Recapitulation of Thymic Function by Tissue Engineering Strategies

The thymus is responsible for the development and selection of T
lymphocytes, which in turn also participate in the maturation of thymic
epithelial cells. These events occur through the close interactions between
hematopoietic stem cells and developing thymocytes with the thymic stromal
cells within an intricate 3D network. The complex thymic microenvironment
and function, and the current therapies to induce thymic regeneration or to
overcome the lack of a functional thymus are herein reviewed. The
recapitulation of the thymic function using tissue engineering strategies has
been explored as a way to control the body’s tolerance to external grafts and
to generate ex vivo T cells for transplantation. In this review, the main
advances in the thymus tissue engineering field are disclosed, including both
scaffold- and cell-based strategies. In light of the current gaps and limitations
of the developed systems, the design of novel biomaterials for this purpose
with unique features is also discussed.