Beck Carole, Casey Nicholas Paul, Persiconi Irene, Moharrami Neda Nejati, Sike Adam, Jin Yixin, Kyte Jon Amund
Department of Cancer Immunology, Institute for Cancer Research, Oslo University Hospital, 0424 Oslo, Norway.
Department of Clinical Cancer Research, Oslo University Hospital, 0424 Oslo, Norway.
Biomedicines. 2023 Feb 4;11(2):459. doi: 10.3390/biomedicines11020459.
Therapy employing T cells modified with chimeric antigen receptors (CARs) is effective in hematological malignancies but not yet in solid cancers. CAR T cell activity in solid tumors is limited by immunosuppressive factors, including transforming growth factor β (TGFβ). Here, we describe the development of a switch receptor (SwR), in which the extracellular domains of the TGFβ receptor are fused to the intracellular domains from the IL-2/15 receptor. We evaluated the SwR in tandem with two variants of a CAR that we have developed against STEAP1, a protein highly expressed in prostate cancer. The SwR-CAR T cell activity was assessed against a panel of STEAP1 prostate cancer cell lines with or without over-expression of TGFβ, or with added TGFβ, by use of flow cytometry cytokine and killing assays, Luminex cytokine profiling, cell counts, and flow cytometry phenotyping. The results showed that the SwR-CAR constructs improved the functionality of CAR T cells in TGFβ-rich environments, as measured by T cell proliferation and survival, cytokine response, and cytotoxicity. In assays with four repeated target-cell stimulations, the SwR-CAR T cells developed an activated effector memory phenotype with retained STEAP1-specific activity. In conclusion, the SwR confers CAR T cells with potent and durable in vitro functionality in TGFβ-rich environments. The SwR may be used as an add-on construct for CAR T cells or other forms of adoptive cell therapy.
采用嵌合抗原受体（CAR）修饰的T细胞进行的治疗在血液系统恶性肿瘤中有效，但在实体癌中尚未取得成效。实体瘤中CAR T细胞的活性受到免疫抑制因子的限制，包括转化生长因子β（TGFβ）。在此，我们描述了一种开关受体（SwR）的研发，其中TGFβ受体的胞外结构域与IL-2/15受体的胞内结构域融合。我们将SwR与我们研发的针对前列腺癌中高表达的一种蛋白质STEAP1的CAR的两种变体串联进行评估。通过流式细胞术细胞因子和杀伤试验、Luminex细胞因子分析、细胞计数和流式细胞术表型分析，针对一组STEAP1前列腺癌细胞系评估SwR-CAR T细胞活性，这些细胞系有或没有TGFβ过表达，或添加了TGFβ。结果表明，通过T细胞增殖和存活、细胞因子反应及细胞毒性来衡量，SwR-CAR构建体在富含TGFβ的环境中改善了CAR T细胞的功能。在进行四次重复靶细胞刺激的试验中，SwR-CAR T细胞形成了具有保留的STEAP1特异性活性的活化效应记忆表型。总之，SwR在富含TGFβ的环境中赋予CAR T细胞强大且持久的体外功能。SwR可用作CAR T细胞或其他形式过继性细胞治疗的附加构建体。
