Natural cytotoxicity receptors and their ligands

Natural killer (NK) cells are innate lymphoid cells (ILCs) that participate to the clearance of pathogen‐infected cells and tumour cells. NK cells and subsets of ILCs express the natural cytotoxicity receptors (NCRs) NKp46, NKp44 and NKp30 at their surface. NCRs have been shown to recognize a broad spectrum of ligands ranging from viral‐, parasite‐ and bacterial‐derived ligands to cellular ligands; however, the full identification of NCR ligands remains to be performed and will undoubtedly contribute to a better understanding of NK cell and ILC biology. The March 2014 issue contains a Special Feature on NK cell recognition of unconventional ligands. Natural Killer (NK) cells are bone marrow derived lymphocytes capable of mediating rapid effector responses following pathogen detection in mammals. The name “Natural Killer” derives from the ability of these cells to spontaneously lyse a large range of leukemia cell lines in vitro without prior sensitization. The reviews included in this Special Feature of Immunology and Cell Biology highlight the multifaceted roles of NK cells in detecting unconventional ligands and countering a large range of pathogens and malignancies. Covering a range of topics, including the way adhesion molecules and activating receptors are central to NK cell recognition of their targets, the reviews also highlight some of the challenges that lie ahead in harnessing NK cell function and advancing NK cell immunotherapy strategies to persistent infection, cancer and bone marrow transplantation. Immunology and Cell Biology thanks the coordinator of this Special Feature – Nicholas Huntington – for his planning and input. Further background information on this important topic is available through the accompanying web focus which links to related articles from across Nature Publishing Group.