natural killer cell(redirected from Killer cells, natural)
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natural killer cell
A lymphocyte that is activated by double-stranded RNA or lymphokines and fights off viral infections and tumors without evident antigenic specificity. Also called NK cell.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.
natural killer cellAbbreviation: NK cell
A large granular lymphocyte – a defensive cell of innate immunity – that bonds to cells and lyses them by releasing cytotoxins. Natural killer cells are null cells, lymphocytes that do not have B cell or T cell surface markers, and they can be activated without previous antigen exposure. NK cells destroy cells infected with viruses and some types of tumor cells in cultures. They also secrete gamma interferon (INF?), tumor necrosis factor alpha (TNFa), and granulocyte-macrophage colony-stimulating factor (GMCSF), enhancing the effect of T lymphocytes.Synonym: killer cell
See also: cell
Medical Dictionary, © 2009 Farlex and Partners
Natural killer (NK) cell
A lymphocyte that acts as a primary immune defense against infection.
Mentioned in: Chronic Fatigue Syndrome
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.