Definition of natural killer cell in US English:

natural killer cell


  • A lymphocyte able to bind to certain tumor cells and virus-infected cells without the stimulation of antigens, and kill them by the insertion of granules containing perforin.

    • ‘These cytokines recruit and activate neutrophils, lymphocytes, macrophages, eosinophils, and natural killer cells at the site of infection.’
    • ‘Children with autism had 20 percent higher concentrations of antibody producing B cells and 40 percent more natural killer cells.’
    • ‘However, these lymphocytes have very few natural killer cells and low antitumor cytolytic activity.’
    • ‘The mouse first goes through a pre-leukemic stage marked by rapidly expanding T cells and natural killer cells, both major components of the immune system.’
    • ‘In some animal studies, it stimulates natural killer cells and monocytes, which the immune system uses to fight off viruses.’
    • ‘In addition, there is heightened expression of surface antigens and activity of natural killer cells.’
    • ‘When we laugh, T cells, natural killer cells and cells that produce antibodies increase in number.’
    • ‘As part of the immune system, natural killer cells normally are present in the blood stream and play a role in defending the body against infection and against some cancers.’
    • ‘Animal studies indicate that it enhances the immune system by stimulating natural killer cells and T cells, and by decreasing cancerous tumor's size.’
    • ‘Researchers suggested that this is a result of an inability to replenish activated natural killer cells.’