Department of Drug Development I, CellabMED Inc., Seoul, South Korea.
Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, Goyang, South Korea.
Front Immunol. 2021 Nov 8;12:715000. doi: 10.3389/fimmu.2021.715000. eCollection 2021.
Interleukin-13 receptor α 2 (IL13Rα2) is a promising tumor-directed antigen of malignant glioma (MG). Here, we examine the efficacy and safety of T cells containing a YYB-103 chimeric antigen receptor (CAR) that can preferentially bind to IL13Rα2 on MG cells.
IL13 was modified on the extracellular domain by substitution of amino acids with E13K, R66D, S69D, and R109K and stably transfected into human T cells using a retroviral vector. The efficacy of YYB-103 CAR T cells was tested in cell lines with differing IL13Rα1 and IL13Rα2 expression. The efficacy of intracerebroventricular (i.c.v.) and intravenous (i.v.) routes of YYB-103 CAR T-cell administration were tested in orthotopic MG mouse models. Immunohistochemical staining of MG was performed using WHO grade 3/4 surgical specimens from 53 patients. IL13Rα2 expression was quantified by H-score calculated from staining intensity and percentage of positive cells.
Binding affinity assay of YYB-103 verified apparently nil binding to IL13Rα1, which was more selective than previously reported IL13 modification (E13Y). YYB-103 CAR T cells showed selective toxicity toward co-cultured U87MG (IL13Rα1/IL13Rα2) cells but not A431 (IL13Rα1/IL13Rα2) cells. Consistently, YYB-103 CAR T cells suppressed tumor growth in nude mice receiving orthotopic injection of U87 MG cells. Both i.c.v. and i.v. injections of YYB-103 CAR T cells reduced tumor volume and prolonged overall survival of tumor-bearing mice. The median H-score for IL13Rα2 in patient-derived MG tissue was 5 (mean, 57.5; SD, 87.2; range, 0 to 300).
This preclinical study demonstrates the efficacy of IL13Rα2-targeted YYB-103 CAR T cells against MG cells. The use of modified IL13 to construct a CAR facilitated the selective targeting of IL13Rα2-expressing MG cells while sparing IL13Rα1-expressing cells. Notably, YYB-103 CAR T cells exhibited effective blood-brain barrier crossing, suggesting compatibility with i.v. administration rather than intracranial injection. Additionally, the high H-score for IL13Rα2 in glioblastoma, especially in conjunction with the poor prognostic markers of wild-type isocitrate dehydrogenase-1 (IDH-1) and unmethylated -methyl guanine methyl-transferase (MGMT), could be used to determine the eligibility of patients with recurrent glioblastoma for a future clinical trial of YYB-103 CAR T cells.
白细胞介素-13 受体 α2（IL13Rα2）是恶性神经胶质瘤（MG）有前途的肿瘤导向抗原。在这里，我们研究了含有可优先与 MG 细胞上的 IL13Rα2 结合的 YYB-103 嵌合抗原受体（CAR）的 T 细胞的疗效和安全性。
通过用 E13K、R66D、S69D 和 R109K 取代氨基酸对 IL13 进行修饰，并使用逆转录病毒载体将其稳定转染入人 T 细胞中。在具有不同 IL13Rα1 和 IL13Rα2 表达的细胞系中测试了 YYB-103 CAR T 细胞的疗效。在原位 MG 小鼠模型中测试了经脑室（i.c.v.）和静脉（i.v.）途径给予 YYB-103 CAR T 细胞的疗效。使用来自 53 名患者的 WHO 分级 3/4 手术标本进行 MG 的免疫组织化学染色。通过从染色强度和阳性细胞百分比计算的 H 评分来量化 IL13Rα2 的表达。
YYB-103 的结合亲和力测定证实对 IL13Rα1 的结合明显为零，这比以前报道的 IL13 修饰（E13Y）更具选择性。YYB-103 CAR T 细胞对共培养的 U87MG（IL13Rα1/IL13Rα2）细胞表现出选择性毒性，但对 A431（IL13Rα1/IL13Rα2）细胞没有毒性。一致地，YYB-103 CAR T 细胞抑制了接受原位注射 U87 MG 细胞的裸鼠的肿瘤生长。i.c.v.和 i.v.给予 YYB-103 CAR T 细胞均可减少肿瘤体积并延长荷瘤小鼠的总生存期。源自患者的 MG 组织中 IL13Rα2 的中位数 H 评分为 5（平均值，57.5；标准差，87.2；范围，0 至 300）。
这项临床前研究证明了针对 MG 细胞的 IL13Rα2 靶向 YYB-103 CAR T 细胞的疗效。使用修饰的 IL13 构建 CAR 促进了对表达 IL13Rα2 的 MG 细胞的选择性靶向，同时避免了表达 IL13Rα1 的细胞。值得注意的是，YYB-103 CAR T 细胞表现出有效的血脑屏障穿透性，这表明与静脉内给药而不是颅内注射相容。此外，在胶质母细胞瘤中 IL13Rα2 的高 H 评分，特别是与野生型异柠檬酸脱氢酶-1（IDH-1）和未甲基化的 -甲基鸟嘌呤甲基转移酶（MGMT）的不良预后标志物相结合，可用于确定复发性胶质母细胞瘤患者是否有资格参加未来的 YYB-103 CAR T 细胞临床试验。
