Human Intestinal Allografts Contain Functional Hematopoietic Stem and Progenitor Cells that Are Maintained by a Circulating Pool

？ Human intestine contains hematopoietic stem cells and multiple types of progenitors ？ Donor graft HSPCs contribute to multilineage blood chimerism in the recipient ？ Long-term circulating donor T cells are tolerant to the recipient but functional ？ Intestinal HSPCs undergo replacement by the recipient from a circulating poo