肿瘤exosome诱导特异性T杀伤细胞的研究

目的检测癌细胞来源的exosome在体外刺激细胞毒性T淋巴细胞(CTL)特异性杀伤癌细胞的能力.方法分离纯化舌鳞癌Tca8113细胞,培养上清液中的exosome,制备癌细胞的冻融抗原(FTA),并把两者负载到从血液分离和培养的树突状细胞(DC)上,测定其诱导的CTL对Tca8113的杀伤活性,以SPCA-1人肺腺癌细胞系和95-D人巨细胞癌为对照组.结果体外FTA和exosome冲击致敏的DC能显著刺激T淋巴细胞增殖,其诱导的CTL对细胞系Tca8113具有显著的杀伤作用,在效靶比为20:1时12 h平均分别为45.19%+4.57%和43.60%+5.66%(P＜0.01);exosome冲击致敏的DC诱导的CTL对SPCA-1人肺腺癌也有明显的杀伤作用(P＜0.05),但FTA冲击致敏的DC诱导的CTL却无此功能.结论肿瘤细胞培养上清液中分离出的exosome,负载到DC上后,可以活化T细胞,使之成为抗原特异性的CTL,具有特异性的杀伤肿瘤细胞的功能,为口腔癌的免疫治疗开拓了新的途径.exosome特异的CTL也可杀死其他肿瘤细胞,说明肿瘤来源的exosome是一种可引起肿瘤消退的共同抗原.

Study of Induction of Tumor Specific Cytotoxic T Lymphocyte by Using Tumor-derived Exosome

Objective To investigate whether the exosomes derived from Tca8113 could induce production of tumor -specific T cells when pulsed onto dendritic cells. Methods Tca8113 cell was cultured with RPIM1640, isolated and purified the tumor-derived exosomes from the culture supematants by ultrafiltration with Millipore centrifual filter devices; frozen and thawed Tca8113 cells to get frozen tumor antigens (FTA). The exosomes and FTA was pulsed onto DC generated from normal human peripheral blood mononuclear cell(PBMC)in vitro. The DC pulsed with FAP or exosomes cocultured with the peripheral blood lymphocytes to transform T cell into specific CTL To observe the killing and wounding activity of CTL, the CTL and Tca8113 cells were mixed at a ratio of 20 to1, SPCA-1 cells and 95-D cells was evaluated as control group. Results The CTL induced by DC pulsed with FAP or exosomes had significant activity killing Tca8113(P<0.01); Moreover the CTL induced by DC pulsed with exosomes could also kill SPCA-1 cells (P<0.05), but the CTL induced by DC pulsed with FTA had not this function. Conclusion Exosomes derived from tumour accumulate in culture supematants. Exosomes are a natural and new source of tumour-rejection antigens, opening up new avenues for immunotherapy against oral cancers. The exosome-specific CTL could kill another kind of tumor, so tumor-derived exosomes may contain shared tumor-rejection antigens.