具有突变 Fc 间隔片段的 Hu8F4-CAR T 细胞可提高靶标特异性并介导体内抗白血病活性。
Hu8F4-CAR T cells with mutated Fc spacer segment improve target specificity and mediate anti-leukemia activity in vivo.
发表日期：2024 Jul 03
作者：
Hong He, Rolando A Vedia, Sijie Lu, Qiaochuan Li, Kathryn R Cox, Lisa St John, Anna Sergeeva, Karen Clise-Dwyer, Gheath Alatrash, Elizabeth J Shpall, Qing Ma, Jeffrey J Molldrem
来源：
CYTOTHERAPY
摘要：
Hu8F4 是一种 T 细胞受体样抗体，对白血病相关抗原 PR1/HLA-A2 表位具有高亲和力。 Hu8F4-CAR采用嵌合抗原受体（CAR）形式，由Hu8F4单链可变片段、人IgG1 CH2CH3胞外间隔结构域、人CD28共刺激结构域和人CD3ze信号结构域组成。我们已经在体外证明了 Hu8F4-CAR-T 细胞对表达 PR1/HLA-A2 的细胞系和来自急性髓系白血病患者的白血病母细胞的高效作用。先前的研究表明，修饰 IgG4 CH2CH3 间隔区的 Fc 结构域可以消除由小鼠 Fc γ 受体表达细胞介导的激活诱导的细胞死亡和脱靶杀伤。我们生成了具有突变 Fc 受体结合的 Hu8F4-CAR(PQ) Hu8F4-CAR CH2 结构域上的位点，可防止体内与 Fc gamma 受体表达细胞发生不必要的相互作用。用 Hu8F4-CAR(PQ) 转导的原代人 T 细胞可以在体外特异性裂解 HLA-A2 PR1 表达白血病细胞系。此外，成人供体来源和脐带血来源的 Hu8F4-CAR(PQ)-T 细胞均具有活性，并且可以消除 NSG 小鼠中的 U937 白血病细胞。在此，我们证明基于 IgG1 的间隔区的修饰可以消除 Fc 受体结合-引起的不良反应和Hu8F4-CAR(PQ)-T细胞可以在体内杀死白血病。版权所有©2024国际细胞学会
Hu8F4 is a T-cell receptor-like antibody with high affinity for the leukemia-associated antigen PR1/HLA-A2 epitope. Adapted into a chimeric antigen receptor (CAR) format, Hu8F4-CAR is composed of the Hu8F4 single-chain variable fragment, the human IgG1 CH2CH3 extracellular spacer domain, a human CD28 costimulatory domain and the human CD3ζ signaling domain. We have demonstrated high efficacy of Hu8F4-CAR-T cells against PR1/HLA-A2-expressing cell lines and leukemic blasts from patients with acute myeloid leukemia in vitro. Previous studies have shown that modification of the Fc domains of IgG4 CH2CH3 spacer regions can eliminate activation-induced cell death and off-target killing mediated by mouse Fc gamma receptor-expressing cells.We generated Hu8F4-CAR(PQ) with mutated Fc receptor binding sites on the CH2 domain of Hu8F4-CAR to prevent unwanted interactions with Fc gamma receptor-expressing cells in vivo.The primary human T cells transduced with Hu8F4-CAR(PQ) can specifically lyse HLA-A2+ PR1-expressing leukemia cell lines in vitro. Furthermore, both adult donor-derived and cord blood-derived Hu8F4-CAR(PQ)-T cells are active and can eliminate U937 leukemia cells in NSG mice.Herein, we demonstrate that modification of the IgG1-based spacer can eliminate Fc receptor binding-induced adverse effects and Hu8F4-CAR(PQ)-T cells can kill leukemia in vivo.Copyright © 2024 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.