Department of Hematology, Oncology, Clinical Immunology and Rheumatology, University Hospital Tübingen, Tübingen, Germany.
Department of Oncology, Hematology and Rheumatology, University Hospital Heidelberg, Heidelberg, Germany.
J Immunother Cancer. 2024 Jan 31;12(1):e007829. doi: 10.1136/jitc-2023-007829.
Relapse and graft-versus-host disease (GVHD) are the main causes of death after allogeneic hematopoietic cell transplantation (HCT). Preclinical murine models and clinical data suggest that invariant natural killer T (iNKT) cells prevent acute and chronic GVHD. In addition, iNKT cells are crucial for efficient immune responses against malignancies and contribute to reduced relapse rates after transplantation. Chimeric antigen receptors (CAR) redirect effector cells to cell surface antigens and enhance killing of target cells. With this study, we aimed to combine enhanced cytotoxicity of CD19-CAR-iNKT cells against lymphoma cells with their tolerogenic properties.
iNKT cells were isolated from peripheral blood mononuclear cells and transduced with an anti-CD19-CAR retrovirus. After in vitro expansion, the functionality of CD19-CAR-iNKT cells was assessed by flow cytometry, image stream analysis and multiplex analysis in single-stimulation or repeated-stimulation assays. Moreover, the immunoregulatory properties of CD19-CAR-iNKT cells were analyzed in apoptosis assays and in mixed lymphocyte reactions. The effect of checkpoint inhibition through nivolumab was analyzed in these settings.
In this study, we could show that the cytotoxicity of CD19-CAR-iNKT cells was mediated either through engagement of their CAR or their invariant T-cell receptor, which may circumvent loss of response through antigen escape. However, encounter of CD19-CAR-iNKT cells with their target induced a phenotype of exhaustion. Consequently, checkpoint inhibition increased cytokine release, cytotoxicity and survival of CD19-CAR-iNKT cells. Additionally, they showed robust suppression of alloreactive immune responses.
In this work, we demonstrate that CAR-iNKT cells are a powerful cytotherapeutic option to prevent or treat relapse while potentially reducing the risk of GVHD after allogeneic HCT.
同种异体造血细胞移植（HCT）后，复发和移植物抗宿主病（GVHD）是导致死亡的主要原因。临床前的小鼠模型和临床数据表明，固有自然杀伤 T（iNKT）细胞可预防急性和慢性 GVHD。此外，iNKT 细胞对于有效的抗肿瘤免疫反应至关重要，并有助于降低移植后复发率。嵌合抗原受体（CAR）将效应细胞重定向至细胞表面抗原，并增强对靶细胞的杀伤作用。本研究旨在将针对淋巴瘤细胞的 CD19-CAR-iNKT 细胞的增强细胞毒性与它们的免疫耐受特性相结合。
从外周血单核细胞中分离 iNKT 细胞，并通过抗 CD19-CAR 逆转录病毒进行转导。在体外扩增后，通过流式细胞术、图像流分析和多重分析在单次刺激或重复刺激实验中评估 CD19-CAR-iNKT 细胞的功能。此外，还分析了 CD19-CAR-iNKT 细胞在凋亡实验和混合淋巴细胞反应中的免疫调节特性。在这些情况下分析了通过 nivolumab 进行的检查点抑制的效果。
在这项研究中，我们能够表明 CD19-CAR-iNKT 细胞的细胞毒性通过其 CAR 或其不变 T 细胞受体的参与来介导，这可能规避通过抗原逃逸导致的反应丧失。然而，CD19-CAR-iNKT 细胞与靶细胞的接触诱导了衰竭表型。因此，检查点抑制增加了 CD19-CAR-iNKT 细胞的细胞因子释放、细胞毒性和存活率。此外，它们表现出对同种异体免疫反应的强大抑制作用。
在这项工作中，我们证明了 CAR-iNKT 细胞是一种强大的细胞治疗选择，可以预防或治疗复发，同时降低同种异体 HCT 后发生 GVHD 的风险。
