HIFU治疗后肿瘤抗原对树突状细胞的活化及其抗肿瘤效应

目的：探讨HIFU治疗小鼠H22抑制性肝癌后产生的肿瘤抗原对机体抗肿瘤免疫功能增强的机制。方法：正常小鼠骨髓中提取骨髓细胞，在rmIL-4、rmGM-CSF奈件下培养7d，制备小鼠骨髓树突状细胞，用HIFU治疗小鼠移植性肝癌后产生的肿瘤抗原活化树突状细胞，再用活化后的树突状细胞激活T淋巴细胞为细胞毒性T细胞，用MTT法检测CTL在体外特异性杀伤肿瘤靶细胞的能力。结果：B16肿瘤HSP70-肽复合物组和H22肿瘤HSP70-肽复合物组的脾淋巴细胞的增殖率均高于阴性对照组、H22肿瘤粗提物组和HIFU后H22肿瘤粗提物组，P〈0．001；但两组之间差异无统计学意义，P〉0．05。H22肿瘤HSP70-肽复合物组CTL对H22肿瘤细胞的杀伤率为70．0％，明显高于阴性对照组、H22肿瘤粗提物组和HIFU后H22肿瘤粗提物组（P〈0．001），但对非靶细胞B16肿瘤的杀伤率与上述各组的差异无统计学意义；B16肿瘤HSP70-肽复合物组CTL对B16肿瘤细胞的杀伤率为78．5％，对H22细胞的杀伤率为21．4％，表明CTL对肿瘤细胞的杀伤作用具有特异性。结论：HIFU治疗后坏死肿瘤组织中的HSP70-肽复合物作为肿瘤疫苗，通过活化DC和刺激T淋巴细胞增殖为CTL，发挥特异性抗肿瘤免疫功能。

Anti-tumor immunity induced by activated dendritic cells with tumor antigen from HIFU-treated tumors

OBJECTIVE:To explore the mechenism of tumor antigen which is H22 hepatic carcinoma treated with high intensity focused ultrasound(HIFU) to reinforce the anti-tumor immunity.METHODS: Myelocytes derived from normal mice were cultured with rmIL-4 and rmGM-CSF for 7 days to extract myeloid dendritic cells(DCs),and tumor antigen from HIFU-treated tumors activated DCs and cytotoxic T lymphocytes(CTL) were obtained by stimulating T lymphocytes with activated DCs,and CTL specific cytotoxicity against H22 tumor cells was measured in vitro.RESULTS: Spleen lymphocyte proliferation rates were significantly higher in H22 HSP70-peptide complex group and B16 HSP70-peptide complex group than those in serum group,H22 tumor supernatant group and H22 treated tumor supernatant group,P<0.001;but no significant difference was observed between B16 HSP70-peptide complex group and HSP70-peptide complex group,P>0.05.CTL cytotoxicity against H22 tumor cells was 70.0%,which was significantly higher than those in serum group,H22 tumor supernatant group and H22 treated tumor supernatant group,P<0.001,but no statistical difference was observed in CTL cytotoxicity against B16 tumor cells among these four groups.CTL cytotoxicity against B16 tumor cells was 78.5%,and the cytotoxicity against H22 tumor cells was 21.4% in B16 HSP70-peptide complex group,indicating that CTL cytotoxicity original from HIFU-treated tumor had specific anti-tumor immunity.CONCLUSIONS: HSP70-peptide complex purified from HIFU-treated tumor is a tumor vaccine.It could play an important role in host anti-tumor immunity by activating immature DCs,stimulating T lymphocyte proliferation,and inducing CTL production.