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Flashcards in L12 Deck (27)
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1

How many signals do naive T cells need for activation? Effector T cells? What happens in each step?

Naive = 2 signals
- MHC & costim
- MAKE granules
Effector = 1, MHC
- Granule exocytosis

2

What changes occur to a draining lymph node?

↑inflammation
↑cytokines
Recruit lymphocytes - REGARDLESS of antigen specificity
Via selectins and integrins upregulated on HEVs

3

What are 3 important T cell receptors for lymph node honing? Explain their significance in context the steps towards diapedesis.

CD26L (selectin receptor)
- Binds L selectin on HEV
*Rolling/tethering*
CCR7 (chemokine receptor)
- Binds CCL12/21 on HEV
*Stimulation/signal*
LFA1 (integrin receptor)
- Binds ICAM on HEV
*Adhesion*

4

What is the significance of chemokine activation of vascular walls?

Inside out signaling
Integrin receptor changes from low --> high affinity
Get FIRM adhesion

5

What changes are made to recruit cells to specific tissues?

Modify chemokine receptor for tissue specific chemokines

6

What cytokine do CD8 T cells secrete? What is the fxn of this cytokine?

IFN gamma
Improves macrophage phagocytosis & inflammation

7

How do CD8 create MEMORY?

ADD CD4 to normal CD8 activation by DC
1. CD4 & CD8 recognize antigen on same DC
2. DC licensing

8

What is DC licensing?

CD40L from CD4 T cells or inflam signals (like TLRs on DCs) modify a DC to make it provide optimal help for CD8s

9

What are the 2 ways CD8 cells can actually kill cells?

1. Perforins + granzymes
2. Fas/FasL --> (suicide mechanism) DNA breakdown via caspases
Or some combo of both

10

What is the disease resulting from perforin deficiency?

Hemophagocytic lymphohistiocytosis (HLH)
- Genetic or acquired
- CD8s get revved up but can't do anything about it --> secrete INF gamma and get inflam, stimulate macrophages
Symptoms:
- Splenomegaly, fever, etc
- High levels of inflam cytokines in blood

11

How could you treat HLH?

Immuno-suppressants
+Ab against INF gamma - block macrophage recruitment and toxicity

12

Are CD8 cells one and done killers?

No - can kill multiple targets
As long as have enough granules

13

What cytokines make Th1 cells?

IL12
IFN gamma

14

What is the function of Th1 cells?

Fight intracellular pathogens
Autoimmunity

15

What cytokines do Th1 cells secrete? What cells are helped by this?

IFN gamma
Macrophages

16

What cytokines make Th2 cells?

IL4

17

What is the function of Th2 cells?

Extracellular parasites
Allergy

18

What cytokines do Th2 cells make? What cells are helped?

IL4 & 13
Mast cells, eosinophils, basophils

19

What cytokines make Th17 cells?

TGFbeta
IL 6
IL23

20

What is the function of Th17 cells?

Extracellular bacteria
Fungi
Autoimmunity

21

What cytokines do Th17 cells make? What cells are helped?

IL 12
IL 22
Neutrophils indirectly

22

What cytokines make Tregs? What is the molecular mechanism?

IL1-
TGF beta
Via FoxP3/Stat5

23

What cytokines do Treg make?

TGF beta
IL10

24

What Abs do Th1s influence the creation of? Th2?

Th1 = IgG 1 & 3 (opsonize)
Th2 = IgE & neutralizing Abs

25

What is the name for macrophages activates by Th1 cells?

Delayed type 4 hypersensitivity (DTH)

26

What is Job's syndrome?

Lose STAT3 fxn
No Th17
= primary immnodeficiency
Hyper IgE - unclear why

27

Explain the mechanism for getting Shingles (herpes virus 3).

As you age, T cell memory effectiveness decreases
Can't keep the intracell virus in check --> comes back