摘要目的 探讨PEP3-KLH负载树突状细胞(DCs)疫苗诱导的特异性抗前列腺癌(PCa)免疫作用.方法 用PEP3-KLH或KLH体外冲击小鼠骨髓来源DCs,构建DCs瘤苗.PEP3-KLH-DC皮下免疫C57BL/6J小鼠3次,每次间隔2周.末次免疫后1周,ELISA法检测小鼠血清IL-2、IL-12、及IFN-γ含量;乳酸脱氢酶(LDH)法检测小鼠脾T细胞、肿瘤浸润淋巴细胞(TILs)特异性细胞毒性T淋巴细胞(CTL)活性;观察不同抗原负载DC疫苗对肿瘤攻击小鼠免疫保护作用,计算存活期肿瘤平均体积和小鼠生存率;流式细胞术(FCM)检测肿瘤局部TILs的CD4+、CD8+T细胞阳性表达百分率.结果 PEP3-KLH-DC免疫可诱导分泌较高水平IFN-γ和IL-12;CTL杀伤肿瘤细胞活性增强,其中TIL细胞毒活性明显增强;FCM检测该组肿瘤局部TILs的CD4+、CD8+T细胞阳性表达率明显高于DC-KLH组和DC+ PBS组(P＜0.01),而对照组之间比较差异无统计学意义(P＞0.05).通过比较肿瘤生长曲线、生存曲线可见PEP3-KLH-DC组小鼠肿瘤体积明显较其它各组小,生存率明显提高(P＜0.01).结论 PEP3-KLH-DC疫苗能有效抑制肿瘤生长,诱导和增强机体抗PCa特异性细胞免疫功能.

abstractsObjective To explore the effects of anti-tumor immunity induced by dendritic cells (DCs) vaccine pulsed with PEP3-KLH (keyhole limpet hemocyanin) on induction of specific immunity against prostate cancers.Methods DCs were propagated from bone marrow of C57BL/6 mice in vitro with granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4).On day 5 of culture, DCs were harvested and incubated with PEP3-KLH or KLH.Then the DC vaccine was inoculated into C57BL/6 mice by subcutaneous injection for three times with an interval of two weeks.One week after the last vaccination, the levels of IL-2, IL-12, and interferon (IFN)-γwere measured with enzyme-linked immunosorbent assay (ELISA) kit.The aforementioned immunized mice with DC vaccines were challenged with transgenic adenocarcinoma of mouse prostate (TRAMP)-C2 tumor cells, the tumor growth curve was drawn, and survival rate was checked and compared.The cytotoxic T lymphocyte (CTL) activity induced by DCs was tested with lactate dehydrogenase (LDH) release method.The percentages of CD3 + , CD4+ ,or CD8 + T cells in tumor-infiltrating lymphocytes (TILs) were determined with flow cytometry.Results PEP3-KLH-DC group stimulated the body and induced higher levels of secreted IL-2, IL-12, and IFN-γ compared to DCs control and KLH-DC groups (P ＜ 0.01).The tumor of mice vaccinated with PEP3-KLHDC grew significantly slower than that injected with DCs or KLH-DC (P ＜0.01).Compared to the others, the survival rate in PEP3-KLH-DC group raised remarkably (P ＜ 0.01).PEP3-KLH-DC group induced more outstanding specific CTL activities of killing tumor cells than DCs control group and KLH-DC group (P ＜ 0.01), and the cytotoxicities of TILs in PEP3-KLH-DC group was significantly enhanced (P ＜0.01).The percentages of CD3 + , CD4 + , or CD8 + T cells in TILs (40.9％, 34.1％) in PEP3-KLH-DC group were significantly higher than those in DC-KLH (27.3％, 5.2％) or DCs (26.2％, 5.1％) group.Conclusions PEP3-KLH-DC vaccine can inhibit effectively tumor growth, enhance long-term survival in mice,intensify the local immunologic function of tumor, and elicit and promote profound specific anti-prostate cancer cellular immune responses.