What are natural killer cells?
Q: What are natural killer cells?
A: Natural killer cells (or NK cells) are a type of lymphocyte critical to the innate immune system.
Q: What is the function of natural killer cells?
A: NK cells provide a rapid response to cells infected by viruses, or to bacterial cells. NK cells also respond to tumour formation.
Q: When does the response of natural killer cells happen after infection?
A: The response of natural killer cells happens about 3 days after infection.
Q: What makes natural killer cells unique?
A: Natural killer cells are unique because they have the ability to recognise stressed cells in the absence of antibodies and major histocompatibility complex (MHC).
Q: How does the unique ability of natural killer cells allow for a faster immune reaction?
A: The unique ability of natural killer cells to recognise stressed cells in the absence of antibodies and major histocompatibility complex (MHC) allows for a much faster immune reaction.
Q: What was observed in early experiments in cancer patients and animals?
A: In early experiments in cancer patients and animals, investigators found what was called a "natural" reactivity, which means that a certain population of cells seemed to be able to kill tumour cells without being sensitized to them.
Q: When was the existence of a separate line of cells with natural killing ability suggested?
A: By 1973, 'natural killing' activity was established across a wide variety of species, and the existence of a separate line of cells with this ability was suggested.
