Williams R M, Germain R N, Benacerraf B
J Natl Cancer Inst. 1975 Mar;54(3):697-708.
As in vitro assay of cell-mediated antitumor immunity based on the inhibition of tumor cell DNA synthesis (IDS) was devised. It was reasoned that both cytolytic and cytostatic antitumor effects could be measured in a quantitative yet generalized manner with this approach. By the use of microculture techniques and simplified methods for the determination of tritiated-thymidine incorporation by all cells in individual cultures, normal and immune effector (E) cell populations were compared in their ability to inhibit the DNA synthesis of a fixed initial number of various target tumor cells. Doubling dilutions of E cells were used to titrate the antitumor effects of normal and immune cells at many E/T (effector to target) ratios. Under conditions of alloimmunization, significant immunologically specific IDS effects could routinely be detected at an E/T ratio of less than 1 or 0.1:1, and under certain conditions at 1:100 or less. Results were highly reproducible with respect to the individual E cell donors, replicate cultures, and repeat experiments. The effects were proportional to visually determined cell destruction and independent of obvious culture artifacts. The IDS method was compared with the 51Cr release technique under various experimental conditions. The results demonstrated that decreases in E/T ratio and/or the addition of excess nonimmune cells to immune effector populations had a similar effect in both assays, which was to decrease the magnitude of the immune cell activity. Addition of excess normal cells reduced the activity of immune cells to a level below that of an equal number of immune cells tested at the same E/T ratio without added nonimmune cells. Both assays detected primarily a T lymphocyte-mediated lytic event when effectors generated by the described alloimmunizations were used. The IDS assay also detected a weak non-T-cell activity in anti-theta plus complement-treated alloimmune spleen. The possibility that this represented antibody-dependent cell-mediated cytotoxicity was raised by the finding that normal spleen ceels plus antitarget antibody had significant activity in the IDS system. The sensitivities of the two methods were compared and the potential of the IDS method was evaluated.
设计了一种基于抑制肿瘤细胞DNA合成（IDS）的细胞介导抗肿瘤免疫的体外测定方法。据推测，通过这种方法可以以定量且通用的方式测量细胞溶解和细胞抑制抗肿瘤作用。通过使用微量培养技术和简化的方法来测定各个培养物中所有细胞掺入氚标记胸腺嘧啶核苷的情况，比较了正常和免疫效应（E）细胞群体抑制固定初始数量的各种靶肿瘤细胞DNA合成的能力。使用E细胞的双倍稀释液以多种E/T（效应细胞与靶细胞）比例滴定正常和免疫细胞的抗肿瘤作用。在同种异体免疫的条件下，通常在E/T比例小于1或0.1:1时可检测到显著的免疫特异性IDS效应，在某些条件下在1:100或更低时也可检测到。就个体E细胞供体、重复培养和重复实验而言，结果具有高度可重复性。这些效应与肉眼确定的细胞破坏成比例，并且与明显的培养假象无关。在各种实验条件下将IDS方法与51Cr释放技术进行了比较。结果表明，在两种测定中，E/T比例的降低和/或向免疫效应细胞群体中添加过量非免疫细胞具有类似的效果，即降低免疫细胞活性的幅度。添加过量正常细胞会将免疫细胞的活性降低到低于在相同E/T比例下测试的相同数量免疫细胞（未添加非免疫细胞）的活性水平。当使用所述同种异体免疫产生的效应细胞时，两种测定主要检测到T淋巴细胞介导的溶解事件。IDS测定还在抗θ加补体处理的同种异体免疫脾中检测到弱的非T细胞活性。发现正常脾细胞加抗靶抗体在IDS系统中具有显著活性，这增加了这代表抗体依赖性细胞介导细胞毒性的可能性。比较了两种方法的敏感性并评估了IDS方法的潜力。
