Chen Cheng, Li Kesang, Jiang Hua, Song Fei, Gao Huiping, Pan Xiaorong, Shi Bizhi, Bi Yanyu, Wang Huamao, Wang Hongyang, Li Zonghai
State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiaotong University School of Medicine, No. 25/Ln2200, XieTu Road, Shanghai, China.
CARsgen Therapeutics, Shanghai, China.
Cancer Immunol Immunother. 2017 Apr;66(4):475-489. doi: 10.1007/s00262-016-1949-8. Epub 2016 Dec 29.
Adoptive immunotherapy leveraging chimeric antigen receptor-modified T (CAR-T) cells holds great promise for the treatment of cancer. However, tumor-associated antigens often have low expression levels in normal tissues, which can cause on-target, off-tumor toxicity. Recently, we reported that GPC3-targeted CAR-T cells could eradicate hepatocellular carcinoma (HCC) xenografts in mice. However, it remains unknown whether on-target, off-tumor toxicity can occur. Therefore, we proposed that dual-targeted CAR-T cells co-expressing glypican-3 (GPC3) and asialoglycoprotein receptor 1 (ASGR1) (a liver tissue-specific protein)-targeted CARs featuring CD3ζ and 28BB (containing both CD28 and 4-1BB signaling domains), respectively, may have reduced on-target, off-tumor toxicity. Our results demonstrated that dual-targeted CAR-T cells caused no cytotoxicity to ASGR1GPC3 tumor cells, but they exhibited a similar cytotoxicity against GPC3ASGR1 and GPC3ASGR1 HCC cells in vitro. We found that dual-targeted CAR-T cells showed significantly higher cytokine secretion, proliferation and antiapoptosis ability against tumor cells bearing both antigens than single-targeted CAR-T cells in vitro. Furthermore, the dual-targeted CAR-T cells displayed potent growth suppression activity on GPC3ASGR1 HCC tumor xenografts, while no obvious growth suppression was seen with single or double antigen-negative tumor xenografts. Additionally, the dual-targeted T cells exerted superior anticancer activity and persistence against single-targeted T cells in two GPC3ASGR1 HCC xenograft models. Together, T cells carrying two complementary CARs against GPC3 and ASGR1 may reduce the risk of on-target, off-tumor toxicity while maintaining relatively potent antitumor activities on GPC3ASGR1 HCC.
利用嵌合抗原受体修饰的T（CAR-T）细胞进行过继性免疫治疗在癌症治疗方面具有巨大潜力。然而，肿瘤相关抗原在正常组织中的表达水平往往较低，这可能导致靶向非肿瘤毒性。最近，我们报道了靶向GPC3的CAR-T细胞可以根除小鼠体内的肝细胞癌（HCC）异种移植瘤。然而，尚不清楚是否会发生靶向非肿瘤毒性。因此，我们提出共表达硫酸乙酰肝素蛋白聚糖-3（GPC3）和去唾液酸糖蛋白受体1（ASGR1，一种肝组织特异性蛋白）的双靶点CAR-T细胞，其靶向CAR分别具有CD3ζ和28BB（包含CD28和4-1BB信号域），可能会降低靶向非肿瘤毒性。我们的结果表明，双靶点CAR-T细胞对ASGR1GPC3肿瘤细胞没有细胞毒性，但在体外对GPC3ASGR1和GPC3ASGR1 HCC细胞表现出相似的细胞毒性。我们发现，在体外，双靶点CAR-T细胞对携带两种抗原的肿瘤细胞的细胞因子分泌、增殖和抗凋亡能力明显高于单靶点CAR-T细胞。此外，双靶点CAR-T细胞对GPC3ASGR1 HCC肿瘤异种移植瘤显示出强大的生长抑制活性，而单抗原或双抗原阴性肿瘤异种移植瘤则未见明显的生长抑制。此外，在两个GPC3ASGR1 HCC异种移植模型中，双靶点T细胞对单靶点T细胞具有更强的抗癌活性和持久性。总之，携带针对GPC3和ASGR1的两种互补CAR的T细胞可能会降低靶向非肿瘤毒性的风险，同时在GPC3ASGR1 HCC上保持相对较强的抗肿瘤活性。
