Regulatory T cells (T regs ) make major contributions to immune homeostasis. Because T reg dysfunction can lead to both allo- and autoimmunity, there is interest in correcting these disorders through T reg adoptive transfer. Two of the central challenges in clinically deploying T reg cellular therapies are ensuring phenotypic stability and maximizing potency. Here, we describe an approach to address both issues through the creation of OX40 ligand (OX40L)–specific chimeric antigen receptor (CAR)–T regs under the control of a synthetic forkhead box P3 ( FOXP3 ) promoter. The creation of these CAR-T regs enabled selective T reg stimulation by engagement of OX40L, a key activation antigen in alloimmunity, including both graft-versus-host disease and solid organ transplant rejection, and autoimmunity, including rheumatoid arthritis, systemic sclerosis, and systemic lupus erythematosus. We demonstrated that OX40L–CAR-T regs were robustly activated in the presence of OX40L-expressing cells, leading to up-regulation of T reg suppressive proteins without induction of proinflammatory cytokine production. Compared with control T regs , OX40L–CAR-T regs more potently suppressed alloreactive T cell proliferation in vitro and were directly inhibitory toward activated monocyte-derived dendritic cells (DCs). We identified trogocytosis as one of the central mechanisms by which these CAR-T regs effectively decrease extracellular display of OX40L, resulting in decreased DC stimulatory capacity. OX40L–CAR-T regs demonstrated an enhanced ability to control xenogeneic graft-versus-host disease compared with control T regs without abolishing the graft-versus-leukemia effect. These results suggest that OX40L–CAR-T regs may have wide applicability as a potent cellular therapy to control both allo- and autoimmune diseases.

中文翻译：

---

人 OX40L-CAR-T regs 靶向活化的抗原呈递细胞并控制 T 细胞同种异体反应性


调节性 T 细胞 （T regs ） 对免疫稳态做出重大贡献。由于 T reg 功能障碍可导致同种异体免疫和自身免疫，因此人们有兴趣通过 T reg 过继转移来纠正这些疾病。临床部署 T reg 细胞疗法的两个主要挑战是确保表型稳定性和最大化效力。在这里，我们描述了一种通过在合成叉头盒 P3 （FOXP3） 启动子的控制下创建 OX40 配体 （OX40L） 特异性嵌合抗原受体 （CAR）-T regs 来解决这两个问题的方法。这些 CAR-T regs 的产生使 OX40L 能够通过参与选择性 T reg 刺激，OX40L 是同种免疫中的关键激活抗原，包括移植物抗宿主病和实体器官移植排斥反应，以及自身免疫，包括类风湿性关节炎、系统性硬化症和系统性红斑狼疮。我们证明，在表达 OX40L 的细胞存在下，OX40L-CAR-T regs 被强烈激活，导致 T reg 抑制蛋白上调，而不诱导促炎细胞因子的产生。与对照 T regs 相比，OX40L-CAR-T regs 在体外更有效地抑制同种异体反应性 T 细胞增殖，并直接抑制活化的单核细胞衍生的树突状细胞 （DC）。我们发现胞吞作用是这些 CAR-T regs 有效减少 OX40L 细胞外显示的核心机制之一，导致 DC 刺激能力降低。与对照 T reg 相比，OX40L-CAR-T regs 显示出更强的控制异种遗传移植物抗宿主病的能力，而不会消除移植物抗白血病效应。 这些结果表明，OX40L-CAR-T regs 可能作为一种有效的细胞疗法具有广泛的适用性，以控制同种异体免疫性疾病和自身免疫性疾病。