PO.IM01.06 · 免疫学
受调节性T细胞启发的CAR-T细胞工程化增强实体瘤中的抗肿瘤疗效
Regulatory T cell inspired engineering of CAR-T cells enhances anti-tumor efficacy in solid tumors
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
嵌合抗原受体(CAR)T细胞已彻底改变了血液系统恶性肿瘤的治疗。然而，由于以营养缺乏、低氧和乳酸积累为特征的免疫抑制性肿瘤微环境(TME)，其对实体瘤的疗效仍然有限。调节性T细胞(Treg)因表达转录因子FOXP3而能在此类条件下茁壮生长，FOXP3增强了它们在肿瘤内的适应性。利用这一生物学特性，我们工程化构建了过表达FOXP3的效应CAR-T细胞，并评估其在黑色素瘤中的治疗潜力。在体外，靶向黑色素瘤相关抗原TRP1的CAR-T细胞高效杀伤B16F10黑色素瘤细胞，FOXP3过表达略微降低了细胞毒性。我们接下来在携带B16F10黑色素瘤的免疫健全C57BL/6小鼠中测试了CD4+、CD8+或全部CAR-T细胞亚群。体内NanoLuc荧光素酶成像显示，表达FOXP3的CAR-T细胞相较于对照CAR-T细胞具有更优的持久性。引人注目的是，尽管常规CAR-T细胞表现出极低的肿瘤控制，FOXP3过表达却产生了分歧性的结果：单独使用CD4+或CD8+ CAR-FOXP3-T细胞出乎意料地加速了黑色素瘤生长，而全部CAR-FOXP3-T细胞则显著延缓了肿瘤进展。机制分析显示，FOXP3过表达并未改变CAR诱导的T细胞激活程度，但确实保护了CAR-T细胞免于激活诱导的细胞死亡。进一步表征显示，全部CAR-FOXP3-T细胞主要为CD8⁺，这促使我们假设补充CD4⁺ CAR-T细胞可增强抗肿瘤活性。事实上，共同给予CD4⁺ CAR-T细胞和全部CAR-FOXP3-T细胞在体内实现了对黑色素瘤生长的持续控制，表明这两种细胞群之间存在协同相互作用。我们的发现为克服实体瘤免疫治疗障碍的新型CAR-T细胞疗法设计原则提供了概念验证，并为下一代细胞疗法的开发提供了信息。
资助：本研究由授予LMRF的Swim Across America基金23-1579以及授予AC的MUSC卓越研究专门中心(SCORE)5U54DA016511-18试点项目奖资助。本研究部分得到南卡罗来纳医科大学Hollings癌症中心流式细胞术与细胞分选共享资源(P30 CA138313)的支持。
查看英文原文 English abstract
Chimeric antigen receptor (CAR)-T cells have revolutionized treatment for hematologic malignancies. Yet, their efficacy against solid tumors remains limited due to the immunosuppressive tumor microenvironment (TME), characterized by nutrient deprivation, hypoxia, and lactate accumulation. Regulatory T cells (Tregs) thrive under such conditions due to expression of the transcription factor FOXP3, which enhances their intratumoral fitness. Leveraging this biology, we engineered effector CAR-T cells to overexpress FOXP3 and evaluated their therapeutic potential in melanoma. In vitro , CAR-T cells targeting the melanoma-associated antigen TRP1 efficiently killed B16F10 melanoma cells, with FOXP3 overexpression modestly reducing cytotoxicity. We next tested CD4 + , CD8 + , or total CAR-T cell subsets in immunocompetent C57BL/6 mice bearing B16F10 melanomas. In vivo NanoLuc luciferase imaging revealed superior persistence of FOXP3-expressing CAR-T cells compared to control CAR-T cells. Strikingly, while conventional CAR-T cells exhibited minimal tumor control, FOXP3 overexpression produced divergent outcomes: CD4 + or CD8 + CAR-FOXP3-T cells alone unexpectedly accelerated melanoma growth, whereas total CAR-FOXP3-T cells significantly delayed tumor progression. Mechanistic analyses revealed that FOXP3 overexpression did not alter the extent of CAR-induced T cell activation but did protect CAR-T cells from activation-induced cell death. Further characterization revealed that total CAR-FOXP3-T cells were predominantly CD8⁺, leading us to hypothesize that supplemental CD4⁺ CAR-T cells could enhance anti-tumor activity. Indeed, co-administration of CD4⁺ CAR-T cells and total CAR-FOXP3-T cells resulted in sustained control of melanoma growth in vivo , indicating a synergistic interaction between the two cell populations. Our findings provide proof-of-concept for novel CAR-T cell therapy design principles to overcome barriers in solid tumor immunotherapy and inform the development of next-generation cellular therapies.
Funding: This work was supported by Swim Across America Grant 23-1579 to LMRF and an MUSC Specialized Center of Research Excellence (SCORE) 5U54DA016511-18 Pilot Project Award to AC. This study was supported in part by the Flow Cytometry and Cell Sorting Shared Resource, Hollings Cancer Center, Medical University of South Carolina (P30 CA138313).
利益披露 Disclosure
A. Chattopadhyay, None..
E. O’Connor, None..
L. M. R. Ferreira, None.