T-Cell Differentiation from Hematopoietic Progenitor Cells Using 3D Thymic-like Hydrogels

Chimeric antigen receptor T-cell immunotherapy represents a breakthrough in treating specific cancer types. However, a critical limitation in its application is the current shortage of donor cells. Attempts to recreate the thymic microenvironment, facilitating the differentiation of therapeutic T-cells from stem cells, hold significant promise for clinical advancements. Nonetheless, replicating crucial elements of T-cell development—dependent on the thymus’s three-dimensional (3D) architecture and its complex matrix composition, including stiffness and intricate cell–cell and cell–matrix interactions—remains unattainable with existing thymic models. To address this, we engineered biomaterials integrated with key thymic components such as Delta-like 4, vascular cell adhesion molecule 1, and proteins derived from collagen. These components are instrumental in directing T-cell development while inhibiting alternative lineage differentiation. Our work led to the identification of a hydrogel formulation that results in the production of both CD4+CD8b+ progenitor (Pro) T-cells and mature, functional CD3+CD8b+ T-cells. The resultant T-cells are not only functional, with the capability for cytokine production, but also mark the establishment of the first hydrogel-based platform for producing T-cells from induced pluripotent stem cell-derived hematopoietic stem and Pro cells. This system uniquely supports essential cell-to-cell and cell-to-extracellular matrix interactions within a 3D context.