Production of anti-Helicobacter pylori urease-specific immunoglobulin in egg yolk using an antigenic epitope of H. pylori urease

Abstract

The potential therapeutic effects of Helicobacter pylori-specific immunoglobulin (IgY-Hp) derived from egg yolk and identification of the immunodominant H. pylori proteins have previously been reported. In this study, the urease epitope that is recognized by IgY-Hp was identified and used as an immunogen to produce urease-specific IgY (IgY-HpU). Epitope regions were mapped and peptides of selected epitope regions were synthesized. The IgY-Hp titre against synthetic peptides was evaluated using ELISA analysis. Hens were immunized with synthetic peptides conjugated with BSA. Urease activity was quantified by measuring the optical density of an indicator dye. Of the five synthetic peptides assayed, a peptide representing 15 amino acid residues of UreB (UB-3; aa 396-410, DNDNFRIKRYLSKYT) was specifically recognized by the IgY-Hp. Immunization of hens with BSA-conjugated UB-3 resulted in the generation of IgY-HpU. IgY-HpU markedly reduced H. pylori urease activity by 80 % as compared to control IgY (IgY-BSA). The availability of the synthetic UreBderived peptide enabled the production of highly specific anti-urease IgY, which had a significant inhibitory effect on H. pylori urease activity. Therefore, specific IgY-HpU produced using the synthetic peptide may be an effective tool against infection by H. pylori.

Anti-Helicobacter pylorieffects of IgY from egg york of immunized hens

“…The activity of IgY in our study was similar to that of H. pylori -specific IgY-Hp that inhibited bacterial growth and urease activity by 40 and 24.6% at 1 mg/mL, and 88 and 84.5% at 10 mg/mL, respectively [35]. In another study, H. pylori urease-specific IgY-HpU also inhibited urease activity by 29.9 and 81.7% at 1 and 10 mg/mL, respectively [36], leading to similar efficacies to IgY in the present study. On the other hand, IgY-HpUc specific for UreC subunit of urease exerted higher inhibitory effects on the growth and urease activity of H. pylori [37].…”

Efficacy of Passive Immunization with IgY Antibodies to a 58-kDaH. pyloriAntigen on Severe Gastritis in BALB/c Mouse Model

“…Although anti-H. pylori whole-cell lysate IgY was strongly reactive to H. pylori proteins, a cross-reactivity exists between anti-H. pylori whole-cell lysate IgY and other bacteria in the human gastrointestinal tract which could decrease the efficacy of IgY-Hp [36] Therefore, selective antigens with high immunocompetence from H. pylori proteins are needed to produce a more specific IgY and also reduce side-effects. [37] Targeting of proteins in the gastric lumen using oral antibody requires that the target antigen of H. pylori be located on the surface of the bacterial body. The immunodominant proteins recognized by IgY against H. pylori whole-cell lysate were reportedly related to the urease, heat shock protein 60, peroxiredoxin and thiol peroxidase of H. pylori.…”

The role of type-specific antibodies in colonization and infection by Helicobacter pylori

“…Recombinant secretory IgA and polymeric/dimeric IgA were more efficient in blocking the urease activity of H. pylori than IgG [26 ]. H. pylori-urease-specific Ig derived from egg yolk was reported to have a significant inhibitory effect on urease activity [27]. Moreover, urease-specific antibodies induced by immunization with a recombinant urease B fused with glutathione S-transferase protein were shown to reduce the enzymatic activity of H. pylori urease and specifically bind to human gastric specimens infected with H. pylori [28 ].…”