宋内痢疾菌无毒株S7表达霍乱弧菌O抗原及霍乱毒素B亚单位工程菌的构建

CONSTRUCTION OF SHIGELLA SONNEI VACCINE STRAIN EXPRESSING VIBRIO CHOLERAE O ANTIGEN AND CHOLERA TOXIN B SUBUNIT WITH AN ATTENUATED STRAIN OF SHIGELLA SONNEI(S7)

以宋内氏痢疾菌无毒株S7作为受体,将含有编码霍乱弧菌O抗原及霍乱毒素B亚单位基因的质粒转移入其中,构建成重组菌株S7COB。质粒电泳图谱显示重组株中存在被转移的外源质粒。重组株的生化特性和毒力表型与受体相同。菌体凝集和全菌体酶联免疫吸附试验(ELISA)证明在重组株的菌体表面同时表达了霍乱弧菌和宋内氏痢疾菌的O抗原。GM1-ELISA表明该重组株能在细胞内表达霍乱毒素B亚单位。以5亿、10亿的重组株免疫LIBP品系小鼠,免疫小鼠对宋内氏毒株S63攻击的保护率为70％～100％,对霍乱弧菌毒株569B攻击的保护率为30％～54％。

An attenuated strain of Shigella sonnei named S7 was used as a bacterial vaccine vector. As the vector,S7 was transformed with a recombinant plasmid which carried genes encoding V. cholerae O antigen and cholera toxin B sub-unit,and the recombinant vaccine strain S7COB was constructed. The biochemical and virulent characteristics of the strain S7COB were similar to those of the vector. The result of bacterial agglutination test and whole cell ELISA showed that the strain S7COB expressed O antigen of both V. cholerae and 5. sonnei simultaneously on the cell surface. GMl-ELISA indicated that this strain could express specific cholera toxin B subunit within cells. The efficacy of the strain was demonstrated in the mouse challenge model. Vaccination with three doses of 5. 0 X 108 or 1. 0 X 109 of S7COB protected approximately 70%-100% for mice challenged with the virulent 5. sonnei strain S63,and 30%-54% with the virulent V. cholerae strain 569B.