Magor-6a Flashcards
What is the common feature of tumours that allow them to be killed?
Low or absent cell surface MHC (missing self)
Where do NK cell usu. develop?
thymus
Are NK cells lymphoid or myeloid heritage?
lymphoid
What is NK cell’s hypothesized primary function?
remove stressed or virally infected cells (self)
Difference between classical and non-classical MHC?
Classical MHC molecules bind peptide in a groove while non-classical MHC does not
What anchors the pathogen peptide in the MHC groove?
invariant anchor residues in peptide groove of MHC
What do non-classical MHC-like genes encode?
Proteins that do not bind peptide
Example of what a non-classical MHC would bind
lipid antigens
What type of MHC is CD1 (classical or not)?
non-classical
What does CD1 molecule bind?
lipids derived from bacteria or self
KIR stands for?
Killer Ig-like Receptor
What does lectin normally bind?
carbohydrates
What receptor did humans evolve for their NK cells?
KIRs
Why is KIR an odd lectin?
It binds protein and not lipids
What are the key inhibitory MHC I molecules?
HLA-A, B, C, and E
What would happen to a virus that turns off MHC expression?
It becomes a target for NK cell
What protein would a stressed cell turn on?
nonclassical MHC MIC (A or B)
What does “licensed” mean for an NK cell?
An inhibitory receptor of NK cell has been turned off (verifying)
Allorecognition?
Ability to recognize that another individual of a different species is not self
What do NK cells release when they receive signals from a target cell?
perforin and granzyme B
What is perforin a homologue of in the MAC?
C9
What does Granzyme B do?
initiates apoptosis in target cell
What does the TcR of a NK-T cell recognize?
glycolipids in CD1d
What is CD1d?
nonclassical MHC I
Do NK-T cells form memory cells?
No
What can NK-T cells release?
cytokines
Function of NK-T cells?
- antibacterial innate cell
- regulatory cell
