Immunology Lecture 6. Flashcards Preview

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Flashcards in Immunology Lecture 6. Deck (21):
1

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

thymus - the site of TCR gene rearrangements

2

What do T-cells recognize?

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

3

Which MHC does CD8 recognize?

MHCI

4

Which MHC does CD4 recognize?

MHCII

5

What is DiGeorge’s Syndrome?

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

6

What is the importance of “nude” mice?

loss of a transcription factor required for thymus EPITHELIAL differentiation

7

Where do hematopoietic precursors originate?

bone marrow

8

What happens in the cortex of the thymus?

positive selection and lineage commitment

9

What happens in the medulla of the thymus?

negative selection - thymocytes that survive leave via venues

10

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

cells enter here via blood vessels

11

What happens to the thymus with age?

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

12

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

chemokine signaling molecules and sphingosine 1-phosphate receptors

13

Where do mature T cells go?

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

14

CD34

stem-cell surface marker

15

Which chain on the thymocyte rearranges first?

betta chain

16

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

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

17

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

2

18

When is the delta/gamma locus deleted?

when there is rearrangement of the alpha chain

19

What is Aire?

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

20

What is the T cell repertoire?

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

21

What is a regulatory T-cell?

suppressor T cell (esp of CD4 I think)