Immunology 8

Question 1

Unlike B-cells, T-cells undergo very little maturation in the ?

Answer 1

bone marrow

Question 1

After stem cells “choose” to become lymphoid progenitors, those progenitors divide under the influence of

Answer 1

IL-7

Question 2

T cells need to travel to the ? to develop function T-cell receptors (TCR)

Answer 2

thymus

Question 3

where is the thymus located

Answer 3

superior to the heart and anterior to the great vessels

Question 4

thymus is largest or smallest prior to puberty?

Answer 4

largest

Question 5

the thymus is divided into ?

Answer 5

cortex and medulla

Question 6

what does double negative mean?

Answer 6

the T-cell precursors do not express CD8 or CD4

Question 7

when DN cells commit to a T-cell lineagethey are known as ?, these cells are mostly found in the ?

Answer 7

DN3 cells
cortex of the thymus

Question 8

DN cells first rearrange the ? of the TCR, If this is done correctly, then proliferation continues known as ?. If the beta chain is useless, the ?

Answer 8

beta chain
DN4
cell dies

Question 9

After the beta chain is rearranged and done correctly, the ? of the TCR is then shuffled.

Answer 9

alpha chain

Question 10

After both TCR chains have been recombined, the developing T-cell expresses both CD4 AND CD8 -> ?

Answer 10

double positive (DP)

Question 11

DP cells will recombined with TCRs sample…

Answer 11

thymic epithelial cells HLA

Question 12

If DP cells has very low affinity interactions to thymic epithelial cells HLA ->

Answer 12

death of the DP T-cell

Question 13

If DP cells has medium-low affinity interactions to thymic epithelial cells HLA ->

Answer 13

survival of the DP T-cell

Question 14

If DP cells has very high affinity interactions to thymic epithelial cells HLA ->

Answer 14

death of the DP T-cell

Question 15

DP cells that have been positively selected and have survived negative selection then ?

Answer 15

“make a choice”

Question 16

The DP cell with its useful TCR will ? to see if the CD8 or CD4 co-receptor interacts better with the medullary TECs

Answer 16

“test”

Question 17

ultimately, at the end of T cell development, T cells express only ? or ?

Answer 17

CD4 or CD8

Question 18

what is the rationale for positive selection when TCR has a “low-medium” affinity for a thymic epithelial cell’s (TEC) HLA bound to self-antigen, it is allowed to survive

Answer 18

the TCR is capable of interacting with an HLA molecule, but is unlikely to recognize self

Question 19

what is the rationale for negative selection when TCR has a “high” affinity for a thymic epithelial cell’s (TEC) HLA bound to self-antigen, it is allowed to survive

Answer 19

this is T cell with a TCR that recognizes self – it should not be allowed to survive

Question 20

what is a transcription factor-like protein that binds with a wide range of other transcription factors and activates them for central tolerance

Answer 20

AIRE

Question 21

CD4+ Treg cells polarized by ?

Answer 21

interaction with an APC and presence of high circulating levels of TGF-B

Question 22

what is expressed by helper T-cells, binds to B7 with higher affinity than CD28

Answer 22

CTLA-4

Question 23

Binding of CTLA-4 to B7 (CD80/CD86) molecules on APCs usually renders the CD4+ cell ?

Answer 23

anergic

Question 24

As well, T-reg cells often express CTLA-4 and can shut down ? expression on the APC.Net result – if you knock out CTLA-4 in a mouse, it always gets very ?

Answer 24

CD80/86
severe autoimmune disease

Question 25

CTLA-4 binds to CD80/86 ->

Answer 25

downregulation of APC presenting antigen

Question 26

TREG can inhibit APCs by signaling through the CD80/CD86 (B7) receptor. This engagement results in :

Answer 26

• Decreased expression of CD80/86
• Activation of indoleamine-2,3-dioxygenase (IDO)
• Changes in transcription leading to decreased expression of IL-6 and TNF-alpha

Question 27

Treg cells also express high levels of ?-> ? IL-2 and preventing it from activating an effector cell

Answer 27

IL-2 receptor
“soaking up”

Question 28

When the barrier is healthy, with no tissue damage, then ? predominates in the mucosa

Answer 28

TGF-beta

Question 29

TGF-beta and retinoic acid promotes class-switching to ? by B-cells

Answer 29

IgA

Question 30

what are some situations that seem to increase the likelihood of developing Tregs and overall tolerance?

Answer 30

○ Exposure to constant antigen levels for long periods of time
○ Exposure to antigen early in life
○ Exposure to antigen in tissue that “looks” healthy

Question 31

what are the key genes implicated in decreased tolerance and autoimmunity

Answer 31

IL-2R-alpha
CTLA4

Question 32

In the bone marrow, B-cells that encounter self-antigen have their ?

Answer 32

receptor shuffled

Question 33

In the spleen, B-cells that encounter self-antigen they ?

Answer 33

undergo apoptosis

Question 34

what are B cells that have survived negative selection in the spleen

Answer 34

T2 B-cells

Question 35

What provides the driving force for lymph to enter lymph capillaries?

Answer 35

Interstitial fluid build-up on the outside of the capillaries puts pressure on the capillary cells and forces them apart

Question 36

What provides the driving force for lymph to circulate in the larger lymphatic vessels?

Answer 36

• Contraction of skeletal muscle surrounding the lymphatic vessels
• Pressure created through breathing

Question 37

After exiting lymph nodes, lymph vessels combine to form

Answer 37

trunks

Question 38

Trunks combine to form one of two lymphatic ducts that drain into the blood system:

Answer 38

right lymphatic duct and thoracic duct

Question 39

The right lymphatic duct drains ?

Answer 39

the right arm, thoracic region, and right head/neck

Question 40

the right lymphatic duct drains into the

Answer 40

juncture of the right subclavian vein and right internal jugular

Question 41

the thoracic duct drains?

Answer 41

• Drains the rest of the body

Question 42

the thoracic duct drains into ?

Answer 42

the juncture of the left subclavian vein and left internal jugular