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Copyright ©2008 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Aug 14, 2008; 14(30): 4816-4822
Published online Aug 14, 2008. doi: 10.3748/wjg.14.4816
Diversity of Helicobacter pylori isolates in expression of antigens and induction of antibodies
Ren-Xian Tang, Dong-Jiao Luo, Ai-Hua Sun, Jie Yan
Ren-Xian Tang, Department of Medical Microbiology and Parasitology, Xuzhou Medical College, Xuzhou 221009, Jiangsu Province, China
Dong-Jiao Luo, Qianjiang College, Hangzhou Normal University, Hangzhou 310018, Zhejiang Province, China
Ai-Hua Sun, Faculty of Basic Medicine, Zhejiang Medical College, Hangzhou 310053, Zhejiang Province, China
Jie Yan, Department of Medical Microbiology and Parasitology, College of Medicine, Zhejiang University, Hangzhou 310053, Zhejiang Province, China
Author contributions: Tang RX and Yan J designed the research; Tang RX and Luo DJ performed the research; Tang RX, Luo DJ, Sun AH and Yan J analyzed the data; Tang RX and Sun AH contributed equally to this work; Tang RX wrote the paper.
Supported by The Natural Science Foundation of Zhejiang Province, No. Y207696
Correspondence to: Jie Yan, Department of Medical Microbiology and Parasitology, College of Medicine, Zhejiang University, Hangzhou 310053, Zhejiang Province, China. med_bp@zju.edu.cn
Telephone: +86-571-88208297 Fax: 86-571-88208194
Received: April 11, 2008
Revised: July 14, 2008
Accepted: July 21, 2008
Published online: August 14, 2008
Abstract

AIM: To obtain evidence for selection of antigens used in genetically engineered vaccine against Helicobacter pylori (H pylori).

METHODS: Enzyme linked immunoabsorbent assay (ELISA) was established on the basis of recombinant protein antigens rUreB, rHpaA, rVacA, rCagA1, rNapA, rFlaA and rFlaB of H pylori to detect expression rates of the antigens in bacterial isolates as well as positive rates of the antibodies in sera from H pylori-infected patients. PCR was applied to the detection of carrying rates of the genes encoding antigens in the isolates.

RESULTS: The outputs of rUreB, rHpaA, rVacA, rCagA1, rNapA, rFlaA and rFlaB were approximately 35%, 32%, 15%, 23%, 56%, 25% and 20% of the total bacterial proteins, respectively. One hundred and fifty-one strains of H pylori were isolated from 347 biopsy specimens of chronic gastritis, peptic ulcer or gastric adenocarcinoma, with a positive rate of 43.5%. All of the isolates expressed UreB, HpaA, FlaA and FlaB while 52.3%, 92.1% and 93.4% of the isolates expressed VacA, CagA and NapA, respectively. In the sera of 151 H pylori-infected patients, the positive rates of IgG antibodies against UreB, HpaA, VacA, CagA, NapA, FlaA and FlaB were 100%, 87.4%, 43%, 71.5%, 89.4%, 84.8% and 79.5%, respectively. Furthermore, the expression frequencies of VacA and NapA were found to be relative to the severity of gastric diseases (P = 0.016 and P < 0.0001, respectively).

CONCLUSION: UreB antigen is the top option of developing genetically engineered vaccine against H pylori followed by NapA or HpaA.

Keywords: Helicobacter pylori; Major protein antigens; Expression frequency; Antibody levels