IDENTIFICATION OF POTENTIAL DIAGNOSTIC AND VACCINE CANDIDATES OF HELICOBACTER-PYLORI BY PROTEOME TECHNOLOGIES

Background. There is great interest in characterizing the proteins of the gastric pathogen, Helicobacter pylori, especially those proteins t o which humans respond immunologically. Such proteins have potential i mportance in diagnosis and vaccine development. Methods. Two-dimension al gel electrophoresis in combination with Western blotting was used t o separate and identify potential antigens of Helicobacter pylori stra in Z-170. Proteins found to be reactive with pooled sera from 14 infec ted patients were individually digested in situ with endoproteinase Ly s-C, and the resulting fragments were analyzed by matrix assisted lase r desorption time-of-flight mass spectrometry (MALDI-TOF-MS). Results. Over 20 proteins were reactive in Western blots with pooled sera from 14 infected patients. The mass spectral data was compared with predic tions from the H. pylori genome DNA sequence. Each of the 20 proteins was readily identified. Conclusions. We propose that this ''proteome'' approach for identification of previously unknown proteins will be us eful 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 developmen t for H. pylori and other pathogens whose genomes have been sequenced.