Ingham-8: T Cell Development I Flashcards
Where do T cell precursors originate?
bone marrow
Where do T cells develop?
thymus
Is TCR needed during early T cell development?
NO
What is the ordered progression of TCR rearrangement?
- beta chain before alpha chain
What is beta selection?
selection for a beta chain that can bind pre-Talpha and form the pre-TCR
Define positive selection
selection for cells whose TCRs can interact with self-MHC/self-peptide with intermediate affinity
Define negative selection
selection against cells whose TCRs that strongly interact with self-MHC/self-peptides
Define lineage commitment
thymocytes become CD4+ or CD8+ cells
Define Double Negative (DN) cells
no CD4 nor CD8 expression
What stage does T cell lineage commitment occur?
DN2
What stage does the pre-TCR form?
DN3
T cell lineage commitment is aided by which factors?
Notch1 and GATA-3
What stage does the beta chain start to rearrange?
DN2
What process decides whether the T cell will become an alpha/beta or gamma/delta T cell?
whichever rearrangement happens first (beta or gamma, delta), that will be the T cell it makes
What are the components of pre-TCR?
- beta chain
- pre-Talpha
- CD3 (signalling component)
Does pre-TCR need a ligand for signalling to occur?
unclear (maybe not)
Functions of cTECs
help with positive and negative selection
4 fates of DP thymocyte
- death by neglect
- positive selection
- agonist selection
- negative selection
