同种异体 CAR-T 细胞 HLA-A/B 和 TRAC 缺失具有针对 B 细胞恶性肿瘤的抗肿瘤潜力。

BACKGROUND: Although chimeric antigen receptor T (CAR-T) cells have been proven to be an effective way of treating B cell malignancies, a lot of patients could not benefit from it because of failure in CAR-T cell manufacturing, disease progression, and unaffordable price. The study aimed to explore universal CAR-T cell products to extend the clinical accessibility. METHODS: The antitumor activity of CRISPR/Cas9-edited allogeneic anti-CD19 CAR-T (CAR-T19) cells was assessed in vitro, in animal models, and in patients with relapsed/refractory (R/R) acute B cell lymphoblastic leukemia (B-ALL) or diffuse large B cell lymphoma. RESULTS: B2M/TRAC universal CAR-T19 (U-CAR-T19) cells exhibited powerful anti-leukemia abilities both in vitro and in animal models, as did primary CD19 leukemia cells from leukemia patients. However, expansion, antitumor efficacy, or graft-versus-host-disease (GvHD) was not observed in six patients with R/R B cell malignancies after U-CAR-T19 cell infusion. Accordingly, significant activation of natural killer (NK) cells by U-CAR-T19 cells was proven both clinically and in vitro. HLA-A/B/TRAC novel CAR-T19 (nU-CAR-T19) cells were constructed with similar tumoricidal capacity but resistance to NK cells in vitro. Surprisingly, robust expansion of nU-CAR-T19 cells, along with rapid eradication of CD19 abnormal B cells, was observed in the peripheral blood and bone marrow of another three patients with R/R B-ALL. The patients achieved complete remission with no detectable minimal residual disease 14 days after the infusion of nU-CAR-T19 cells. Two of the three patients had grade 2 cytokine release syndrome, which were managed using an IL-6 receptor blocker. Most importantly, GvHD was not observed in any patient, suggesting the safety of TRAC-disrupted CAR-T cells generated using the CRISPR/Cas9 method for clinical application. CONCLUSIONS: The nU-CAR-T19 cells showed a strong response in R/R B-ALL. nU-CAR-T19 cells have the potential to be a promising new approach for treating R/R B cell malignancies.

背景：嵌合抗原受体 T（CAR-T）细胞已被证明是治疗 B 细胞恶性肿瘤的有效方法，但由于 CAR-T 细胞制造失败、疾病进展和无法负担的价格，很多患者无法从中受益。本研究旨在探索通用的 CAR-T 细胞产品，以扩大临床应用的可及性。

方法：评估了 CRISPR/Cas9 编辑的同种异体抗 CD19 CAR-T（CAR-T19）细胞在体外、动物模型中和复发/难治性（R/R）急性 B 细胞淋巴母细胞白血病（B-ALL）或弥漫性大 B 细胞淋巴瘤患者中的抗肿瘤活性。

结果：B2M/TRAC 通用 CAR-T19（U-CAR-T19）细胞在体外和动物模型中均表现出强大的抗白血病能力，来自白血病患者的原发性 CD19 白血病细胞也是如此。然而，在 6 名 R/R B 细胞恶性肿瘤患者输注 U-CAR-T19 细胞后，并未观察到细胞扩增、抗肿瘤疗效或移植物抗宿主病（GvHD）。因此，在临床上和体外均证明 U-CAR-T19 细胞能显著激活自然杀伤（NK）细胞。构建了具有类似杀伤能力但在体外能抵抗 NK 细胞的 HLA-A/B/TRAC 新型 CAR-T19（nU-CAR-T19）细胞。令人惊讶的是，在另外 3 名 R/R B-ALL 患者的外周血和骨髓中观察到 nU-CAR-T19 细胞的快速扩增，同时迅速清除 CD19 异常 B 细胞。输注 nU-CAR-T19 细胞 14 天后，患者达到完全缓解，无最小残留疾病可检测。3 名患者中有 2 名发生 2 级细胞因子释放综合征，使用 IL-6 受体阻滞剂进行了治疗。最重要的是，任何患者均未观察到 GvHD，这表明使用 CRISPR/Cas9 方法生成的 TRAC 缺失 CAR-T 细胞用于临床应用是安全的。

结论：nU-CAR-T19 细胞在 R/R B-ALL 中表现出强烈的反应。nU-CAR-T19 细胞有可能成为治疗 R/R B 细胞恶性肿瘤的一种很有前途的新方法。