Immunology Lecture 6.

Question 1

What is the major site of T-cell development? which part specifically?

Answer 1

thymus - the site of TCR gene rearrangements

Question 2

What do T-cells recognize?

Answer 2

Peptides derived from self or foreign antigens ONLY when bound to MHC

Question 3

Which MHC does CD8 recognize?

Answer 3

MHCI

Question 4

Which MHC does CD4 recognize?

Answer 4

MHCII

Question 5

What is DiGeorge’s Syndrome?

Answer 5

lack of thymus/thymic function leading to human T cell immunodeficiency

Question 6

What is the importance of “nude” mice?

Answer 6

loss of a transcription factor required for thymus EPITHELIAL differentiation

Question 7

Where do hematopoietic precursors originate?

Answer 7

bone marrow

Question 8

What happens in the cortex of the thymus?

Answer 8

positive selection and lineage commitment

Question 9

What happens in the medulla of the thymus?

Answer 9

negative selection - thymocytes that survive leave via venues

Question 10

What happens at the cortco-medullary junction of the thymus?

Answer 10

cells enter here via blood vessels

Question 11

What happens to the thymus with age?

Answer 11

decline of function although you don’t become immune-deficient

Question 12

How to T-cell precursors travel to the thymus from the bone marrow?

Answer 12

chemokine signaling molecules and sphingosine 1-phosphate receptors

Question 13

Where do mature T cells go?

Answer 13

secondary lymphoid tissue where they wait to fight infection (spleen and lymph nodes)

Question 14

CD34

Answer 14

stem-cell surface marker

Question 15

Which chain on the thymocyte rearranges first?

Answer 15

betta chain

Question 16

How does the cell know it’s made a successful Beta chain?

Answer 16

pre T-cell receptor (heterodimer to superdimer to pre T-cell receptor

Question 17

How many attempts to achieve a productive rearrangement of the Beta chain locus?

Answer 17

2

Question 18

When is the delta/gamma locus deleted?

Answer 18

when there is rearrangement of the alpha chain

Question 19

What is Aire?

Answer 19

transcription factor - promiscuous transcription of genes that are not normally expressed in the thymus - ligands that are created to avoid autoimmune disease

Question 20

What is the T cell repertoire?

Answer 20

sum of all the specificities of the mature T cells produced by the thymus

Question 21

What is a regulatory T-cell?

Answer 21

suppressor T cell (esp of CD4 I think)