Impairment of NK Cell Mediated Immune Surveillance Against Acute Myeloid Leukemia

Natural killer (NK) cells are cytotoxic lymphocytes contributing in innate immune responses that recognize and kill virus-infected and tumor cells without prior stimulation. Several clinical trials have indicated that NK cell-based immunotherapy represents a promising antitumor immunotherapeutic approach due to their key role in mediating graft versus leukemic effect against hematological malignancies, particularly acute myeloid leukemia. However, the antitumor activity of NK cells is inhibited as a result to immune-evasion mechanisms developed by malignant cells through alterations in the expression of activating and inhibitory receptors and their ligands, as well as secretion of soluble NK-inhibitory mediators. Until now, the exact molecular mechanisms involved in these alterations are still not defined. Copyright (C) 2022, Turkish Society for Radiation Oncology.