HANGING IN THE BALANCE

Potential mechanism for the protective effect of haploidentical bone marrow transplantation in acute myeloid leukemia. A subpopulation of donor derived NK cells do not express an inhibitory receptor for recipient HLA class I. These NK cells are able to lyse recipient T and NK cells (preventing rejection), recipient dendritic cells (preventing rejection), and recipient leukemic cells (preventing relapse). Conversely, these NK cells do not seem to attack somatic tissues.