◽  
Vol 16 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Marta Marchetti ◽  
Michela Rossi ◽  
Valentina Giannelli ◽  
Marzia M Giuliani ◽  
Mariagrazia Pizza ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Helicobacter Pylori Infection ◽  
E Coli ◽  
Heat Labile ◽  
H Pylori

scholarly journals Bacterial killing in gastric juice – effect of pH and pepsin on Escherichia coli and Helicobacter pylori

2006 ◽  
Vol 55 (9) ◽  
pp. 1265-1270 ◽  
Author(s):  
H. Zhu ◽  
C. A. Hart ◽  
D. Sales ◽  
N. B. Roberts
Keyword(s):  
Escherichia Coli ◽  
Helicobacter Pylori ◽  
Gastric Juice ◽  
Bacterial Killing ◽  
E Coli ◽  
Test Organisms ◽  
H Pylori ◽  
Ph Range ◽  
K 12 ◽  
Rough Mutant

The susceptibility of Escherichia coli and Helicobacter pylori to pH and the effect of pepsin-mediated proteolysis were investigated. This was to establish the relative importance of their bacterial killing properties in gastric juice. Solutions in the pH range 1.5–7.4 with or without pig pepsin A were used, together with seven gastric juice samples obtained from patients undergoing routine gastric collection. Escherichia coli C690 (a capsulate strain), E. coli K-12 (a rough mutant) and Helicobacter pylori E5 were selected as the test organisms. Suspensions of bacteria (1×106 E. coli ml−1 and 1×108 H. pylori ml−1) were pre-incubated with test solutions at 37 °C for up to 2 h, and then cultured to establish the effect on subsequent growth. Survival of bacteria was diminished at pHs of less than 3.5, whereas killing required a pH of less than 2.5. Pre-incubation with pig pepsin at 0.5, 1.0 and 2.0 mg ml−1 at pH 3.5 reduced viable counts by 100 % for E. coli 690 and E. coli K-12 after 100 min incubation. With H. pylori, the viable counts decreased to 50 % of the control after 20 min incubation in 1 mg pepsin ml−1 at pH 2.5, 3.0 and 3.5. The gastric juices showed bactericidal activity at pH 3.5, and the rate of killing was juice dependent, with complete death of E. coli 690 occurring between 5 and 40 min post-incubation. Thus, killing of E. coli and H. pylori occurs optimally at pHs of less than 2.5. At pH 3.5, little effect is observed, whereas addition of pepsin alone or in gastric juice causes a marked increase in bacterial susceptibility, suggesting an important role for proteolysis in the killing of bacteria.

scholarly journals 16S rRNA Mutations That Confer Tetracycline Resistance in Helicobacter pylori Decrease Drug Binding in Escherichia coli Ribosomes

2005 ◽  
Vol 187 (11) ◽  
pp. 3708-3712 ◽  
Author(s):  
Lisa Nonaka ◽  
Sean R. Connell ◽  
Diane E. Taylor
Keyword(s):  
Escherichia Coli ◽  
Helicobacter Pylori ◽  
16S Rrna ◽  
Binding Site ◽  
Tetracycline Resistance ◽  
Drug Binding ◽  
Multicopy Plasmid ◽  
Wild Type ◽  
E Coli ◽  
H Pylori

ABSTRACT Tetracycline resistance in clinical isolates of Helicobacter pylori has been associated with nucleotide substitutions at positions 965 to 967 in the 16S rRNA. We constructed mutants which had different sequences at 965 to 967 in the 16S rRNA gene present on a multicopy plasmid in Escherichia coli strain TA527, in which all seven rrn genes were deleted. The MICs for tetracycline of all mutants having single, double, or triple substitutions at the 965 to 967 region that were previously found in highly resistant H. pylori isolates were higher than that of the mutant exhibiting the wild-type sequence of tetracycline-susceptible H. pylori. The MIC of the mutant with the 965TTC967 triple substitution was 32 times higher than that of the E. coli mutant with the 965AGA967 substitution present in wild-type H. pylori. The ribosomes extracted from the tetracycline-resistant E. coli 965TTC967 variant bound less tetracycline than E. coli with the wild-type H. pylori sequence at this region. The concentration of tetracycline bound to the ribosome was 40% that of the wild type. The results of this study suggest that tetracycline binding to the primary binding site (Tet-1) of the ribosome at positions 965 to 967 is influenced by its sequence patterns, which form the primary binding site for tetracycline.

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