Improving T Cell Expansion with a Soft Touch.

Protein-coated microbeads provide a consistent approach for activating and expanding populations of T cells for immunotherapy, but don’t fully capture the properties of antigen presenting cells. In this report, we enhance T cell expansion by replacing the conventional, rigid bead with a mechanically soft elastomer. Polydimethylsiloxane (PDMS) was prepared in a microbead format and modified with activating antibodies to CD3 and CD28. Three different formulations of PDMS provided an extended proliferative phase in both CD4+-only and mixed CD4+/CD8+ T cell preparations. CD8+ T cells retained cytotoxic function, as measured by a set of biomarkers (perforin production, LAMP2 mobilization, and IFN-γ secretion) and an in vivo assay of targeted cell killing. Notably, PDMS beads presented a nanoscale polymer structure and higher rigidity than associated with conventional bulk material. These data suggest T cells respond to this higher rigidity, indicating an unexpected effect of curing conditions. Together, these studies demonstrate that adopting mechanobiology ideas into the bead platform can provide new tools for T cell-based immunotherapy.

蛋白质包被的微珠为免疫疗法中激活和扩增T细胞群提供了一种稳定的方法，但并不能完全体现抗原呈递细胞的特性。在本报告中，我们通过用一种机械性能柔软的弹性体替代传统的刚性微珠来增强T细胞的扩增。将聚二甲基硅氧烷（PDMS）制成微珠形式，并用针对CD3和CD28的激活抗体进行修饰。三种不同配方的PDMS在仅含CD4⁺以及混合的CD4⁺/CD8⁺ T细胞制剂中都提供了一个延长的增殖阶段。通过一组生物标志物（穿孔素产生、LAMP2动员和干扰素 -γ分泌）以及一项体内靶向细胞杀伤试验测定，CD8⁺ T细胞保留了细胞毒性功能。值得注意的是，PDMS微珠呈现出纳米级聚合物结构，并且比相关的常规块状材料具有更高的刚性。这些数据表明T细胞对这种较高的刚性有反应，这表明固化条件具有意想不到的影响。总之，这些研究表明将力学生物学理念引入微珠平台可为基于T细胞的免疫疗法提供新的工具。