Objective： To investigate the antitumor effect of dendritic cell （DC） modified by gp96-peptide complexes both in vitro and in vivo. Methods：Gp96-peptide complexes were acquired from H22 liver cancer cells in mice. DC were cultured from bone marrow cells and modified by gp96-peptide complexes. Spleen lymphocytes of mice were activated by modified DC and the cytotoxicity were detected by ^51Cr release method. Modified DC, gp96-peptide complexes and inactivated H22 cells were injected into mice bearing H22 liver cancer cells to observe the levels of IL-10, IFN-y in serum and the alteration of proportions of CD8^＋-IFNy^＋ and CD8^＋-IL-10^＋ cells, CD4^＋-IFNy^＋ and CD4^＋-IL-10^＋ cells. Results： DC modified by gp96-peptide complexes can activate spleen lymphocyte and the latter can specifically kill H22 cells but not Ehrilich ascites carcinoma cells. Modified DC can improve the host＇s antitumor immune response and the proportions of Thl cells, inhibiting tumor growth. Conclusion： Gp96-peptide complexes can activate DC effectively, making DC a good vaccine.
Objective： To improve DC-based tumor vaccination, we studied whether dendritic ceils （DCs） which cocultured with H22 liver cancer cells-derived heat shock protein （HSP） glycoprotein 96 （gp96） affect the T cell-activating potential in vitro and the induction of tumor immunity in vivo. Methods： Maturation of murine bone marrow-derived DC was induced by GM-CSF plus IL-4, which mimiced the immunostimulatory effect of DC. Cocultured DC and gp96-peptide complexes were used to vaccine H22 liver cancer cells of mice. Using murine models we compared the immunogenecity of DC modified by gp96-peptides complexes derived from murine liver cancer cells alone or inactive tumor cells. To verify the specificity of the vaccine, in vitro assays were executed. Serum cytokine levels were quantified to explore the supposed pathway of DC modified by gp96 peptide complexes and its effect on antitumor immune response. Results： DC modified by gp96-peptide complexes can activate spleen lymphocyte and the latter can specifically kill H22 cells but not Ehrilich ascites carcinoma cells. Modified DC can induce potent tumor-antigenspecific immune response, augment the proliferation of Thl cells, and inhibit tumor growth. Conclusion： In this study, we have developed a novel DC-mediated tumor vaccine by combing the gp96 antigenic peptides complexes and inducing immune response against specific tumor cells, gp96 can be identified as a potent DC activator.
Objective： Heat shock protein （HSP） has the promiscuous abilities to chaperone and present a broad repertoire of tumor antigens to antigen presenting cells including DCs. In this report, we analyzed the modulation of immature DC by lISP 96 （gp96）. Method： Murine bone marro6-derived DC was induced by GM-CSF plus IL-4, which aped the immunostimulatory effects of DC. Cocultured DC and gp96-peptide complexes （gp96-PC） or inactivated H22 cells, the expression of MHC class Ⅱ , CD40, CD80 was quantified by flow cytometry. The concentration of IL-12 and TNF- in culture supematants were determined by ELISA. C1 release assay was used to test specific cytotoxic T cell. Results： Our study demonstrated that the extent of DC maturation induced by gp96-PC, which was reflected in surface density of costimulatory and MHC Ⅱmolecules, was correlated with the secretion of IL-12 and with the T cellactivating potential in vitro. Conclusion： Heat shock protein 96 could be isolated and purified from H22 cells and could induce maturation of dendritic cell. Our findings might be relevance to the use of DC vaccine in therapy of human tumors.
Chunxia CaoWei YangYonglie ChuQingguang LiuLiang YuCheng＇ en Pan
