Preliminary Study On New--Type Vaccine Of Brucellosis

Aims: To develop new-type vaccines of brucellosis and to guarantee safe and effective prevention and cure to the brucellosis. Methods: (1) Genetic recombinant technique was used to amplify gene fragments of protective antigens of BCSP31,BCSP39,L7/L12 and fusion genetic fragments of protective antigens of BCSP31-L7/L12,BCSP39-L7/L12 from Br.melitensis, Br.abortus, Br.suis, respectively .They were, cloned into a prokaryotic expression vector pQE30. Inducuction by IPTG was performed to get expressed recombinant proteins and then purified recombinant protein antigens of BCSP31, BCSP39,L7/L12 and BCSP31-L7/L12, BCSP39-L7/L12 were obtained by chromatographic column. (2) BCSP31, BCSP39, L7/L12 gene fragments and BCSP31-L7/L12, BCSP39-L7/L12 fusion genetic fragments of protective antigens of Brucella were amplified, cloned into eukaryotic expression vector PCDNA3, and then transfected into Hela cells respectively. With the existence of G418, the recombinant protein antigens of BCSP31,BCSP39,L7/L12 and BCSP31-L7/L12, BCSP39-L7/L12 were proved to be expressed by narrow blotting. (3) Univalent and bivalent genetic vaccines of brucellosis were prepared using the constructed BCSP31/PCDNA3, BCSP39/pcDNA3, L7/L12/pcDNA3, BCSP31-L7/L12/pcDNA3 and BCSP39-L7/L12/pcDNA3, and univalent and bivalent genectically engineered protein vaccines of brucellosis was prepared using protein antigens of BCSP31, BCSP39,L7/L12, andBCSP31-L7/L12, BCSP39-L7/L12 as well. Balb/c mice were immunized three times and observed response and immune protective effect against the attack of toxic strains of Br.melitensis, Br.abortus and Br.suis were observed. Results: The results of sequencing constructed recombinant plasmids agreed to the designed sequences. Recombinant proteins of BCSP31,BCSP39,L7/L12 and BCSP31-L7/L12, BCSP39-L7/L12 were expressed in both prokaryotic and eukaryotic cells, and then were purified respectively .The purified proteins were proved to have immunological activity. Immunized Balb/c mice using genetic vaccines of new type vaccines of brucellosis produced effective specific antibodies and cellular immune response. Conclusions: New-type vaccines of brucellosis initially proved good immune response effect. Further study of these new-type vaccines of brucellosis is carrying on, and it is hopeful to guarantee safe and effective prevention and cure to the brucellosis. Besides, it will establish a foundation for new-type vaccines of other contagious diseases.