Restoration of Thymus Function with Bioengineered Thymus Organoids.

The thymus is the primary site for the generation of a diverse repertoire of T cells that are essential to the efficient function of adaptive immunity. Numerous factors varying from aging, chemotherapy, radiation exposure, virus infection, and inflammation contribute to thymus involution, a phenomenon manifested as loss of thymus cellularity, increased stromal fibrosis, and diminished naive T cell output. Rejuvenating thymus function is a challenging task since it has limited regenerative capability and we still do not know how to successfully propagate thymic epithelial cells (TECs), the predominant population of the thymic stromal cells making up the thymic microenvironment. Here, we will discuss recent advances in thymus regeneration and the prospects of applying bioengineered artificial thymus organoids in regenerative medicine and solid organ transplantation.