[Establishment of an attenuated salmonella typhimurium vaccine strain SL3261 expressing Hp-NAP gene].
OBJECTIVE
To develop an attenuated salmonella typhimurium vaccine strain SL3261 expressing Helicobacter pylori neutrophile activation protein(Hp-NAP).


METHODS
The Hp-NAP gene was amplified by PCR and was cloned into prokaryotic expression plasmid pTrc99A to construct recombinant plasmid pTrc99A-NAP. After the pTrc99A-NAP was performed successively by PCR, enzyme digestion analysis and sequencing the homology was compared between the cloned Hp-NAP gene and related genes in GenBank. The vaccine strain SL3261 was transformed by pTrc99A-NAP. After cultivation, positive colonies were picked out and the plasmid was amplified by PCR and enzyme digestion analysis again. The expression of Hp-NAP protein in the SL3261 bacteria was proved by SDS-PAGE and thin layer scanning.


RESULTS
Sequencing and homologous analysis showed that the homology between the cloned Hp-NAP gene and related genes in GenBank reached 98% for their nucleotide and deduced amino acid sequences. The expression of Hp-NAP protein could be detected in the culture fluid of SL3261 bacteria. Relative molecular mass (M(r)) of expression product was about 15 000, and expression amount accounted for 37.5% of total bacterial protein.


CONCLUSIONS
An attenuated salmonella typhimurium vaccine strain SL3261 has been established successfully, which lays the foundation for further developing oral HP vaccine.
Jiao
Zhi-Yong
ZY
Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080,China.
Chen
Min-Hu
MH
Zhu
Sen-Lin
SL
Li
Guo-Qing
GQ
Chen
Jie
J
Hu
Pin-Jin
PJ
D001428:Bacterial Vaccines / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D016480:Helicobacter pylori / Q000276:immunology; D012486:Salmonella typhimurium / Q000235:genetics; D014613:Vaccines, Attenuated / Q000235:genetics
D001428:Bacterial Vaccines; D014613:Vaccines, Attenuated