荷载肿瘤干细胞抗原的树突状细胞对抗肿瘤免疫反应的影响

Dendritic cells loaded with the cancer stem cells antigen can improve antitumor immune responses

目的 观察荷载肿瘤干细胞抗原的树突状细胞（DC）疫苗对抗肿瘤免疫反应的影响.方法 通过流式细胞分选法筛选肿瘤细胞中乙醛脱氢酶阳性（ALDH＋）细胞;利用无血清培养基中细胞克隆球形成实验和皮下成瘤实验,验证所得ALDH＋细胞是否具有肿瘤干细胞特性;然后通过冻融裂解法制备肿瘤干细胞抗原;通过酶联免疫吸附试验（ELISA）法检测白细胞介素-12（IL-12）分泌量,乳酸脱氢酶（LDH）释放法检测DC诱导细胞毒性T淋巴细胞（CTL）对普通肿瘤细胞及肿瘤干细胞的杀伤作用.结果 Hepa1-6 ALDH＋细胞所占比例为3.27％,B16 ALDH＋细胞所占比例为3.40％;所得ALDH＋细胞具有肿瘤干细胞特性;肿瘤干细胞抗原与阴性对照组比较,可使DC分泌更多IL-12（P ＜0.05）,能诱导针对普通肿瘤细胞更强的CTL杀伤作用（P＜0.05）;肿瘤干细胞抗原与各对照组比较,可以诱导针对肿瘤干细胞更强的CTL杀伤作用（P＜0.05）,尤其效应细胞与靶细胞比值（E∶T）为40∶1时,在Hepa1-6和B16两种细胞株中对肿瘤干细胞杀伤率分别达到（56.5±4.6）％和（60.5±5.5）％.结论 荷载肿瘤干细胞抗原的DC可以促进抗肿瘤免疫反应,诱导针对肿瘤干细胞及肿瘤细胞更强的CTL杀伤作用.

Objective To study the effects of administration of the cancer stem cells （CSC） antigen loaded tumor vaccine in mice on antitumor immune.Methods We identified the acetaldehyde dehydrogenase positive （ALDH ＋） cells by using ALDEFLUOR stem cell identification kit and flow cytometry.Then test whether the ALDH ＋ cells had the characteristics of CSC by tumor clone ball culture experiments and subcutaneous tumor formation experiments.CSC antigens were prepared by repeating freezing and thawing cells.Dendritic cells （DCs） ＆#39; interleukin-12 （IL-12） secretion was evaluated by enzyme linked immunosorbent assay （ELISA）.The cytotoxic lymphocyte （CTL） activity against normal cancer cells and CSC induced by DCs was tested by LDH cytotoxicity assay.Results The proportion of Hepa1-6 ALDH ＋cells is 3.27%,the proportion of B16 ALDH ＋ cells is 3.40%.The ALDH ＋ cells were proved with the characteristics of CSC.DCs loaded with CSC antigen could significantly secret more IL-12.DCs loaded with CSC antigen could induce stronger CTL activity against normal cancer cells than control.DCs loaded with CSC antigen could induce stronger CTL activity against CSC,especially when the E∶T ratio was 40∶1,the kill rates were （56.5 ± 4.6） % and （60.5 ± 5.5） % in two cell lines.Conclusion DCs loaded with CSC antigen could induce more effective antitumor immune effects against CSC.