Peters L J
Br J Cancer. 1975 Mar;31(3):293-300. doi: 10.1038/bjc.1975.64.
Experiments were undertaken to test the general validity of the assumption that potentiation of tumour transplantability by sublethal whole body irradiation (WBI) implies some degree of immunological resistance in the intact host. A transplantable carcinoma of spontaneous origin in CBA mice which exhibits a large WBI effect was assayed quantitatively in mice which had been immunologically crippled in terms of allograft acceptance by depletion of thymus derived lymphocytes. The mean number of tumour cells required for 50% successful takes (TD50) in these mice was found to be not significantly different from that in normal controls but highly significantly greater than in WBI mice. On the other hand, in mice which underwent laparotomy immediately before assay, the TD50 was reduced significantly though not to the same extent as in WBI mice. It was concluded that WBI effect was not due to impaired host immunity but possibly to physiological changes resulting from acute stress. The hypothesis that hyperfibrinogenaemia which occurs after both WBI and laparotomy might increase tumour transplantability was rejected because of the lack of correlation between TD50 and fibrinogen levels at different times after each procedure. From this and other work it is apparent that TD50 data, in themselves, give no reliable indication of host immunity.
亚致死性全身照射（WBI）增强肿瘤移植能力意味着完整宿主存在一定程度的免疫抗性。在CBA小鼠中，有一种自发起源的可移植性癌，其表现出较大的WBI效应。在通过耗尽胸腺来源淋巴细胞而在同种异体移植接受方面免疫受损的小鼠中，对这种癌进行了定量测定。发现这些小鼠中50%成功接种所需的肿瘤细胞平均数量（TD50）与正常对照无显著差异，但比WBI小鼠中的TD50高得多。另一方面，在测定前立即接受剖腹手术的小鼠中，TD50虽有显著降低，但未降至与WBI小鼠相同的程度。得出的结论是，WBI效应并非由于宿主免疫受损，而是可能由于急性应激导致的生理变化。由于在每次手术后不同时间TD50与纤维蛋白原水平之间缺乏相关性，因此否定了WBI和剖腹手术后出现的高纤维蛋白原血症可能会增加肿瘤移植能力的假设。从这项研究及其他工作可以明显看出，TD50数据本身并不能可靠地表明宿主免疫情况。
