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
when both signals for activation and inhibition are presented to the NK cell which signal is dominant
the dominant signal is the inhibitory signal
NK cell receptors are used to
recognize normal or abnormal cells
what are the two classes of receptors
- immunoglobulin-like receptors
- leptin like receptors
how does the class of receptors varry
the class of receptors vary based on the species
in Human/cattle/cats/dogs/pigs NK cell receptors that recognize the MHC 1 molecule belong to the
- Killer cell immunoglobulin-like receptor family
- AKA KIRs (or CD158)
In mice/rats/horse NK cells that recognize MHC 1 are called
- Killer cell lectin like receptors
- AKA KLRs
what type of transmembrane protein are KIRs
Type 1 transmembrane protein