Katsanis E, Bausero M A, Xu H, Orchard P J, Xu Z, McIvor R S, Brian A A, Blazar B R
Department of Pediatrics, University of Minnesota, Minneapolis 55455.
Cancer Immunol Immunother. 1994 Feb;38(2):135-41. doi: 10.1007/BF01526209.
We determined the expression of intercellular adhesion molecules (ICAM) on neuro-2a cells in order to evaluate whether they were involved in cytolysis of murine neuroblastoma. Fluorescence-activated cell sorting analysis revealed that the control neomycin-resistance-gene-transduced line (neuro-2a/LN) had poor expression of ICAM-1 (mean channel fluorescence, MCF = 3.7). An ICAM-1-positive transfectant of neuro-2a (neuro-2a/ICAM-1+) (MCF = 64.3) was generated to evaluate directly the role of this adhesion molecule in cytolysis. Neuro-2a/ICAM-1+ was more sensitive to LAK killing (69.7% at an effector-to-target ratio of 100:1) compared to neuro-2a/LN (48.6%) (P < 0.001). Blocking of neuro-2a/LN and neuro-2a/ICAM-1+ lysis with anti-ICAM-1 monoclonal antibodies (mAbs) did not account for all the LFA-1-dependent killing. These data indicate that even in neuro-2a/ICAM-1+ cells, other LFA-1 ligands participated in the effector-target interaction. Therefore, we examined these cell lines for ICAM-2 expression. Both neuro-2a/LN and neuro-2a/ICAM-1+ lines expressed ICAM-2 (MCF = 16.4 and 16.5). ICAM-2 accounted for the majority of the LFA-1-dependent killing in the ICAM-1-negative target, neuro-2a/LN, while ICAM-1 played a primary role in the cytolysis of the ICAM-1+ transfectant. Inhibition of lysis in the presence of anti-ICAM-1 and ICAM-2 mAbs was comparable to that seen with the addition of anti-LFA-1 mAb, indicating that other LFA-1 ligands were not involved in this system. ICAM-1 expression was associated with decreased in vivo tumorigenicity, mice inoculated with neuro-2a/ICAM-1+ cells had a significantly longer survival compared to those receiving neuro-2a/LN cells (median survival time 35.5 versus 24.5 days) (P < 0.001). It is important to note that ICAM-1 transfection of murine neuroblastoma did not alter its metastatic potential. We conclude that transfection of mouse neuroblastoma with ICAM-1 increases its sensitivity to in vitro lysis and reduces its in vivo tumorigenicity. In ICAM-1-negative murine neuroblastoma cells, ICAM-2 plays a primary role in cell-mediated lysis.
我们测定了神经母细胞瘤细胞（Neuro-2a）上细胞间黏附分子（ICAM）的表达，以评估它们是否参与小鼠神经母细胞瘤的细胞溶解过程。荧光激活细胞分选分析显示，对照新霉素抗性基因转导细胞系（Neuro-2a/LN）ICAM-1表达水平较低（平均通道荧光强度，MCF = 3.7）。我们构建了Neuro-2a的ICAM-1阳性转染细胞系（Neuro-2a/ICAM-1+）（MCF = 64.3），以直接评估这种黏附分子在细胞溶解中的作用。与Neuro-2a/LN（48.6%）相比，Neuro-2a/ICAM-1+对LAK杀伤更敏感（效应细胞与靶细胞比例为100:1时，杀伤率为69.7%）（P < 0.001）。用抗ICAM-1单克隆抗体（mAb）阻断Neuro-2a/LN和Neuro-2a/ICAM-1+的细胞溶解作用，并未完全消除依赖淋巴细胞功能相关抗原-1（LFA-1）的杀伤作用。这些数据表明，即使在Neuro-2a/ICAM-1+细胞中，其他LFA-1配体也参与了效应细胞与靶细胞的相互作用。因此，我们检测了这些细胞系中ICAM-2的表达。Neuro-2a/LN和Neuro-2a/ICAM-1+细胞系均表达ICAM-2（MCF分别为16.4和16.5）。在ICAM-1阴性靶细胞Neuro-2a/LN中，ICAM-2在依赖LFA-1的杀伤作用中占主要部分，而ICAM-1在ICAM-1+转染细胞的细胞溶解中起主要作用。在抗ICAM-1和ICAM-2 mAb存在的情况下，细胞溶解的抑制作用与添加抗LFA-1 mAb时相当，表明该系统中没有其他LFA-1配体参与。ICAM-1的表达与体内致瘤性降低相关，接种Neuro-2a/ICAM-1+细胞的小鼠比接种Neuro-2a/LN细胞的小鼠存活时间显著延长（中位生存时间分别为35.5天和24.5天）（P < 0.001）。需要注意的是，小鼠神经母细胞瘤的ICAM-1转染并未改变其转移潜能。我们得出结论，小鼠神经母细胞瘤转染ICAM-1后，其对体外细胞溶解的敏感性增加，体内致瘤性降低。在ICAM-1阴性的小鼠神经母细胞瘤细胞中，ICAM-2在细胞介导的溶解过程中起主要作用。
