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.