A Study Of The Immunological Effect Of The DNA Vaccine Encoding Tubercle Antigen 85A With 85B In Tumor-bearing Mice

Objective:To explore the immunological effect of the DNA vaccine encoding Mycobacterium tuberculosis Ag85A with Ag85B in mice with bladder cancer.Methord:Using the mouse bladder cancer cell strain BTT739 cultured in vitro,subcutaneously inject to the left hind limb of the mouse T739 constructed the tumor-bearing model.Fourty eight contruction of the successful T739 tumor-beating mice,using random number table were divided randomly into six groups and subjected to the following treatments respectively:subcutaneously immunized with NS,pcDNA3.1,BCG,pcDNA-Ag85A,pcDNA-Ag85B,and pcDNA-Ag85A+ pcDNA-Ag85B,immune time is seven days,fourteen days,and twenty-one days after tumor bearing,and each immune one time.At the end of seven days after immunization,the mice were sacrificed.Flow cytometry was used to detect the mouse spleen of CD4⁺ and CD8⁺T cell subsets number and percentage and calculate the ratio of the CD4⁺/CD8⁺;Enzyme-linked immunosorbent assay(ELISA)was used to detect the mouse serum interferon(IFN_-γ)secretion level.Dynamic monitoring and recording change in the size of tumors in mice;Weighing after stripping cancer tumor and do tumor tissue psthology detection.Results:1.pcDNA-Ag85A plasmids and pcDNA-Ag85B plasmids were extracted from E.coli JM109.2.CD4⁺ and CD8⁺T cell subsets results:Ag85A and Ag85B DNA vaccine combined immunization group of CD4⁺ and CD8⁺ T cell subsets number and the ratio of CD4⁺/CD8⁺ were significantly higher than the DNA vaccine alone immunization,the difference was significant (p＜0.05),but less than BCG group(p＜0.05).3.The mouse serum IFN_-γsecretion level:Ag85A and Ag85B DNA vaccine combined immunization group of the IFN_-γ,level of the mouse serum were significantly higher than the DNA vaccine alone immunization,the difference was significant(p＜0.05),but less than BCG group(p＜0.05).4.Weighing tumor:Ag85A and Ag85B DNA vaccine combined immunization group of the mouse tumor weight less than the DNA vaccine alone immunization,the difference was significant(p＜0.05),but higher than BCG group(p＜0.05).5.Pathological change in tumor tissue:Ag85A and Ag85B DNA vaccine combined immunization group,the tumor necrosis is obvious,and a large number of inflammatory cells around the tumor and infiltrating the tumor.It is obvious than the DNA vaccine alone immunization.In the BCG group,the tumor necrosis is very obvious,and a large number of inflammatory cells around the tumor and infiltrating the tumor.Conclusion:1.Ag85A and Ag85B DNA vaccine immunization for the treatment of bladder cancer process has obvious immune response,was better than DNA vaccine alone immunization, the two have combined synergies enhance immune function.2.Ag85A and Ag85B DNA vaccine against human bladder tumor immune effects still fail to come up to the level of BCG.