Anti-Helicobacter pylori antibody succession during gastric carcinogenesis monitored with proteomics and antigen-chip analysis

2014 Fiscal Year Final Research Report

• Project/Area Number: 24590919
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Gastroenterology
• Research Institution: Yamaguchi University
• Principal Investigator: AKADA Junko 山口大学, 医学部, 特別医学研究員 (30346548)
• Co-Investigator(Kenkyū-buntansha): NISHIKAWA Jun 山口大学, 医学部附属病院, 准教授 (00379950) ; OKUDA Masumi 兵庫医科大学, 医学部, 教授 (40531091)
• Co-Investigator(Renkei-kenkyūsha): HIRAYAMA Toshiya 長崎大学, 熱帯医学研究所, 教授 (50050696) ; NAKAMURA Kazuyuki 山口大学, 名誉教授 (90107748) ; NAKAMURA Mikiko 山口大学, 大学研究推進機構, 学術研究員 (20457310)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: Helicobacter pylori / 血清 / 抗H. pylori抗体 / 抗原タンパク質 / CagA / 小児

Outline of Final Research Achievements

This study focused on Japanese child serum antibodies against Helicobacter pylori, a chronically-infected gastric bacterium which causes gastric cancer in adults. Serum samples from 24 children, 22 H. pylori (Hp)-positive and 2 Hp-negative children, were used to catalogue antigenic proteins of a Japanese strain CPY2052 by two-dimensional electrophoresis followed by immunoblot and LC-MS/MS analysis. In total, 24 proteins were identified as candidate antigen proteins. Among these, the major virulence factor, cytotoxin-associated gene A (CagA) protein was the most reactive antigen recognized by all the Hp-positive sera even from children under the age of 3 years. The major antigenic part of CagA was identified in the middle region, and two peptides containing CagA epitopes were identified using a newly developed peptide/protein-combined array chip method. Each of the epitopes was found to contain amino acid residue(s) unique to East Asian CagA.

Free Research Field

感染症、微生物学、生化学、プロテオミクス