Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

3 IIH > 8.1 T cell activation, expansion, and variation > Flashcards

8.1 T cell activation, expansion, and variation Flashcards

1
Q

What does a naive cell do?

A

it circulates between the lymph and blood searching for an antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When is MHC expressed in dendritic cells?

A

it is low on immature cells and high on cells in lymphoid tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When is MHC expressed on Macrophage?

A

inducible by bacteria and cytokines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

When is MHC expressed on B cells?

A

always have a high level of MHC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where are langerhans resident?

A

epidermis of the skin, only when challenged do they enter lymph drainage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is significant about the chemokines peesent on immature dendritic cells?

A

CCR1,2,5,6
inflammatory chemokines
it will down-regulate these and switch on CCR7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does CCR7 do?

A

directs migration into lymphoid tissues and augments expression of co-stimulatory molecules and MHC molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what happens if naive T cells contact a dendritic cell with the right peptide-MHC complex?

A

activates the T cell

the T cell will then exit the lymph node to populate the periphery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 3 sorts of signals received by T cells?

A

1 - activation
2 - survival
3 - differentiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what happens in the activation signal?

A

TCR binds to peptide : MHC complex

For a naive T cell, signal 1 is not enough and often causes the cell to switch off

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What happens in the survival signal?

A

B7’s bind to CD28 on the T cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is CD28?

A

a costimulatory molecule, producing a strong cell stimulatory molecule helping survival

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens in the 3rd stage of T cell singalling?

A

The activated T cell expresses IL-2 receptor alpha, which is higher affinity for IL-2

it can then produce the proteins required to proliferate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens to T cells as they differentiate?

A

form CD8, CD4

also retain some cells as memory T cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why do our lymph nodes swell up?

A

during infection, we massively increase proliferation of T and B cells

this isn’t want we want all the time though

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are CD8 cells designed to do?

A

cytotoxic T cells
control viral infections
protein on MHC class I is derived intracelllularly

17
Q

What are the 2 major killing mechanisms of CD8+ cytotoxic T cells?

A

granules containing perforin and granzymes

Fas ligand (FasL) on T cell binds to Fas on the target cell triggering apoptosis

18
Q

What does perforin do?

A

plugs a hole in an infected cell membrane

19
Q

What does granzyme do?

A

activates apoptosis

20
Q

What re the 5 main types of CD4+ cells?

A 
CD4 TH1
CD4 TH2
CD4 TH17
CD4 TFH
CD4 Treg
21
Q

What cytokine stimulates differentiation into a CD4 TH1 cell?

A

IL-12

22
Q

What do CD4 TH1 cells secrete?

What does it do?

A

IFN - gamma

enhances differentiation into TH1

23
Q

What is the rough function of TH1?

A

controls intracellular infection

particularly vacuole restricted bacteria (via IFN - gamma receptor on macrophage)

24
Q

How do TH1 cells control M. tuberculosis?

A

sheath of Th1 cells forms around the collection of fused macrophage, forming a granuloma

25
Q

What cytokine stimulates differentiation into the TH2 prototype?

A

IL-4

26
Q

What do TH2 cells do?

A

produce IL-4, important in large extracellular helminth parasite defence

TH2 promotes B cell class switching towards IgE

27
Q

What cytokine stimulates differentiation into the TH17 prototype?

A

IL-6

28
Q

what do TH17 cells secrete?

What is the significance of this?

A

IL-17
NOT IFN - gamma

(this is an easy way to differenciate TH17 and TH1)

29
Q

What is the rough function of TH17 cells?

A

important to control fungal and bacterial infections

30
Q

Where are TFH cells found?

A

near folllicles in the lymph node, they help B cells

31
Q

What do TFH cells do?

A

switch off CCR7 which keeps them int he T cell zone

they then switch on CXCR5, allowing them to get into the B cell zone

they then help the B cells

32
Q

What cytokine drives TFH?

A

IL-21

the key thing here is to upregulate CXCR5

33
Q

What is the rough function of Treg cells?

A

control the immune response, to prevent it from becoming pathological

34
Q

What types of Treg cells are there?

A

thymic

peripheral

35
Q

What drives the differentiation of Treg?

A

TGF beta
retinoic acid

have their own transcription factor called FoxP3

3 IIH (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions