PURPOSE: Helicobacter pylori is a widely distributed gram-negative bacterium that infects the human stomach and duodenum. HpaA is a H. pylori-specific lipoprotein that has been shown to be an effective protective antigen against H. pylori infection. HpaA of H. pylori as a vaccine antigen is fully competent for stimulation of immune responses. The aim of this project is cloning, expression, and purification flagellar sheath adhesion of H. pylori in Escherichia coli host by fast protein liquid chromatography (FPLC) as a vaccination target. MATERIALS AND METHODS: The hpaA gene was inserted into pET28a (+) as cloning and expression vectors respectively. The recombinant plasmid (pET-hpaA) was subjected to sequencing other than polymerase chain reaction (PCR) and digestion analysis. Protein expression was induced by adding 1 mM isopropyl-beta-D-thiogalactoside to cultures of E. coli strain BL21 transformed with pET-hpaA. Protein expression assessed with sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Protein purification of flagellar sheath adhesion was by FPLC. RESULTS: The restriction endonuclease digestion, PCR amplification analysis showed that the hpaA gene of 730 bp was amplified from H. pylori DNA and sequencing analysis of the pET-hpaA confirmed the cloning accuracy and in frame insertion of hpaA fragment. SDS-PAGE analysis showed the expression of an approximately 29,000 Da protein. CONCLUSION: Sequencing results along with SDS-PAGE analysis confirms the expression of recombinant hpaA in the heterologous E. coli BL21. Conclusion A prokaryotic expression system for hpaA gene was successfully constructed. These results indicate that production of a specific recombinant protein is an alternative and potentially more expeditious strategy for development of H. pylori vaccine.
Chromatography, Liquid ; Clone Cells* ; Cloning, Organism* ; Digestion ; DNA ; DNA Restriction Enzymes ; Duodenum ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli* ; Escherichia* ; Helicobacter pylori* ; Helicobacter* ; Humans ; Lipoproteins ; Plasmids ; Polymerase Chain Reaction ; Sodium Dodecyl Sulfate ; Stomach ; Vaccination*

PURPOSE: Staphylococcus aureus is one of the most important causes of nosocomial and community-acquired infections. The increasing incidence of multiple antibiotic-resistant S. aureus strains and the emergence of vancomycin resistant S. aureus strains have placed renewed interest on alternative means of prevention and control of infection. S. aureus produces a variety of virulence factors, so a multi-subunit vaccine will be more successful for preventing S. aureus infections than a mono-subunit vaccine. MATERIALS AND METHODS: We selected three important virulence factors of S. aureus, clumping factor A (ClfA), iron-regulated surface determinant (IsdB), and gamma hemolysin (Hlg) that are potential candidates for vaccine development. We designed synthetic genes encoding the clfA, isdB, and hlg and used bioinformatics tools to predict structure of the synthetic construct and its stabilities. VaxiJen analysis of the protein showed a high antigenicity. Linear and conformational B-cell epitopes were identified. RESULTS: The proteins encoded by these genes were useful as vaccine candidates against S. aureus infections. CONCLUSION: In silico tools are highly suited to study, design, and evaluate vaccine strategies.
Community-Acquired Infections ; Computational Biology ; Computer Simulation* ; Epitopes, B-Lymphocyte ; Genes, Synthetic ; Incidence ; Staphylococcus aureus* ; Vaccines ; Vancomycin ; Virulence Factors

PURPOSE: The common triple therapy for Helicobacter pylori is challenged by the increasing cases of antibiotic resistant infections, raising the need to explore alternative therapies. Oral administration of egg yolk immunoglobulin Y (IgY) has been previously reported as a means of passive immunization therapy for H. pylori infections. In this work, we investigated the inhibitory effect of IgY on the attachment of H. pylori to AGS cell line. MATERIALS AND METHODS: Recombinant OipA was prepared. Hens were immunized with recombinant protein three times. IgY was purified from egg yolks of immunized hens using polyethylene glycol precipitation method. The inhibitory effect of the specific immunoglobulin was evaluated in AGS cell line infected with H. pylori. RESULTS: The presence of recombinant OipA (30 kD) was confirmed via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Immunization of hens was confirmed using enzyme-linked immunosorbent assay. The purified IgY from egg yolks were assessed using SDS-PAGE and confirmed by western blot. CONCLUSION: The results showed that IgY-OipA had inhibitory effect on attachment of H. pylori to AGS cell line and may be utilized as a therapeutic or prophylaxis material.
Administration, Oral ; Blotting, Western ; Cell Line* ; Complementary Therapies ; Egg Yolk ; Electrophoresis, Polyacrylamide Gel ; Enzyme-Linked Immunosorbent Assay ; Helicobacter pylori* ; Helicobacter* ; Immunization ; Immunization, Passive ; Immunoglobulins ; Polyethylene Glycols ; Sodium Dodecyl Sulfate