Schindler Katharina, Ruppel Katharina Eva, Müller Claudia, Koehl Ulrike, Fricke Stephan, Schmiedel Dominik
Department for Cell and Gene Therapy Development, Fraunhofer Institute for Cell Therapy and Immunology (IZI), 04103 Leipzig, Germany.
Department of Preclinical Development and Validation, Fraunhofer Institute for Cell Therapy and Immunology (IZI), 04103 Leipzig, Germany.
Mol Ther Methods Clin Dev. 2024 Aug 22;32(3):101328. doi: 10.1016/j.omtm.2024.101328. eCollection 2024 Sep 12.
Chimeric antigen receptor (CAR) T cell therapies have demonstrated significant successes in treating cancer. Currently, there are six approved CAR T cell products available on the market that target different malignancies of the B cell lineage. However, to overcome the limitations of CAR T cell therapies, other immune cells are being investigated for CAR-based cell therapies. CAR natural killer (NK) cells can be applied as allogeneic cell therapy, providing an economical, safe, and efficient alternative to autologous CAR T cells. To improve CAR research and future in-patient monitoring of cell therapeutics, a simple, reliable, and versatile CAR detection reagent is crucial. As most existing CARs contain a single-chain variable fragment (scFv) with either a Whitlow or a G4S linker site, linker-specific monoclonal antibodies (mAbs) can detect a broad range of CARs. This study demonstrates that these linker-specific mAbs can detect different CAR NK cells , spiked in whole blood, and within patient-derived tumor spheroids with high specificity and sensitivity, providing an effective and almost universal alternative for scFv-based CAR detection. Additionally, we confirm that linker-specific antibodies can be used for functional testing and enrichment of CAR NK cells, thereby providing a useful research tool to fast-track the development of novel CAR-based therapies.
嵌合抗原受体（CAR）T细胞疗法在癌症治疗中已取得显著成效。目前，市场上有六种已获批的CAR T细胞产品，它们针对B细胞谱系的不同恶性肿瘤。然而，为克服CAR T细胞疗法的局限性，其他免疫细胞正被研究用于基于CAR的细胞疗法。CAR自然杀伤（NK）细胞可作为异基因细胞疗法应用，为自体CAR T细胞提供一种经济、安全且高效的替代方案。为改进CAR研究以及未来对细胞疗法的住院患者监测，一种简单、可靠且通用的CAR检测试剂至关重要。由于大多数现有的CAR包含带有惠特洛或G4S接头位点的单链可变片段（scFv），接头特异性单克隆抗体（mAb）可检测多种CAR。本研究表明，这些接头特异性mAb能够以高特异性和敏感性检测全血中以及患者来源的肿瘤球体中的不同CAR NK细胞，为基于scFv的CAR检测提供了一种有效且几乎通用的替代方法。此外，我们证实接头特异性抗体可用于CAR NK细胞的功能测试和富集，从而为加速新型CAR疗法的开发提供一种有用的研究工具。
