Exosomes致敏的脐血树突细胞介导的抗K562细胞作用

Anti-K562 cells effect mediated by dendritic cells derived from cord blood pulsed with exosomes.

目的分离K562细胞释放的exosomes，致敏脐血树突细胞（dendritic cell，DCs），观察其对细胞毒性T淋巴细胞（cytotoxic T lymphocytes，CTLs）的激活效应。方法离心超滤和蔗糖密度梯度离心法分离K562细胞释放的exosomes，固相免疫电镜法（SPIEM）制备exosomes的HSP70、ICAM-1及ABL免疫电镜标本。常规方法从脐血单个核细胞诱导DCs并分离T细胞，将K562细胞来源的exosomes冲击或未冲击的DCs与T细胞共培养。MTT比色法检测体外细胞毒活性。结果K562细胞分泌的exosomes为直径50～100nm的膜性微囊。Exosomes致敏的脐血DCs激活CTLs的能力显著高于肿瘤冻融抗原致敏的DCs组，在效靶比为50：1时，两组CTLs对l（562细胞的杀伤率为（68，4％vs35．3％，P〈0．05）。结论K562细胞分泌的exosomes负载脐血DCs后活化CTLs，有抗肿瘤活性。

Objective To observe the activation effect on cytotoxic T lymphocytes （CTLs） by cord blood dendritic cells （DCs） pulsed with exosomes derived from I（,562 cells. Methods Exosomes were purified by ultrafiltration centrifugation and sucrose gradient ultracentrifugation. The expression of HSP70,ICAM - 1 ,ABL were investigated by solid phase immunoelectron microscopic method （SPIEM）. DCs and T cells were prepared from cord blood mononuclear cells by conventional methods. The DCs pulsed with or without K562 - derived exosomes were cultured with T cells. Cytotoxicity was assayed with MTT colorimetric method in vitro. Restuits Transmission electron microscopy revealed that exosomes from K562 cell culture supernatants were 50 to 100 run membrane vesicles. DCs pulsed with exosomes could active auto T lymphocytes and induce specific CTLs activity. The CTLs effects induced by DCs pulsed with thawed tumor antigens were also achieved, hut were less effective than that induced by DCs pulsed with exosomes [E：T=50：1, cytotoxicity （35.3% vs 68.4%, P 〈0.05） ]. Conclusion Cord blood DCs pulsed with exosomes can promote the effect of CTLs against tumor in vitro.