Rapid Communication
Copyright ©2006 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Nov 21, 2006; 12(43): 7042-7046
Published online Nov 21, 2006. doi: 10.3748/wjg.v12.i43.7042
Construction of an oral recombinant DNA vaccine from H pylori neutrophil activating protein and its immunogenicity
Bo Sun, Zhao-Shen Li, Zhen-Xing Tu, Guo-Ming Xu, Yi-Qi Du
Bo Sun, Zhao-Shen Li, Zhen-Xing Tu, Guo-Ming Xu, Yi-Qi Du, Department of Gastroenterology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
Author contributions: All authors contributed equally to the work.
Supported by the National Natural Science Foundation of China, No. 30170427
Correspondence to: Yi-Qi Du, Department of Gastroenterology, Changhai Hospital, Second Military Medical University, 174 Changhai Road, Shanghai 200433, China. duyiqi@hotmail.com
Telephone: +86-21-25074770
Received: July 15, 2006
Revised: July 25, 2006
Accepted: August 11, 2006
Published online: November 21, 2006
Abstract

AIM: To construct a live attenuated Salmonella typhimurium (S. typhimurium) strain harboring the H pylori neutrophil activating protein (HP-NAP) gene as an oral recombinant DNA vaccine, and to evaluate its immunogenicity.

METHODS: By genetic engineering methods, the genomic DNA of H pylori was extracted as a template. The total length of the HP-NAP gene was amplified by polymerase chain reaction (PCR) and cloned into pBT vector for sequencing and BLAST analysis, then subcloned into a eukaryotic expression vector pIRES followed by PCR identification and restriction enzyme digestion. The identified recombinant plasmid pIRES-NAP was transfected into COS-7 cells for target fusion protein expression, and its antigenicity was detected by Western blotting. Then the recombinant plasmid was transformed into a live attenuated S. typhimurium strain SL7207 as an oral vaccine strain, and its immunogenicity was evaluated with animal experiments.

RESULTS: A 435 bp product was cloned using high homology with HP-NAP gene in GenBank (more than 98%). With identification by PCR and restriction enzyme digestion, a recombinant eukaryotic expression plasmid pIRES-NAP containing the HP-NAP gene of H pylori was successfully constructed. The expressed target protein had a specific reaction with H pylorii whole cell antibody and showed a single strip result detected by Western blotting. Oral immunization of mice with recombinant DNA vaccine strain SL7207 (pIRES-NAP) also induced a specific immune response.

CONCLUSION: The successful construction of HP-NAP oral DNA vaccine with good immunogenicity may help to further investigate its immunoprotection effects and develop vaccine against H pylori infection.

Keywords: H pylori; Neutrophil activating protein; DNA vaccine