Specialized microenvironments within the thymus are comprised of unique cell types with distinct roles in directing the development of a diverse, functional, and self-tolerant T cell repertoire. As they differentiate, thymocytes transit through a number of developmental intermediates that are associated with unique localization and migration patterns. This transition is associated with dramatic changes in cell surface proteins needed to direct the maturing thymocytes within the thymus.

This review discusses the dynamic changes in behavior that occur throughout thymocyte development, and provides an overview of the cell-intrinsic and extrinsic mechanisms that regulate human thymocyte migration.