[Veto T cells enhance engraftment allogeneic hematopoietic stem cells]

Veto activity was defined as the capacity of specifically downregulating cytotoxic T-precursor cell (CTL-p) directed against antigens of the veto cells themselves but not against third-party antigens. Many studies have shown that the most potent veto cells are CD8(+) cytotoxic T lymphocytes (CD8(+)CTLs). Effectively, CD8(+)CTLs of donor origin can facilitate engraftment of donor's stem cells by eliminating host-alloreactive T lymphocytes. In this article, effect mechanisms, depletion of GVH ex vivo, application in vivo, synergistic enhancement with rapamycin and regulatory T cells, and anti-tumor effect in the hematopoietic stem cell transplantation are summarized.