The impact of T cell exhaustion in hematopoietic stem cell transplantation.

T cell exhaustion is a hallmark of failure to control cancer and chronic infection. In hematological malignancies, T cell exhaustion not only relates to disease progression but also impacts the outcome of hematopoietic stem cell transplantation (HSCT), which may be due to a low graft-versus-leukemia (GVL) effect and a low anti-virus infection capacity. However, a deeper mechanistic understanding of the impact of T cell exhaustion in HSCT remains to be characterized. In this review, we summarize the characteristics of T cell exhaustion, functional alterations in T cells post-transplantation, the role of T cell exhaustion in post-transplant complications, and related therapeutic strategies.