Ingham-8: T Cell Development I

Question 1

Where do T cell precursors originate?

Answer 1

bone marrow

Question 2

Where do T cells develop?

Answer 2

thymus

Question 3

Is TCR needed during early T cell development?

Answer 3

NO

Question 4

What is the ordered progression of TCR rearrangement?

Answer 4

• beta chain before alpha chain

Question 5

What is beta selection?

Answer 5

selection for a beta chain that can bind pre-Talpha and form the pre-TCR

Question 6

Define positive selection

Answer 6

selection for cells whose TCRs can interact with self-MHC/self-peptide with intermediate affinity

Question 7

Define negative selection

Answer 7

selection against cells whose TCRs that strongly interact with self-MHC/self-peptides

Question 8

Define lineage commitment

Answer 8

thymocytes become CD4+ or CD8+ cells

Question 9

Define Double Negative (DN) cells

Answer 9

no CD4 nor CD8 expression

Question 10

What stage does T cell lineage commitment occur?

Answer 10

DN2

Question 11

What stage does the pre-TCR form?

Answer 11

DN3

Question 12

T cell lineage commitment is aided by which factors?

Answer 12

Notch1 and GATA-3

Question 13

What stage does the beta chain start to rearrange?

Answer 13

DN2

Question 14

What process decides whether the T cell will become an alpha/beta or gamma/delta T cell?

Answer 14

whichever rearrangement happens first (beta or gamma, delta), that will be the T cell it makes

Question 15

What are the components of pre-TCR?

Answer 15

• beta chain
• pre-Talpha
• CD3 (signalling component)

Question 16

Does pre-TCR need a ligand for signalling to occur?

Answer 16

unclear (maybe not)

Question 17

Functions of cTECs

Answer 17

help with positive and negative selection

Question 18

4 fates of DP thymocyte

Answer 18

• death by neglect
• positive selection
• agonist selection
• negative selection