DNA starvation/stationary phase protection protein of Helicobacter pylori as a potential immunodominant antigen for infection detection.

Abstract

Application of chicken egg yolk immunoglobulin Y (IgY) for Helicobacter pylori (H.pylori, HP) has gained much interest in recent years. Comparing with for treatment, IgY may be more advantageous when used for H.pylori detection. Nine strains of H.pylori with different genetic backgrounds were inactivated and used to immunize hens, respectively, for the preparation of polyclonal anti-H.pylori immunoglobulin Y (anti-HP IgY). The proteins of H.pylori with reactivity to anti-HP IgY were detected by Western Blot. The five protein bands that can be well recognized by anti-HP IgY of each group, and were prevalent in all nine strains were excised from SDS-PAGE gel, digested and identified by Nano-HPLC-MS/MS analysis. The potential of these identified proteins as antigen detection targets was then assessed by sequence analysis. Anti-HP IgY derived from each group of specific strain immunized hens can recognize self-strain and non-self-strain antigens well. Five immunodominant antigens were identified as chaperonin GroEL, flagellin A, urease subunit alpha, peroxiredoxin and DNA starvation/stationary phase protection protein. Sequences analysis showed that both peroxiredoxin and DNA starvation/stationary phase protection protein were present in all 1000 strains of H.pylori queried, and the amino acid sequences were highly conserved. The highest sequence consistency between the DNA starvation/stationary phase protection protein of H.pylori and non-Helicobacter organisms was 52.59%, and the consistent sites were scattered and there was no continuous long fragment consensus sequence. DNA starvation/stationary phase protection protein was identified as an immunodominant antigen of H.pylori and sequence analysis indicated that it could serve as a potential antigen target for the diagnosis of H.pylori infection.