肿瘤细胞治疗研究
英文原题：Chimeric switch scaffold protein augments CAR synapse formation and signaling networks.
这些发现确立了 PLAT 作为一种基于支架的策略，其通过将免疫检查点结合转化为 LAT 依赖的近端信号恢复，直接解决 CAR 固有的信号缺陷。
背景：嵌合抗原受体（CAR）T细胞疗法已在血液系统恶性肿瘤中取得临床成功，但在实体瘤中的应用仍受到免疫检查点介导的抑制及内在信号传导局限的制约。与T细胞受体（TCR）不同，CAR难以有效募集T细胞活化连接蛋白（LAT）信号复合体，导致信号传递不足和免疫突触结构不稳定。 方法：为解决这一局限，我们构建了程序性细胞死亡蛋白1（PD-1）-LAT嵌合开关支架（PLAT），将PD-1结合与依赖LAT的近端信号传导相连接。我们通过生化信号检测、定量成像分析、慢性抗原刺激模型和体内异种移植验证，比较表达PLAT的HER2 CAR T细胞与表达传统PD-1-CD28开关受体或显性负性PD-1的细胞在信号动力学、突触结构和抗肿瘤疗效方面的差异。 结果：PD-1配体结合后，PLAT增强LAT磷酸化，并形成与LAT相关的信号复合体。这使CAR免疫突触重组为同心、类似TCR的结构，恢复近端信号强度。信号重编程增强了钙流和NFAT/NF-κB活化，进而提高细胞毒性、持续增殖能力，并增强其在慢性抗原暴露下抵抗功能耗竭的能力。直接比较显示，PLAT的早期功能反应优于传统PD-1-CD28开关受体；与显性负性PD-1策略相比，其体内功能持久性和抗肿瘤活性也更强。 结论：这些发现确立了PLAT这一支架策略，它通过将免疫检查点结合转化为依赖LAT的近端信号恢复，直接弥补CAR信号传导的内在不足。本研究为在免疫抑制性肿瘤环境中构建功能更强、持久性更好的CAR T细胞提供了新思路。
BACKGROUND: Chimeric antigen receptor (CAR) T-cell therapy has achieved clinical success in hematologic malignancies, but remains limited in solid tumors due to immune checkpoint-mediated suppression and intrinsic signaling constraints. Unlike T-cell receptors (TCRs), CARs fail to efficiently recruit the linker for activation of T cells (LAT) signalosome, resulting in suboptimal signal propagation and unstable immunological synapse organization. METHODS: To address this limitation, we engineered a programmed cell death protein 1 (PD-1)-LAT (PLAT) chimeric switch scaffold that couples PD-1 engagement to LAT-dependent proximal signaling. We compared the signaling kinetics, synaptic architecture, and antitumor efficacy of PLAT-expressing HER2 CAR T cells against those expressing conventional PD-1-CD28 switch receptors or dominant-negative PD-1 using biochemical signaling assays, quantitative imaging analysis, chronic antigen stimulation models, and in vivo xenograft validation. RESULTS: PLAT enhanced LAT phosphorylation and nucleated LAT-associated signaling complexes on programmed death-ligand 1 engagement. This reorganized the CAR immune synapse into a concentric, TCR-like architecture, restoring proximal signaling strength. This signaling reprogramming resulted in increased calcium flux and NFAT/NF- B activation, driving enhanced cytotoxicity, sustained proliferation, and resistance to functional exhaustion under chronic antigen exposure. In direct comparisons, PLAT outperformed conventional PD-1-CD28 switch receptors in early functional responses and demonstrated superior functional durability and antitumor activity in vivo compared with dominant-negative PD-1 strategies. CONCLUSIONS: These findings establish PLAT as a scaffold-based strategy that directly addresses intrinsic CAR signaling deficiencies by converting immune checkpoint engagement into LAT-dependent proximal signaling restoration. This work provides a new framework for engineering CAR T cells with improved function and persistence in immunosuppressive tumor environments.
MEMBER ACCOUNT
登录成功会直接打开下一页。
