Brief Reports
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 14, 2005; 11(14): 2154-2156
Published online Apr 14, 2005. doi: 10.3748/wjg.v11.i14.2154
Systemic immune responses to oral administration of recombinant attenuated Salmonella typhimurium expressing Helicobacter pylori urease in mice
Xiao-Feng Liu, Jia-Lu Hu, Qi-Zheng Quan, Zi-Qin Sun, Yao-Jun Wang, Feng Qi
Xiao-Feng Liu, Qi-Zheng Quan, Zi-Qin Sun, Yao-Jun Wang, Feng Qi, Department of Gastroenterology, General Hospital of Jinan Military Command Area, Jinan 250031, Shandong Province, China
Jia-Lu Hu, Institute of Gastroenterology, Xijing Hospital, Fourth Military Medical University, Xi抋n 710032, Shaanxi Province, China
Author contributions: All authors contributed equally to the work.
Correspondence to: Dr. Xiao-Feng Liu, Department of Gastroenterology, General Hospital of Jinan Military Command Area, Jinan 250031, Shandong Province, China.
Telephone: +86-531-6732012
Received: April 12, 2004
Revised: April 13, 2004
Accepted: May 19, 2004
Published online: April 14, 2005

AIM: To evaluate whether attenuated Salmonella typhimurium producing Helicobacter pylori (H pylori) urease subunit B (UreB) could induce systemic immune responses against H pylori infection.

METHODS: Attenuated S. typhimurium SL3261 was used as a live carrier of plasmid pTC01-UreB, which encodes recombinant H pylori UreB protein. Balb/c mice were given oral immunization with two doses of SL3261/pTC01-UreB at a 3-wk interval. Twelve weeks after oral immunization of mice, serum IgG antibodies were evaluated by ELISA assay. Gamma interferon (IFN-γ) and interleukin 10 (IL-10) in the supernatant of spleen cell culture were also assessed by ELISA.

RESULTS: After oral immunization of mice, serum specific IgG antibodies against UreB in vaccine group were much higher than that in PBS and native Salmonella SL3261 control groups (A450, 0.373±0.100 vs 0.053±0.022, 0.142±0.039, respectively, P<0.01). Moreover, IFN-γ in vaccine group was on average 167.53±29.93 pg/mL, which showed a significant increase vs that of PBS control group (35.68±3.55 pg/mL, P<0.01). There was also a tremendous increase of IL-10 in vaccine group compared to PBS and SL3261 control groups (275.13±27.65 pg/mL vs 56.00±7.15 pg/mL, 68.02±15.03 pg/mL, respectively, P<0.01). In addition, no obvious side effects in mice and no change in gastric inflammation were observed.

CONCLUSION: The multiple oral immunizations with the attenuated S. typhimurium expressing H pylori UreB could induce significant systemic immune responses, suggesting it may be used as oral vaccine against H pylori infection.

Keywords: Helicobacter pylori, Salmonella typhimurium, Vaccine, Systemic immune