Identification of potential diagnostic and vaccine candidates of Helicobacter pylori by "proteome" technologies

There is great interest in characterizing the proteins of the gastric pathogen, Helicobacter pylori, especially those proteins to which humans respond immunologically. Such proteins have potential importance in diagnosis and vaccine development.

Two-dimensional gel electrophoresis in combination with Western blotting was used to separate and identify potential antigens of Helicobacter pylori strain Z-170. Proteins found to be reactive with pooled sera from 14 infected patients were individually digested in situ with endoproteinase Lys-C, and the resulting fragments were analyzed by matrix assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF MS).

Over 20 proteins were reactive in Western blots with pooled sera from 14 infected patients. The mass spectral data was compared with predictions from the H. pylori genome DNA sequence. Each of the 20 proteins was readily identified.

We propose that this "proteome" approach for identification of previously unknown proteins will be useful in examining regulation of H. pylori gene expression and protein localization in the development of improved serologic tests to detect and monitor H. pylori infection. This approach will also be useful for identifying potential targets for antimicrobial or vaccine development for H. pylori and other pathogens whose genomes have been sequenced.