Lecture 21 - T Cell Trafficking

Question 1

Definition of naive T cells

Answer 1

Fully-developed T cells found in lymphoid organs that have not been activated by cognate interaction

Question 2

Time for a naive T cell to make a full circuit

Answer 2

~24 hours

Question 3

Naive T cell circulation circuit
1)
2)
3)
4)
5)

Answer 3

1) Lymph node
2) Enters efferent lymphatics
3) Efferent lymphatics empty into thoracic duct
4) Thoracic duct returns lymph to blood
5) Enter lymph nodes through HEV

Question 4

Where can naive T cells never be?

Answer 4

Afferent lymphatics leading to tissue, tissue

Question 5

Area of an artery with the least shearing force

Answer 5

Marginal pool (edges of artery)

Question 6

What is tissue-specific migration of T cells called?

Answer 6

Homing

Question 7

Do selectins or integrins bind with higher affinity?

Answer 7

Integrins

Question 8

T cell surface molecule used for rolling

Answer 8

L-selectin

Question 9

T cell surface molecule used for adhesion to endothelial wall

Answer 9

LFA-1

Question 10

Another name for L-selectin

Answer 10

CD62-L

Question 11

What is CD62-L?

Answer 11

L-selectin

Question 12

What does L-selectin bind to?

Answer 12

Addressins

Question 13

Addressin to HEV

Answer 13

GlyCAM-1

Question 14

Addressin to endothelial cells

Answer 14

CD34

Question 15

Addressin to endothelial cells in gut-associated lymphoid tissues

Answer 15

MadCAM-1

Question 16

Where is GlyCAM-1 used as an addressin?

Answer 16

HEV

Question 17

Where is CD34 used as an addressin?

Answer 17

Endothelial cells

Question 18

Where is MadCAM-1 used as an addressin?

Answer 18

Endothelial cells in gut-associated lymphoid tissue

Question 19

Chemokines associated with T cell diapedesis

Answer 19

CCL21, CXL12

Question 20

Integrins
1)
2)
3)

Answer 20

1) Bind tightly to ligands
2) Signal through conformational changes
3) Large family of molecules, alpha and beta subunits

Question 21

What does LFA-1 bind to?

Answer 21

ICAM-1

Question 22

ICAM-1 minding molecule

Answer 22

LFA-1

Question 23

What stimulates a naive T cell to become more adhesive to endothelial walls?

Answer 23

T cell hitting arterial wall causes conformational change in adhesion molecules

Question 24

What do naive T cells always express at a high level?

Answer 24

CCR7

Question 25

Where in a lymph node do HEV lie?

Answer 25

Paracortex

Question 26

How do naive T cells enter lymph nodes?
1)
2)
3)

Answer 26

1) Through HEV, into paracortex
2) Attracted to DCs with CCL19, CCL21 with CCR7
3) Probe DCs for antigen

Question 27

Name of cluster of adhesion and costimulatory molecules between a T cell and a DC

Answer 27

Immunological synapse

Question 28

What is an immunological synapse?

Answer 28

Collection of integrins, MHC/TCR, CD28/CD80/86 and other molecules between T cell and DC

Question 29

How long do cognate T cells and DCs bind together for?

Answer 29

Hours

Question 30

Distribution of microclusters in naive T cell

Answer 30

Evenly distributed

Question 31

What happens to mice without LFA-1?

Answer 31

No T cell activation
Immunological synapse is improperly formed, even if cognate with DC
LFA-1 can’t cause tight binding of DC and T cell

Question 32

State of IL-2 receptor in naive T cell

Answer 32

Only beta and gamma subunits present

Weakly respond to IL-2

Question 33

State of IL-2 receptor in activated T cell

Answer 33

Alpha, beta and gamma subunits present

Strongly respond to IL-2

Question 34

T cell function that requires IL-2

Answer 34

Entry into the cell cycle (division)

Question 35

T cell retention signal in lymph node

Answer 35

CD69

Question 36

T cell exit signal from lymph node

Answer 36

S1P1

Question 37

How does S1P1 stimulate T-cells leaving lymph node?

Answer 37

S1P1 very strongly present in efferent lymph

When a T cell is activated, it begins expressing a lot of S1P1 receptor

Question 38

Phenotype of T cells being retained in a lymph node

Answer 38

Highly express CD69 receptor, weakly express S1P1 receptor

Question 39

Can a T cell strongly express both CD69 and S1P1?

Answer 39

No