Investigation Of CTLA-4 Nb16 Nanobody Enhancing Tumor-specific CD8~+ T Cells Responses In The Treatment Of Liver Cancer

Background:In order to get a better resistance effect to liver cancer,we used CTLA-4 Nb16 to enhance the efficiency of the tumor-specific T cells which had been induced by high integration DC/Hep G2 cells fusion cells(DC/Hep G2-FC).Objective:To investigate an important negative costimulate molecule CTLA-4 blocking-up by CTLA-4 Nb16 in the process of the activation of T cells,preventing the inhibition of T cell activation by using CTLA-4 in the process of CTL killing activation and eliminating its immunosuppressive function,so as to further promote the antitumor effect of tumor-specific CTL in the adoptive treatment of liver cancer in NOD SCID mice.Methods:DC/Hep G2-FC were generated by fusing Hep G2 cells and human peripheral blood-drived DCs,CTLA-4 Nb16 enhanced the anti-tumor effect of T cells induced by DC/Hep G2-FC.In vitro,flow cytometry was used to detect the proliferation of autologous T lymphocytes that was stimulated by DC/Hep G2-FC@CTLA-4 Nb16.ELISPOT was used to count the IFN-γautologous T cells under the stimulation of DC/Hep G2-FC@CTLA-4 Nb16.The efficiency of tumor-specific CTLs induced by DC/Hep G2-FC@CTLA-4 Nb16 against Hep G2 cells and MCF7 cells.The effects of DC/Hep G2-FC@CTLA-4Nb16 inducing tumor-specific CTLs has been evaluated in vivo for adoptive therapy of liver cancer in NOD SCID mice.Results:CTLA-4 Nb16 promote DC/Hep G2-FC increased the proliferation of CD8~+T cells in vitro and number of T cells secreting IFN-γwas also increased with the stimulation of DC/Hep G2-FC@CTLA-4 Nb16.Tumor-specific CD8~+T cells which was induced by DC/Hep G2-FC@CTLA-4 Nb16 are effectively against tumor cells in tumor tissues.Tumor-specific CD8~+T cells that was induced by DC/Hep G2-FC@CTLA-4 Nb16 inhibited tumor cell proliferation and promoted tumor cell apoptosis in tumor tissues.Adoptive therapy based on the tumor-specific CTLs which was induced by DC/Hep G2-FC@CTLA-4 Nb16 significantly inhibited the tumor growth and prolonged the survival of NOD SCID mice with liver cancer.Conclusion:Tumor-specific CTLs which was activated by DC/Hep G2-FC@CTLA-4 Nb16 are highly effective for the treatment of liver cancer,which provide a novel and promising approach for adoptive therapy of liver cancer.