Sutherland R M, MacDonald H R, Howell R L
J Natl Cancer Inst. 1977 Jun;58(6):1849-53. doi: 10.1093/jnci/58.6.1849.
Multicellular spheroids of EMT6 mammary sarcoma cells of BALB/c origin were incubated with normal spleen cells or alloimmune spleen cells generated in vitro in mixed leukocyte cultures (MLC). After 24 hours, spheroids were trypsinized and assayed for surviving tumor cells by use of a cloning technique. Under these conditions a 60-80% reduction in clone-forming tumor cells was observed after incubation of spheroids with immune lymphocytes as compared to normal lymphocyte controls. This cytotoxic effect occurred in situ, and alloimmune cells sensitized against unrelated antigens were much less cytotoxic than were specifically sensitized cells. In parallel autoradiographic studies, some immune lymphoid cells that had been labeled with tritiated thymidine during the proliferative phase of the MLC could be demonstrated within spheroids after 24 hours. These results suggested that multicellular spheroids will be a useful in vitro model for more detailed analysis of the factors controlling infiltration in in situ destruction of solid tumor grafts.
将源自BALB/c的EMT6乳腺肉瘤细胞的多细胞球体与正常脾细胞或在混合淋巴细胞培养（MLC）中体外产生的同种免疫脾细胞一起孵育。24小时后，将球体用胰蛋白酶消化，并使用克隆技术检测存活的肿瘤细胞。在这些条件下，与正常淋巴细胞对照相比，球体与免疫淋巴细胞孵育后，观察到克隆形成肿瘤细胞减少了60 - 80%。这种细胞毒性作用发生在原位，针对无关抗原致敏的同种免疫细胞的细胞毒性远低于特异性致敏细胞。在平行的放射自显影研究中，在MLC增殖期用氚标记胸腺嘧啶核苷标记的一些免疫淋巴细胞在24小时后可在球体内被检测到。这些结果表明，多细胞球体将是一种有用的体外模型，用于更详细地分析控制实体瘤移植物原位破坏中浸润的因素。
