OBJECTIVE: NK cells are important cells of the immune system. They are ultimately derived from pluripotent hematopoietic stem cells. NK cell @entity137 and other functions are tightly regulated by numerous activating and inhibitory receptors including newly discovered receptors that selectively recognize major histocompatibility complex class I alleles. Based on their defining function of spontaneous @entity137 without prior immunization, NK cells have been thought to play a critical role in immune surveillance and @entity5 therapy. However, new insights into NK cell biology have suggested major roles for NK cells in @entity281 control and uterine function. The purpose of this review is to provide an update on NK cell function, ontogeny, and biology in order to better understand the role of NK cells in health and disease. DATA SOURCES: In the Medline database, the major subject heading "Natural Killer Cells" was introduced in 1983, identifying 16,848 citations as of December 31, 2000. Since 1986, there have been approximately 1000 citations per year under this subject heading. In this database, 68% of manuscripts are limited to @entity1 NK cells; 40% of citations cross with the major sub-heading of @entity137 , 40% with cytokines, 36% with @entity5 , 5% with antibody-dependent cellular @entity137 , 2.8% with pregnancy, and 1.3% with @entity281 . Of references from the year 2000-2001, 46 were selected to combine with contributions from earlier literature. CONCLUSIONS: NK cells should no longer be thought of as direct cytotoxic killers alone as they clearly serve a critical role in cytokine production which may be important to control @entity5 , @entity281 , and fetal implantation. Understanding mechanisms of NK cell functions may lead to novel therapeutic strategies for the treatment of @entity1 disease.

The biology of natural killer cells in XXXX , @entity281 , and pregnancy.

@entity5 :: ('MESH:D009369', 'Disease') :: ['cancer', 'neoplasm'] @entity281 :: ('MESH:D007239', 'Disease') :: ['infection'] @entity1 :: ('9606', 'Species') :: ['human'] @entity137 :: ('MESH:D064420', 'Disease') :: ['cytotoxicity']
@entity5 :: (MESH:D009369,Disease) :: ['cancer']
