National Clinical Research Center for Hematologic Diseases, Jiangsu Institute of Hematology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China.
Department of Hematology, Huai'an Hospital Affiliated to Xuzhou Medical College, Huai'an Second People's Hospital, Huai'an, Jiangsu 223002, P.R. China.
Mol Med Rep. 2021 Mar;23(3). doi: 10.3892/mmr.2021.11847. Epub 2021 Jan 26.
The activation of chimeric antigen receptor (CAR)‑T cells can lead to persistently high levels of programmed cell death 1 (PD‑1) antigen and eventually causes the exhaustion of T cells. The effectiveness of CAR‑T cells targeting C‑type lectin‑like molecule‑1 (CLL‑1) combined with PD‑1 silencing therapy for acute myeloid leukemia (AML) was evaluated in the present study. CLL‑1 levels in primary AML bone marrow samples was examined using flow cytometric analysis. We designed a CLL‑1 CAR‑T, containing CLL‑1‑specific single‑chain variable fragment, CD28, OX40, CD8 hinge and TM and CD3‑ζ signaling domains. CLL‑1 CAR‑T with PD‑1 silencing was constructed. It was confirmed that CLL‑1 is expressed on the surface of AML cells. CLL‑1 CAR‑T showed specific lysing activity against CLL‑1 AML cells. PD‑1 silencing enhanced the killing ability of CLL‑1 CAR‑T. Furthermore, it was found that CAR‑T derived from healthy donor T cells was more effective in killing THP‑1 cells (a human acute monocytic leukemia cell line) than those from patient‑derived T cells. These results indicated that CLL‑1 CAR‑T and PD‑1 knockdown CLL‑1 CAR‑T could be used as a potential immunotherapy to treat relapsed or refractory AML.
嵌合抗原受体 (CAR) -T 细胞的激活可导致程序性细胞死亡 1 (PD-1) 抗原持续高水平，并最终导致 T 细胞耗竭。本研究评估了针对 C 型凝集素样分子 1 (CLL-1) 的 CAR-T 细胞与 PD-1 沉默疗法联合用于急性髓细胞白血病 (AML) 的疗效。采用流式细胞术分析检测原代 AML 骨髓样本中的 CLL-1 水平。我们设计了一种 CLL-1 CAR-T，包含 CLL-1 特异性单链可变片段、CD28、OX40、CD8 铰链和 TM 以及 CD3-ζ 信号结构域。构建了具有 PD-1 沉默功能的 CLL-1 CAR-T。证实 CLL-1 在 AML 细胞表面表达。CLL-1 CAR-T 对 CLL-1 AML 细胞具有特异性裂解活性。PD-1 沉默增强了 CLL-1 CAR-T 的杀伤能力。此外，还发现来自健康供体 T 细胞的 CAR-T 比来自患者来源的 T 细胞更有效地杀伤 THP-1 细胞 (一种人急性单核细胞白血病细胞系)。这些结果表明，CLL-1 CAR-T 和 PD-1 敲低 CLL-1 CAR-T 可作为治疗复发或难治性 AML 的潜在免疫疗法。
