Darcy P K, Kershaw M H, Trapani J A, Smyth M J
Cellular Cytotoxicity Laboratory, The Austin Research Institute, Heidelberg, Victoria, Australia.
Eur J Immunol. 1998 May;28(5):1663-72. doi: 10.1002/(SICI)1521-4141(199805)28:05<1663::AID-IMMU1663>3.0.CO;2-L.
In the MD45 mouse cytotoxic T lymphocyte (CTL) hybridoma cell line, we have expressed a chimeric receptor, consisting of the single-chain variable domains (scFv) of anti-carcinoma embryonic antigen (CEA) mAb linked to Fcgamma receptor (FcgammaR) chain via a CD8 hinge. Transfected MD45 subclones lysed CEA-positive human colon carcinoma cell lines in an antigen-specific and FasL-dependent manner. The degree of lysis correlated with the level of chimeric receptor expressed on transduced MD45 subclones. The requirement for an intact Y65TGL motif in the signaling gamma chain suggested that interaction of the chimeric receptor with target cell CEA induced the cytotoxicity of MD45-scFv subclones. However, MD45 expressing a Y65F mutant chimera still displayed minor levels of lysis following PMA stimulation, suggesting that PMA could bypass gamma chain induction of functional FasL. Pretreatment of Fas-resistant CEA-positive colon carcinoma target cells with IFN-gamma increased their sensitivity of MD45-scFv subclones and FasL-mediated lysis. This study has demonstrated the successful activation of FasL function via a chimeric receptor introduced into lymphocytes and the susceptibility of human colon carcinoma to combined cytokine and CTL treatment.
在MD45小鼠细胞毒性T淋巴细胞（CTL）杂交瘤细胞系中，我们表达了一种嵌合受体，它由抗癌胚抗原（CEA）单克隆抗体的单链可变区（scFv）通过CD8铰链区与Fcγ受体（FcγR）链相连组成。转染的MD45亚克隆以抗原特异性和FasL依赖的方式裂解CEA阳性的人结肠癌细胞系。裂解程度与转导的MD45亚克隆上表达的嵌合受体水平相关。信号γ链中完整的Y65TGL基序的需求表明嵌合受体与靶细胞CEA的相互作用诱导了MD45-scFv亚克隆的细胞毒性。然而，表达Y65F突变嵌合体的MD45在PMA刺激后仍显示出较低水平的裂解，这表明PMA可以绕过γ链对功能性FasL的诱导。用IFN-γ预处理对Fas耐药的CEA阳性结肠癌靶细胞可增加其对MD45-scFv亚克隆和FasL介导的裂解的敏感性。本研究证明了通过引入淋巴细胞的嵌合受体成功激活FasL功能以及人结肠癌对细胞因子和CTL联合治疗的敏感性。
