NK cells Flashcards
NK cells originate from
bone marrow
how long do NK cells live for
about one week
Where are NK cells found
- blood
- spleen
- liver
when do NK cell migrate to tissues in large numbers
-only when an inflammatory reaction is underway
what type of receptors does the NK cells not posses
NK cells do not posses receptors generated through gene segment rearrangement
-(i.e. no receptors such as TCR or BCR)
what three types of cell trafficking receptors are on NK cells
- Chemotactic receptors
- Cytokine receptors
- Adhesion receptors
NK cells aka
Large granular lymphocytes (LGL)
why are NK cells referred to as LGL
-because morphologically thy resemble large lymphocytes and contain granules
how are NK cells ID in vitro in mice and humans
-by the expression of DD56, CD16, and lack of CD3
how are NK cells ID in vitro in pigs
there is no exclusive marker but CD2+/CD8+/CD3- are used with (NKp46)
how are NK cells ID in vitro in cattle
-CD335 (NKp46) has recently been reported to be expressed on bovine NK cells (horses too)
Role of NK cells in innate immunity
- Kill abnormal cells
- production of cytokine and chemokines
Following activation in vitro with cytokines such as _____ and _____ NK cells become _____________
- IL-2
- IFNy
- Lymphokine activated killer cells (LAK)
what cytokine and chemokine production are NK cells responsible for
-IFNy
-TNFalpha
-IL-17
-IL-22
-MIP-1alpha
MIP-1beta
what are abnormal cells
-cells that have become stressed by any means, infected, or a transformed cell (tumor)
How do NK cells recognize abnormal cells
-cells that are stressed, infected or transformed alter expression of certain cell surface markers
what do all normal cell express on their surface
-MHC class 1-Major histocompatibility complex class 1
how is the expression of MHC 1 affected in abnormal cells
the expression of MHC 1 is suppressed in abnormal cells
what surface markers are highly expressed on cells that are abnormal
- MHC 1 chain-related A (MICA)
- MICB
- Rae-1
- H60
what 2 types of receptors are expressed on NK cells
- Activating receptors
- Inhibitory receptors
how is the activation of NK cells regulated
-by a balance between signals from activating and inhibitory receptors
what will a high level of activating signals lead the NK cell to do
kill the target cell
what is the result of a strong inhibitory signal on the NK cell
preserves the target cell
what is an example of a strong inhibitory signal for NK cells
-Normal MHC 1 expression and absence of stress markers