Immune injury[Pathophysiology]

1. IMMUNE INJURY

16. 
Natural killer cells
• NK cells are a part of the
innate immune system and play a major
role in defending the host from both
tumors and virally infected cells. NK cells
distinguish infected cells and tumors from
normal and uninfected cells by
recognizing changes of a surface
molecule called MHC (
major histocompatibility complex)
class I.

17. •NK cells are activated in response to
a family of cytokines called
interferons. Activated NK cells
release cytotoxic (cell-killing)
granules which then destroy the
altered cells.[3] They were named
"natural killer cells" because of the
initial notion that they do not require
prior activation in order to kill cells
which are missing MHC class I.