Lecture 11

Question 1

Where are adaptive immune responses initiated?

Answer 1

secondary lymph organs

Question 2

Which cell first recognizes Ag in an infected tissue?

Answer 2

dendritic cells

Question 3

name the three APCs

Answer 3

DC, macrophages, B cells

Question 4

What do dendritic cells do that the other APCs do not?

Answer 4

drive initial clonal expansion by activating NAIVE T cells

Question 5

Macrophages present Ag from what type of pathogen?

Answer 5

extracellular

Question 6

What do macrophages interact with?

Answer 6

primed effector CD4 cells

Question 7

What do B cells process and present?

Answer 7

soluble Ag

Question 8

What do B cells interact with?

Answer 8

primed effector CD4 cells

Question 9

What is different about B cell Ag uptake in comparison to DC and Mac?

Answer 9

B cells have Ag-specific receptors as opposed to recognition via macropinocytosis or phagocytosis

Question 10

What happens to dendritic cells in terms of size as they go from infected tissue to lymphoid tissue?

Answer 10

they decrease in surface area

Question 11

What are the pathways that DCs can process and present bacterial Ag?

Answer 11

receptor-mediated endocytosis, macropinocytosis

Question 12

What are the pathways that DCs can process and present viral Ag/infection?

Answer 12

macropinocytosis, MHC class I binding to a CD8 T cell, cross-presentation on an MHC I molecule

Question 13

What two routes can naive T cells enter a draining lymph node?

Answer 13

1. in the blood
2. in the afferent lymph coming from an upstream lymph node

Question 14

In the draining lymph node, what causes clonal expansion of naive T cells?
NOTE: clonal expansion means they are now activated

Answer 14

Binding of the DC presenting Ag to the TCR

Question 15

What happens when L-selectin binds to GlyCAM-1?

Answer 15

causes the rolling mechanism

Question 16

What happens when the T cell binds a chemokine?

Answer 16

increases the binding affinity of LFA-1

Question 17

What happens when LFA-1 binds ICAM-1?

Answer 17

diapedesis - lymphocyte leaves blood and enter lymph node

Question 18

In priming naive T cells, what mediates the initial interaction of the cell with an APC?

Answer 18

cell-adhesion molecules

Question 19

What is the immunological synapse?

Answer 19

the area of contact between a naive T cell and a DC

Question 20

The C-SMAC is made up of ___, ___, and __-___________ _________

Answer 20

TCR, CD3, and co-stimulatory molecules

Question 21

The P-SMAC is made up of what?

Answer 21

adhesion molecules

Question 22

What are ITAMs? What is their function?

Answer 22

Immunoreceptor Tyrosine-based Activation Motifs function in signaling

Question 23

In TCR engagement, what do CD4/8 coreceptors bring in?

Answer 23

Lck

Question 24

What does Lck do?

Answer 24

phosphorylates ITAMs of CD3

Question 25

Name the five intracellular signals generated in TCR engagement.

Answer 25

1. phospholipase Cgamma 2. Ca2+ 3. protein kinase C 4. NF-kappaB 5. Ras/MAP pathway

Question 26

In co-stimulation, what are the two signals?

Answer 26

1. TCR 2. CD28

Question 27

What does that co-stimulation eventually create?

Answer 27

Promoter region for IL-2

Question 28

What component of an activated T cell give it a high affinity?

Answer 28

bound IL-2

Question 29

What cytokine drives T cells proliferation and differentiation?

Answer 29

IL-2

Question 30

What happen to a T cell that binds only the Ag instead of both the Ag and the co-stimulator?

Answer 30

It becomes anergic (nonresponsive)

Question 31

What are the three signals APCs deliver?

Answer 31

1. TCR binding MHC peptide 2. CD28 binding B7 3. cytokines binding TCRs

Question 32

The TCR-binding MHC is necessary for __________

Answer 32

activation

Question 33

CD28 binding B& is necessary for ________

Answer 33

survival

Question 34

cytokine release and binding is necessary for _______________

Answer 34

differentiation

Question 35

What is the function of Treg cells?

Answer 35

to suppress other effector T cells