[Cloning and functional analysis of promoter pagC from attenuated Salmonella typhimurium].
This study describes the cloning and function of promoter pagC (P(pagC)) from Salmonella typhimurium. The expression plasmid containing the in vivo-inducible promoter pagC and HGV-NS3 gene was introduced into the attenuated Salmonella typhimurium SL7207 to investigate the function of P(pagC). The expressed HGV-NS3 protein was detectable by SDS-PAGE and Western blotting in the recombinant bacteria in the presence of low concentration of Mg2+ (<50 mmol/L). When the concentration of Mg2+ reached to 50 mmol/L, the amount of expressed HGV-NS3 was decreased significantly. The recombinant bacteria were multiplied in LB medium containing 50 mmol/L of Mg2+ and used as a DNA vaccine to orally inoculate C57 mice for three times. The results of serum antibodies, T lymphocyte proliferative response and cytotoxic T lymphocyte response of immunized mice showed that the oral vaccine could iuduce strong humoral and cellular immune responses in mice, which indicates that the P(pagC) is a strong in vivo-inducible promoter and can be used in attenuated Salmonella typhimurium to construct an effective oral vaccine.
Wang
Hongwei
H
Department of Microbiology, Second Military Medical University, Shanghai 200433, China. smmuwhu@yahoo.com.cn
Zhao
Ping
P
Zhang
Min
M
Zhu
Shiying
S
Qi
Zhongtian
Z
D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001426:Bacterial Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D011401:Promoter Regions, Genetic; D012480:Salmonella Infections / Q000276:immunology / Q000382:microbiology*; D022562:Salmonella Vaccines / Q000008:administration & dosage / Q000276:immunology; D012486:Salmonella typhimurium / Q000235:genetics* / Q000276:immunology; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D008565:Membrane Proteins; D022562:Salmonella Vaccines; D014613:Vaccines, Attenuated; C066766:pagC protein, Salmonella typhimurium