Clinical studies using autologous CAR T cells have achieved spectacular remissions in refractory CD19+ B cell leukaemia, however some of the patient treatments with CAR T cells failed. Beside the heterogeneity of leukaemia, the distribution and senescence of the autologous cells from heavily pretreated patients might be further reasons for this. We performed six consecutive large-scale manufacturing processes for CD20 CAR T cells from healthy donor leukapheresis using the automated CliniMACS Prodigy® platform. Starting with a CD4/CD8-positive selection, a high purity of a median of 97% T cells with a median 65-fold cell expansion was achieved. Interestingly, the transduction rate was significantly higher for CD4+ compared to CD8+ T cells and reached in a median of 23%. CD20 CAR T cells showed a good specific IFN-γ secretion after cocultivation with CD20+ target cells which correlated with good cytotoxic activity. Most importantly, 3 out of 5 CAR T cell products showed an increase in telomere length during the manufacturing process, while telomere length remained consistent in one and decreased in another process. In conclusion, this shows for the first time that beside heterogeneity among healthy donors, CAR T cell products also differ regarding cell senescence, even for cells manufactured in a standardised automated process.

中文翻译：

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使用自动化 CliniMACS Prodigy® 平台制造的 CD4/CD8 选择的 CD20 CAR T 细胞的功能和细胞衰老

使用自体 CAR T 细胞的临床研究在难治性 CD19+ B 细胞白血病中取得了惊人的缓解，但是一些使用 CAR T 细胞的患者治疗失败了。除了白血病的异质性之外，来自大量预处理患者的自体细胞的分布和衰老可能是造成这种情况的进一步原因。我们使用自动化的 CliniMACS Prodigy® 平台对来自健康供体白细胞去除术的 CD20 CAR T 细胞进行了六次连续的大规模制造工艺。从 CD4/CD8 阳性选择开始，实现了中位数为 97% T 细胞的高纯度和中位数 65 倍的细胞扩增。有趣的是，CD4+ 的转导率明显高于 CD8+ T 细胞，中位数达到 23%。CD20 CAR T 细胞在与 CD20+ 靶细胞共培养后显示出良好的特异性 IFN-γ 分泌，这与良好的细胞毒活性相关。最重要的是，5 种 CAR T 细胞产品中有 3 种在制造过程中显示端粒长度增加，而端粒长度在一个过程中保持一致，而在另一个过程中则减少。总之，这首次表明，除了健康供体之间的异质性外，CAR T 细胞产品在细胞衰老方面也存在差异，即使对于在标准化自动化过程中制造的细胞也是如此。