论文部分内容阅读
Genetic immunity is a new promising approach for the development of novel tuberculosis vaccines.In this study,it is shown that DNA vaccines expressing the fusion protein of antigen 8513(Ag85B)and antigenic target antigen MPT83 call induce high levels of specific IgG2a antibody subtype in the mice，the ratio of antibody subtypes IgG2a tO IgG1 changes 4weeks after immunization，and IgG1 is gradually shifted to the main antibody subtype．DNA vaccines also elicit cellular immunity as shown by specific spleen lymphocytes proliferation tO Ag85B or MPT83 protein and the production ofhigh levels of IFN-g and IL-2,which is similar to that elicited by BCG.Vaccination of mice with DNA vaccines expressing the fusion protein Ag85B-MPT83 results in a significant level of protection against the subsequent highdose challenge with virulent Mycobacterium tuberculosis(MTB)H37Rv．The reducing degree of myeobaeterial loads in the organ of mice immunized with recombinant plasmid is more than that of BCG through the analysis of result,we may conclude that the protective effect provided by DNA vaccine expressing the AgS5B-MPT83 fusion protein is much more effective than that afforded by the classical BCG