Natural Born Killers: NK Cells And CD8+ T Lymphocytes Flashcards
What are cytotoxic T cells controlled by?
T cell receptor recognition with CD8 acting as a coreceptor
Which immune response are cytotoxic T cells involved in?
Adaptive immune response
Which immune response are natural killer cells involved in?
Innate immune response
What are NK cells controlled by?
A balance of signals between different activating and inhibitory receptors on their surface
Which of NK cells and cytotoxic T cells are more specific?
Cytotoxic T cells
Why do we need more that one type of cytotoxic lymphocyte?
Combat infection in the time before a T cell response develops
Provide an alternative system when a tumour or infected cell evades cytotoxic T cell responses
To provide an additional mechanism for killing infected targets via antibody recognition
What is low NK cell activity correlated with?
Severe disseminating herpesvirus infections
Where are MHC class 1s found?
All uncleared cells
What are MHC class 1s made up of?
Two polypeptides that are non-covalently bound
What are the three gene loci for HLAs?
A, B and C
Where are MHC polymorphisms found?
In the upper peptide-binding part of the MHC protein
What do TCRs recognise?
MHC protein itself
Antigenic peptide presented by MHC protein
What allows CD8 and TCR to bind to MHC-1 at the same time?
Distant binding sites
What does CD8 act as for MHC-1?
Coreceptor
What does TCR bind to (specifically)?
Alpha1alpha2 domains
