natural killer cell
Meaning of natural killer cell: Natural killer cells are innate immune cells that destroy virus infected and abnormal cells without needing prior exposure to a specific target.
Definition of natural killer cell
A natural killer cell is a type of white blood cell that forms part of the innate immune system, the body's rapid, nonspecific first line of defense. Unlike T cells, natural killer cells can recognize and destroy virus infected or abnormal cells without needing prior exposure or sensitization to a specific target.
Natural killer cells contain granules filled with proteins that can trigger a targeted cell to break apart once contact is made. They are particularly important in detecting cells that have lost or altered the surface markers a healthy cell normally displays, a change that can occur in cells infected by certain viruses or in tumor cells.
Natural killer cells work alongside other components of the immune system, including antibodies and T cells, but their ability to act without prior sensitization allows them to respond quickly, often before a more targeted immune response has fully developed.
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Used in a sentence
Laboratory testing measured the patient's natural killer cell activity as part of an immune function evaluation.
Good to know
Natural killer cells act without needing to recognize a specific previously encountered target, distinguishing them from T cells, which require prior exposure and sensitization to respond to a particular threat.