Department of Bone Marrow Transplantation & Cellular Therapy, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.
Graduate School of Biomedical Sciences, St. Jude Children's Research Hospital, Memphis, Tennessee, USA.
J Immunother Cancer. 2024 Nov 20;12(11):e009743. doi: 10.1136/jitc-2024-009743.
Oncofetal splice variants of extracellular matrix (ECM) proteins present a unique group of target antigens for the immunotherapy of pediatric cancers. However, limited data is available if these splice variants can be targeted with T cells expressing chimeric antigen receptors (CARs).
To determine the expression of the oncofetal version of tenascin C (TNC) encoding the C domain (C.TNC) in pediatric brain and solid tumors, we used quantitative reverse transcription PCR and immunohistochemistry. Genetically modified T cells were generated from human peripheral blood mononuclear cells and evaluated in vitro and in vivo.
We demonstrate that C.TNC is expressed on a protein level in pediatric tumors, including diffuse intrinsic pontine glioma, osteosarcoma, rhabdomyosarcoma, and Ewing sarcoma. We generate C.TNC-CAR T cells and establish that these recognize and kill C.TNC-positive tumor cells. However, their antitumor activity in vivo is limited. To improve the effector function of C.TNC-CAR T cells, we design a leucine zipper-based chimeric cytokine receptor that activates interleukin-18 signaling pathways (Zip18R). Expression of Zip18R in C.TNC-CAR T cells improves their ability to secrete cytokines and expand in repeat stimulation assays. C.TNC-CAR.Zip18R T cells also have significantly greater antitumor activity in vivo compared with unmodified C.TNC-CAR T cells.
Our study identifies the C domain of the ECM protein TNC as a promising CAR T-cell therapy for pediatric solid tumors and brain tumors. While we focus here on pediatric cancer, our work has relevance to a broad range of adult cancers that express C.TNC.
细胞外基质（ECM）蛋白的癌胚剪接变体为儿科癌症的免疫治疗提供了一组独特的靶抗原。然而，如果这些剪接变体可以被表达嵌合抗原受体（CAR）的 T 细胞靶向，可用的数据有限。
为了确定编码 C 结构域（C.TNC）的 tenascin C（TNC）的癌胚变体在儿科脑和实体瘤中的表达，我们使用定量逆转录 PCR 和免疫组织化学法。从人外周血单核细胞中生成基因修饰的 T 细胞，并在体外和体内进行评估。
我们证明 C.TNC 在包括弥漫性内在脑桥胶质瘤、骨肉瘤、横纹肌肉瘤和尤文肉瘤在内的儿科肿瘤中在蛋白质水平上表达。我们生成了 C.TNC-CAR T 细胞，并证实这些细胞识别并杀死 C.TNC 阳性肿瘤细胞。然而，它们在体内的抗肿瘤活性有限。为了提高 C.TNC-CAR T 细胞的效应功能，我们设计了一种基于亮氨酸拉链的嵌合细胞因子受体，该受体激活白细胞介素-18 信号通路（Zip18R）。Zip18R 在 C.TNC-CAR T 细胞中的表达可改善其分泌细胞因子和在重复刺激测定中扩增的能力。与未修饰的 C.TNC-CAR T 细胞相比，C.TNC-CAR.Zip18R T 细胞在体内也具有显著更强的抗肿瘤活性。
我们的研究将 ECM 蛋白 TNC 的 C 结构域鉴定为儿科实体瘤和脑肿瘤的有前途的 CAR T 细胞治疗方法。虽然我们在这里重点关注儿科癌症，但我们的工作与表达 C.TNC 的广泛的成人癌症相关。
