Simultneous Expression of CS3
Colonization Factor Antigen and Cholera Toxin B Subunit in Salmonella typhi
HAN Zhao-Zhong, RUI Xian-Liang, CAO Yong, YING Tian-Yi, SU
Guo-Fu, ZHANG Zhao-Shan and HUANG Cui-Fen
( Beijing Institute of Biotechnology,Beijing 100071,China )
Abstract A host-plasmid balancing
system was established based on asd gene in an avirulent strain of Salmonella
typhi to express enterotoxigenic E.coli surface antigen CS3 and V.cholerae
toxin subunit B(CTB).The plasmid can be stably maintained in the host and can
express CS3 and CTB in the host cell without any antibiotic selection,although
expression level and growth characteristics of the recombinant strain
expressing either CS3 or CTB are superior to that of the recombinant strain
which expresses both of the antigens.Antibo-dies against CS3 and CTB can be
detected in sera of mice immunized with recombinant bacteria either orally or
subcutaneously,and mice immunized subcutaneously can be protected from
challenging with virulent strain of Salmonella typhi.This work may be
helpful in constructing multivalent recombinant vaccines for prevention of
bacterial diarrhea.
Key Words Vaccine；host-plasmid balancing system；CS3 fimbriae；CTB；Salmonella typhi
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