Department of Materials Science and Engineering, Monash Institute of Medical Engineering, Monash University, Wellington Road, Clayton, Melbourne 3800, Australia.
Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Wellington Road, Clayton, Melbourne 3800, Australia.
ACS Biomater Sci Eng. 2020 Apr 13;6(4):2198-2208. doi: 10.1021/acsbiomaterials.9b01610. Epub 2020 Mar 12.
T cells are predominantly produced by the thymus and play a significant role in maintaining our adaptive immune system. Physiological involution of the thymus occurs gradually with age, compromising naive T cell output, which can have severe clinical complications. Also, T cells are utilized as therapeutic agents in cancer immunotherapies. Therefore, there is an increasing need for strategies aimed at generating naive T cells. The majority of in vitro T cell generation studies are performed in two-dimensional (2D) cultures, which ignore the physiological thymic microenvironment and are not scalable; therefore, we applied a new three-dimensional (3D) approach. Here, we use a gelatin-based 3D microgel system for T lineage induction by co-culturing OP9-DL4 cells and mouse fetal-liver-derived hematopoietic stem cells (HSCs). Flow cytometric analysis revealed that microgel co-cultures supported T lineage induction similar to 2D cultures while providing a 3D environment. We also encapsulated mouse embryonic thymic epithelial cells (TECs) within the microgels to provide a defined 3D culture platform. The microgel system supported TEC maintenance and retained their phenotype. Together, these data show that our microgel system has the capacity for TEC maintenance and induction of in vitro T lineage differentiation with potential for scalability.
T 细胞主要由胸腺产生，在维持我们的适应性免疫系统中发挥重要作用。胸腺的生理性退化随着年龄的增长逐渐发生，影响幼稚 T 细胞的产生，这可能会导致严重的临床并发症。此外，T 细胞也被用作癌症免疫疗法中的治疗剂。因此，人们越来越需要寻找产生幼稚 T 细胞的策略。大多数体外 T 细胞生成研究都是在二维（2D）培养中进行的，这种方法忽略了生理胸腺微环境，并且不可扩展；因此，我们采用了一种新的三维（3D）方法。在这里，我们使用基于明胶的 3D 微凝胶系统，通过共培养 OP9-DL4 细胞和小鼠胎肝来源的造血干细胞（HSCs）来诱导 T 细胞谱系。流式细胞术分析显示，微凝胶共培养支持类似于 2D 培养的 T 细胞谱系诱导，同时提供了 3D 环境。我们还将小鼠胚胎胸腺上皮细胞（TECs）包封在微凝胶中，以提供一个明确的 3D 培养平台。微凝胶系统支持 TEC 的维持，并保留其表型。总之，这些数据表明，我们的微凝胶系统具有维持 TEC 和诱导体外 T 细胞谱系分化的能力，具有潜在的可扩展性。
