[Antitumor immune responses induced by idiotype-pulsed dendritic cells with cell-penetrating peptide vaccination in vivo].

OBJECTIVE: To confirm the therapeutic effect of dendritic cell (DC) vaccine on treatment for mice with lymphoma and the protective effect of DC vaccine loaded with different antigens on the tumor-bearing BAL B/c mice. METHODS: Firstly, a mouse tumor model was set up by s. c. inoculation of 1 x 10(6)/mouse A20 tumor cells. Then different DC vaccines were injected, respectively, and the tumor size and survival time were observed. Secondly, the immunized mice with DC vaccines were challenged with A20 tumor cells, and observed whether a new tumor occurred in the mice and the time of survival. RESULTS: The tumor of mice immunized with Id-DC vaccines grew slower than the controls (mean time of survival was 40.4 days vs. 33.4 days), but statistically not significantly different. The tumor of mice injected with CPP-Id-DC vaccines grew slower than that injected with Id-DC vaccines and controls, and one of 5 mice got CR and the tumor in another one mouse became stable. The median survival time was 70.8 days during a 90-days observation period. The difference was significant (P<0.01). The mice injected with Id-DC vaccines were challenged with A20 tumor cells showed new tumor occurred at 7 - 12 days, and 1 of the 5 mice survived for 60 days. The mice injected with CPP-Id-DC vaccines had no tumor. CONCLUSION: The DC loaded with CPP-Id was better than that loaded with Id alone in treating B cell lymphoma, and It can enhance their antitumor responses and prolong the survival time of the A20 tumor animal models. The vaccine of DC loaded with CPP-Id can protect mice from A20 tumor cell challenge.