Antitumor Protective Immunity Induced by Dendritic Cells Based Vaccine in Humanised Nude Mice Model

Objective 　To explore antitumor protective immunity induced by dendritic cells based vaccine in humanised nude mice model. Methods 　Immature DCs generated from peripheral blood mononuclear cells were transfected with gastric carcinoma total RNA in vitro. A humanized nude mice model was established by intraperitoneal (i. p. ) injection of human peripheral blood T-lymphocytes ( HuPBTL ) . The mice were randomly divided into DCRNA group, DCs group and PBS group of 5 mice each. The mice were immunized s. c. with DC_RNA or DCs and PBS, respectively, twice, at weekly intervals. Three days after the last immunization mice were challenged s. c. with BGC-823 cells. The CD4 ⁺ and CD8 ⁺ T cell subpopulations of human T-lymphocytes from peripheral blood of humanised nude mice were detected by flow cytometry and graft versus host disease ( GVHD) were observed. Tumor growth, tumor volume, tumor weight and tumor inhibition rate were observed. Production of cytokine IL-12 and IFN-γ were detected by ELISA kit . Results 　The CD4 ⁺ and CD8 ⁺ T cells subpopulations of human T2lymphocytes from peripheral blood of humanised nude mice were found in each group. GV HD was not occurrence in each group. Overall tumor volume in DCRNA group mice was significantly lower than those of DCs group and PBS group ( P < 0. 05) . Tumor weight in DCRNA group was significantly lighter than those of DCs group and PBS group ( P = 0. 0452, P = 0. 0004), but this difference was not statistically significant between DCs group and PBS group ( P = 0. 0618) . Inhibition tumor rate for DCRNA group (53. 7 %) was higher than that for DCs group (25. 1 %) ( P < 0. 05) . Production of cytokine IL-12 and IFN-γ in DC_RNA group were significantly increased relatived to DCs group and PBS group ( P < 0. 05, P < 0. 01) . Conclusion 　A humanised nude mouse model was successfully established by i. p. injection of HuPBTL. DCs based vaccine is capable of inducing enhanced antitumor protective immunity in vivo.