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Flashcards in L12 Deck (27)
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1
Q

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

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

What changes occur to a draining lymph node?

A

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

3
Q

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

A
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
Q

What is the significance of chemokine activation of vascular walls?

A

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

5
Q

What changes are made to recruit cells to specific tissues?

A

Modify chemokine receptor for tissue specific chemokines

6
Q

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

A

IFN gamma

Improves macrophage phagocytosis & inflammation

7
Q

How do CD8 create MEMORY?

A

ADD CD4 to normal CD8 activation by DC

  1. CD4 & CD8 recognize antigen on same DC
  2. DC licensing
8
Q

What is DC licensing?

A

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

9
Q

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

A
  1. Perforins + granzymes
  2. Fas/FasL –> (suicide mechanism) DNA breakdown via caspases
    Or some combo of both
10
Q

What is the disease resulting from perforin deficiency?

A

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
Q

How could you treat HLH?

A

Immuno-suppressants

+Ab against INF gamma - block macrophage recruitment and toxicity

12
Q

Are CD8 cells one and done killers?

A

No - can kill multiple targets

As long as have enough granules

13
Q

What cytokines make Th1 cells?

A

IL12

IFN gamma

14
Q

What is the function of Th1 cells?

A

Fight intracellular pathogens

Autoimmunity

15
Q

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

A

IFN gamma

Macrophages

16
Q

What cytokines make Th2 cells?

A

IL4

17
Q

What is the function of Th2 cells?

A

Extracellular parasites

Allergy

18
Q

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

A

IL4 & 13

Mast cells, eosinophils, basophils

19
Q

What cytokines make Th17 cells?

A

TGFbeta
IL 6
IL23

20
Q

What is the function of Th17 cells?

A

Extracellular bacteria
Fungi
Autoimmunity

21
Q

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

A

IL 12
IL 22
Neutrophils indirectly

22
Q

What cytokines make Tregs? What is the molecular mechanism?

A

IL1-
TGF beta
Via FoxP3/Stat5

23
Q

What cytokines do Treg make?

A

TGF beta

IL10

24
Q

What Abs do Th1s influence the creation of? Th2?

A
Th1 = IgG 1 & 3 (opsonize)
Th2 = IgE & neutralizing Abs
25
Q

What is the name for macrophages activates by Th1 cells?

A

Delayed type 4 hypersensitivity (DTH)

26
Q

What is Job’s syndrome?

A

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

27
Q

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

A

As you age, T cell memory effectiveness decreases

Can’t keep the intracell virus in check –> comes back