Chapter 7 - T cell development (Exam 3)

Question 1

Two lineages that develop in the thymus

Answer 1

a:b (majority)
g:d (minority)

Question 2

in the cortex of the thymus there are

Answer 2

immature lymphocytes

Question 3

in the medulla of the thymus there are

Answer 3

mature lymphocytes

Question 4

Digeorge’s syndrome

Answer 4

thymus does not develop, still have B cells
susceptible to infections
similar to SCID

Question 5

thymus is ____________ at birth

Answer 5

fully developed

Question 6

involution

Answer 6

T cell producing tissue is replaced by fatty tissue as you age

Question 7

does involution/thymectomy impair T cell immunity?

Answer 7

No

Question 8

mature T cells in the periphery are

Answer 8

long lived and self renewing

Question 9

double negative lymphocytes

Answer 9

don’t have CD4 or CD8

Question 10

Notch 1

Answer 10

drives T cell differentiation

Question 11

what cytokine is crucial for development? who is it secreted by?

Answer 11

IL-7

stromal epithelial cells

Question 12

Notch 1 is similar to _________ in B cells

Answer 12

Pax5

Question 13

gamma delta T cell receptor has _________ diversity than alpha beta T cell receptor

Answer 13

less

Question 14

unlike ab T cell receptor, gd T cell receptor can bind

Answer 14

peptide without MHC

Question 15

gene rearrangements in alpha and beta chains

Answer 15

alpha - V-J rearrangements
beta - DJ, VDJ rearrangements

Question 16

gene rearrangements in gamma and delta chains

Answer 16

gamma: VJ rearrangements
delta: DJ, VDJ rearrangements

Question 17

Step 1 of competition of gene rearrangements in T cells

Answer 17

g,d chains rearrange vs b chain rearranges

whoever finishes 1st continues

Question 18

only about _________ of all thymocytes do not undergo apoptosis

Answer 18

2%

Question 19

first checkpoint of T cell development

Answer 19

assembly of pre-TCR

ensures allelic exclusion has occurred

Question 20

after the beta chain rearranges and the pre-TCR binds, functional B chain expresses

Answer 20

CD4 and CD8

Question 21

double positive thymocyte

Answer 21

expresses both CD4 and CD8

Question 22

pTa

Answer 22

surrogate light chain in the Pre-T-cell receptor

Question 23

pre T cells

Answer 23

productively rearranged B chains –> temporarily express RAG –> allelic exclusion –>
induced to proliferate –> express CD4 and CD8 –> stop proliferating

Question 24

step 2 competition of T cell development (if beta chain rearrangement occurs)

Answer 24

gd rearrangement vs alpha rearrangement

Question 25

committed alpha beta T cell occurs after

Answer 25

both the beta chain and alpha chain rearrangement occur

Question 26

2nd checkpoint in T cell development

Answer 26

test if alpha chain binds beta chain and assembles TCR

Question 27

early T cell development in the thymus results in

Answer 27

double positive thymocytes and a functional TCR

Question 28

Th-Pok

Answer 28

transcription factor
pushes DP cells to CD4 only

Question 29

positive selection in T cells

Answer 29

select for cells that bind self MHC

Question 30

negative selection in T cells

Answer 30

select against cells that bind self peptide

Question 31

positive selection of T cells occurs in ___________ cells only

why?

Answer 31

alpha beta

gamma delta does not recognize peptide/MHC complex

Question 32

only _________ of DP thymocytes bind to self MHC

Answer 32

2%

Question 33

when the receptor binds to self peptide/MHC class I, which T cell forms?

when it binds to self peptide/MHC class II?

Answer 33

CD8

CD4

Question 34

AIRE

Answer 34

autoimmune regulator
helps with negative selection
TF that allows thyme antigen presenting cells to express certain self antigens expressed in non-thymus tissue

Question 35

what happens when there is a deficiency in AIRE?

Answer 35

T cells attack organs due to recognizing self peptides

Question 36

central tolerance

Answer 36

inside thymus

Question 37

peripheral tolerance

Answer 37

outside thymus

Question 38

two methods of peripheral tolerance

Answer 38

recognition of self antigen will inactivate auto reactive T cell

Treg suppresses auto reactive T cells

Question 39

Treg (supressor T cell)

Answer 39

suppresses dendritic cell activation of T cells

suppresses T cells by releasing cytokines

Question 40

self reactive Treg cells are present in

Answer 40

circulation of all people

Question 41

2 characteristics of Treg

Answer 41

CD25
FoxP3

Question 42

final phase of T cell differentiation

Answer 42

T cell binds to antigen in secondary lymphoid tissue

Question 43

T cell leaves thymus, It is ________ but still __________

Answer 43

mature

naive

Question 44

when T cell binds specific antigen it then

Answer 44

divides and differentiates into effector cell