背景:嵌合抗原受体T细胞(CAR-T)治疗已在B细胞恶性肿瘤患者中获得了显着缓解。然而,其治疗实体瘤的疗效仍然有限。这里,我们研究了使用工程长效白介素(IL)-7(rhIL-7-hyFc或NT-I7)和针对三种抗原的CAR-T细胞的联合治疗方法。磷脂酰肌醇蛋白聚糖-2(GPC2),磷脂酰肌醇蛋白聚糖-3(GPC3),和间皮素(MSLN),对抗包括肝癌在内的多种实体瘤类型,神经母细胞瘤,卵巢癌,和小鼠的胰腺癌。
方法:靶向GPC2,GPC3和MSLN的CAR-T细胞与NT-I7联合使用以评估抗癌活性。异种移植肿瘤模型,包括肝癌原位模型,使用移植有肝细胞癌细胞系的NODscidγ小鼠建立,神经母细胞瘤,卵巢癌,还有胰腺癌.通过生物发光体内肿瘤成像和使用卡尺测量肿瘤体积来监测小鼠。对NT-I7刺激下的CAR-T细胞的免疫表型进行记忆标志物评估,排气标记,和T细胞信号分子通过流式细胞术和蛋白质印迹。
结果:与IL-2组合相比,NT-I7的临床前评估显示实体瘤通过CD4+CAR-T的占有率增强消退,改善T细胞扩增,减少耗竭标记(程序性细胞死亡蛋白1或PD-1和淋巴细胞激活基因3或LAG-3)表达,和增加干细胞样记忆CAR-T细胞的产生。STAT5通路被证明是NT-I7信号的下游,由CAR-T细胞中IL-7受体表达的增加介导。此外,当与NT-I7联合使用时,CAR-T细胞在小鼠中提高了对低抗原密度肿瘤的功效,为具有异质性抗原特征的患者提供了一条途径。
结论:本研究为NT-I7加CAR-T细胞联合治疗人类实体瘤提供了理论基础。
BACKGROUND: Chimeric antigen receptor T-cell (CAR-T) therapy has achieved remarkable remission in patients with B-cell malignancies. However, its efficacy in treating solid tumors remains limited. Here, we investigated a combination therapy approach using an engineered long-acting interleukin (IL)-7 (rhIL-7-hyFc or NT-I7) and CAR-T cells targeting three antigens, glypican-2 (GPC2), glypican-3 (GPC3), and mesothelin (MSLN), against multiple solid tumor types including liver cancer, neuroblastoma, ovarian cancer, and pancreatic cancer in mice.
METHODS: CAR-T cells targeting GPC2, GPC3, and MSLN were used in combination with NT-I7 to assess the anticancer activity. Xenograft tumor models, including the liver cancer orthotopic model, were established using NOD scid gamma mice engrafted with cell lines derived from hepatocellular carcinoma, neuroblastoma, ovarian cancer, and pancreatic cancer. The mice were monitored by bioluminescence in vivo tumor imaging and tumor volume measurement using a caliper. Immunophenotyping of CAR-T cells on NT-I7 stimulation was evaluated for memory markers, exhaust markers, and T-cell signaling molecules by flow cytometry and western blotting.
RESULTS: Compared with the IL-2 combination, preclinical evaluation of NT-I7 exhibited regression of solid tumors via enhanced occupancy of CD4+ CAR-T, improved T-cell expansion, reduced exhaustion markers (programmed cell death protein 1 or PD-1 and lymphocyte-activation gene 3 or LAG-3) expression, and increased generation of stem cell-like memory CAR-T cells. The STAT5 pathway was demonstrated to be downstream of NT-I7 signaling, mediated by increased expression of the IL-7 receptor expression in CAR-T cells. Furthermore, CAR-T cells improved efficacy against tumors with low antigen density when combined with NT-I7 in mice, presenting an avenue for patients with heterogeneous antigenic profiles.
CONCLUSIONS: This study provides a rationale for NT-I7 plus CAR-T cell combination therapy for solid tumors in humans.