Function of hassals corpuscles of thymus gland?

Hassall's corpuscles are present in the medulla of thymus gland. The function of Hassall's corpuscles is still unclear. However, it is thought that these cells are the source of cytokine TSLP . It has been observed in invitro conditions that TSLP directs the maturation of dendritic cells. It is also thought to increase the ability of dendritic cells to change naive thymocytes into regulatory T cell lineage.