Infections and auto-immune diseases II

Question 1

What are TSPs?

Answer 1

Thymic seeding progenitor cells

Question 2

What are ETPs?

Answer 2

Early T lineage (thymic) progenitors

Question 3

What are TECs?

Answer 3

Thymic epithelial cells

Question 4

What are RTEs?

Answer 4

Recent thymic immigrants -> youngest subset of peripheral T cells

Question 5

What is a TREC?

Answer 5

T cell receptor excision circle -> small circular DNA fragment formed during TCR rearrangement

Question 6

How do TSPs give rise to ETPs? (2)

Answer 6

1. TSPs arrive in the thymus in small numbers
2. Interaction with TECs

Question 7

For what purpose can you use TRECs?

Answer 7

To assess thymic function

Question 8

BM-derived lymphoid progenitor cells are committed to..? (2)

Answer 8

1. Turning off genes for non- T cell lineage initiating differentiation
2. T cell receptor diversity

Question 9

TCR receptor diversity is due to… (3)

Answer 9

1. Alpha/beta or gamma/delta protein dimers
2. VDJ recombination
3. Junctional diversity

Question 10

What are the four TCR genes that endure genomic rearrangement?

Answer 10

1. TCRa (V-J)
2. TCRb (V-D-J)
3. TCRdelta
4. TCRgamma

Question 11

True or false: During somatic rearrangement, there is huge proliferation and then selective deletion

Answer 11

True

Question 12

Why is the majority of T cells deleted during selection?

Answer 12

Self-reactivity

Question 13

Describe the difference between TCR and MHC diversity

Answer 13

TCR: more or less the same
MHC: polymorphic

Question 14

On which cell types is MHC class I/II presented?

Answer 14

MHC-I: Most nucleated cells
MHC-II: APC