| Recently, With the development of molecular biology, there were some new comprehension of the reasons and the mechanisms of the hepatocarcinoma, the basic reasons were the activating of the carcino-gene and the revulasion of the anticarcino-gene relation to the hepatocarcinoma. on the basis there were rapid development of multiple methods of genetherapy which included carcino-gene, anticarcino gene. self-killing-gene,multiple-resisting-gene,cell-factor gene,etc. Because of the exact curative effect and the good using prospect, the gene therapy of the costimulating molecular were being valued. though its history was very shortly and it has been the emphasis of studing for the carcinoma gene therapy. When the normal cells were effected by the carcinogen, it would transform and become the carcino cells with the development of carcinogen and enviroment. There were large changes on the construction, biostructure and metabolism of the carcino cells. the changing carbohydrate protein would be the new antigen of the carcino cells which included TSA and TAA. TSA only lay the surface of the specific carcino cells but there were no in the normal cells and other carcino cells, TAA could be found not only in the carcinocells but also in the nomal cells or other carcinocells, it hasn't the specificity but the changing of quantity. Not only the activate immunity but also the adoptive immunity was used in the therapy of carcinoma. it would encounter the activating and multipling of the T cell. The CTL cell was the dominant ones, thus the CTL cell wouldn't act unless it previously has been actived by the specific antigen and the actived CTL cell could kill and dissolve the carcinocells with the same antigen and its action was limited by the MHC I antigen. so it only attacked the carcino cells with the same MHCI antigen. IL-2 could euhance the action. The tumor-specfic antigen was-not only the self anigen but also the new antigen. Its immunocompetence was so low that it had to be helped by the other cells. in the acting specific CTL cells. The B cell's affect was being valued. the integrating of the CD28 in the surface of T cell and the B7 in the surface of B cell was the second signal of activating specfic CTL cell and the integrating could stimulate the T cell to compose the cell factors ,so as the IL-2,TNF etc. According to the double signals theory. The carcino cell was the first signal, if there was the second signal of costimulating molecular. The anti carcinoma immunity would be attained and it could explain the effect of immunosurveillance for the carcino cells. When the host cells transf ormed to be the carcino cells with the attacking of the carcinogen. it would express the B7 molecular and induced the anti carcino immunity. On the contrary the carcino cells which couldn't express B7 Would succeed in escaping of the immunosurveillance. The study indicated many kinds of carcino cells couldn't express the B7 molecular. if there was IL-2, The carcino cells transfected by B7 could take the place of the APC and CD4 cell and periodictly stimulate the CTL cells which could be cultivated for the long period of time and it's activating could enforced with the period So the specific CTL cells could be attained with the carcino cells line stablely expressing B7, it had the very good perspectives in the adoptive immuniy therapy. According to the previous study, there were many institutes which had developed the study of the immunal therapy of the carcinoma. their basic imagination was enforcing the expressing of the B7 in the carcinocell with the transfection of gene. Now there have been many cells line which could express B7 molecular except of the hepatocarcinoma. The previous methods of transfecting gene was using the virus as vector. it would encounter the value of virus and the packing cells. Now the liposome was adopted as the vector to transfect the B7 gene into the smmc7721 cells and the B7+ smmc7721 cells were found. The methods had many advantages of the high efficiency and th... |
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