Institute of Pathology, University Medical Center Mannheim, University of Heidelberg, Mannheim, Germany.
Am J Pathol. 2013 Jun;182(6):2121-31. doi: 10.1016/j.ajpath.2013.02.017. Epub 2013 Apr 2.
Cellular immunotherapy may provide a strategy to overcome the poor prognosis of metastatic and recurrent rhabdomyosarcoma (RMS) under the current regimen of polychemotherapy. Because little is known about resistance mechanisms of RMS to cytotoxic T cells, we investigated RMS cell lines and biopsy specimens for expression and function of immune costimulatory receptors and anti-apoptotic molecules by RT-PCR, Western blot analysis, IHC, and cytotoxicity assays using siRNA or transfection-modified RMS cell lines, together with engineered RMS-directed cytotoxic T cells specific for the fetal acetylcholine receptor. We found that costimulatory CD80 and CD86 were consistently absent from all RMSs tested, whereas inducible T-cell co-stimulator ligand (ICOS-L; alias B7H2) was expressed by a subset of RMSs and was inducible by tumor necrosis factor α in two of five RMS cell lines. Anti-apoptotic survivin, along with other inhibitor of apoptosis (IAP) family members (cIAP1, cIAP2, and X-linked inhibitor of apoptosis protein), was overexpressed by RMS cell lines and biopsy specimens. Down-regulation of survivin by siRNA or pharmacologically in RMS cells increased their susceptibility toward a T-cell attack, whereas induction of ICOS-L did not. Treatment of RMS-bearing Rag(-/-) mice with fetal acetylcholine receptor-specific chimeric T cells delayed xenograft growth; however, this happened without definitive tumor eradication. Combined blockade of survivin and application of chimeric T cells in vivo suppressed tumor proliferation during survivin inhibition. In conclusion, survivin blockade provides a strategy to sensitize RMS cells for T-cell-based therapy.
细胞免疫疗法可能为克服当前多化疗方案下转移性和复发性横纹肌肉瘤(RMS)的不良预后提供一种策略。由于对 RMS 细胞对细胞毒性 T 细胞的耐药机制知之甚少,我们通过 RT-PCR、Western blot 分析、免疫组化和使用 siRNA 或转染修饰的 RMS 细胞系以及针对胎儿乙酰胆碱受体的工程 RMS 定向细胞毒性 T 细胞进行了细胞系和活检标本的研究,以检测免疫共刺激受体和抗凋亡分子的表达和功能。我们发现,所有测试的 RMS 中均一致缺乏共刺激 CD80 和 CD86,而可诱导 T 细胞共刺激配体(ICOS-L;别名 B7H2)在一部分 RMS 中表达,并在五种 RMS 细胞系中的两种中可被肿瘤坏死因子α诱导。抗凋亡蛋白 survivin 以及其他凋亡抑制剂(IAP)家族成员(cIAP1、cIAP2 和 X 连锁凋亡抑制剂蛋白)在 RMS 细胞系和活检标本中过表达。通过 siRNA 或药理学下调 survivin 可增加 RMS 细胞对 T 细胞攻击的敏感性,而诱导 ICOS-L 则没有。用胎儿乙酰胆碱受体特异性嵌合 T 细胞治疗携带 RMS 的 Rag(-/-) 小鼠可延迟异种移植物的生长;然而,并没有明确的肿瘤消除。在体内联合阻断 survivin 并应用嵌合 T 细胞可在 survivin 抑制期间抑制肿瘤增殖。总之,survivin 阻断为提高 RMS 细胞对基于 T 细胞的治疗的敏感性提供了一种策略。