A question of persistence: Langerhans cells and graft‐versus‐host disease

Langerhans cells ( LC s) have been scrutinized many times in studies of the pathogenesis of graft‐versus‐host disease ( GVHD ). As migratory dendritic cells, LC s are capable of direct antigen presentation to cytotoxic T cells. Their self‐renewal capacity has led to speculation that persistent recipient LC s could provide a continuous source of host antigen to donor T cells infused during hematopoietic stem cell transplantation ( HSCT ). In this issue of Experimental Dermatology, a new study examines at the relationship between recipient LC s and chronic GVHD .