Böhm C, Hanski M L, Gratchev A, Mann B, Moyer M P, Riecken E O, Hanski C
Department of Gastroenterology, University Hospital Benjamin Franklin, Berlin, Germany.
J Immunol Methods. 1998 Aug 1;217(1-2):71-8. doi: 10.1016/s0022-1759(98)00100-8.
Tumor cells from several organs including colon have recently been shown to express Fas ligand (FasL) in vitro and in vivo. The expression, which in some tumours occurs de novo, was suggested to facilitate immune escape of malignant cells by killing tumor-infiltrating lymphocytes via Fas-FasL-induced apoptosis. An argument to support this hypothesis is the detection of tumor cell-induced apoptosis in Jurkat cells (as model T cells) by means of the widely used JAM test. In the present work the validity of this test for the analysis of colon carcinoma cell-mediated apoptosis in Jurkat cells was scrutinized in detail. The presented data show that the JAM test as described previously is prone to false-positive detection of apoptosis, when adherent epithelial cells are used as effectors. Furthermore, three lines of evidence indicated that several FasL+ colon carcinoma cell lines did not induce detectable apoptosis in Jurkat cells in vitro. We conclude that: (1) The JAM test must be modified for testing DNA fragmentation induced through adherent effector cells and (2) FasL+ colon carcinoma cells may be unable to induce apoptosis in vitro.
最近研究表明，包括结肠在内的多个器官的肿瘤细胞在体外和体内均表达Fas配体（FasL）。在一些肿瘤中，这种从头开始发生的表达被认为通过Fas - FasL诱导的凋亡杀死肿瘤浸润淋巴细胞，从而促进恶性细胞的免疫逃逸。支持这一假设的一个论据是，通过广泛使用的JAM试验检测到肿瘤细胞诱导Jurkat细胞（作为模型T细胞）凋亡。在本研究中，详细审查了该试验在分析结肠癌细胞介导的Jurkat细胞凋亡中的有效性。所呈现的数据表明，当使用贴壁上皮细胞作为效应细胞时，先前描述的JAM试验容易出现凋亡的假阳性检测。此外，三条证据表明，几种FasL +结肠癌细胞系在体外并未诱导Jurkat细胞中可检测到的凋亡。我们得出结论：（1）必须对JAM试验进行修改，以检测贴壁效应细胞诱导的DNA片段化；（2）FasL +结肠癌细胞可能无法在体外诱导凋亡。
