Brainscape's Knowledge GenomeTM

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


See full index

Immunology > Dendritic Cells & Antigen Processing (9) > Flashcards

Dendritic Cells & Antigen Processing (9) Flashcards

1
Q

What do antigen-processing cells do?

A

recognize foreign materials
process large proteins by breaking them into peptides and presenting on their surfaces MHC

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

What are the 3 major APCs

A

dendritic cells
macrophages
B-cells

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

What do antigen-processing cells present on their surfaces?

A

specialized antigen-presenting structures

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

What is the Major Histocompatibility Complex (MHC)?

A

specialized antigen-presenting structures

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

What are naive T-cells?

A

those that have not been presented with their antigen before

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

What is the only APC that can present to naive T-cells and trigger a primary immune response?

A

dendritic cells

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

Define Bcells in the context of being an APC

A

presents the antigen to memory TH cells

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

Define macrophages in the context of being an APC

A

present antigen to memory TH cells

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

Where are dendritic cells found?

A

present primarily in epithelial tissues (skin, mucosa)
lymphoid organs (lymph node, spleen, thymus)

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

Give an example of an antigen-sensitive cell?

A

T-cells

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

What are major functions of dendritic cells?

A

serve as sentinel cells - activate innate defenses
process exogenous antigens - initial adaptive immune system
regulate adaptive immunity

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

Dcs are _____x more efficient APCs

A

100

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

What can dendritic cells take up?

A

dead microorganisms
soluble antigens
antigen released by dead cells

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

T/F: Only DCs can activate memory T cells

A

FALSE - naive!

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

How are follicular dendritic cells different than normal dendritic cells? (FDCs)

A

do not migrate
are located in lymphoid follicles (B cell area)
lack MHC II molecules on their surface
carry many complement and Fc receptors

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

T/F: FDCs do not process antigens

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Follicular dendritic cells can retain the antigen for _____

A

many weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the primary function of follicular dendritic cells?

A

present antigen to Bcells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The tentacles of FDC are called _______

A

beaded dendrites

20
Q

What is the significance of beaded dendrites on FDCs?

A

antigen:antibody complexes that have attached to the dendrites via complement and Fc receptors

21
Q

What are iccosomes?

A

spherical bodies formed by immune complexes

22
Q

What do immature dendritic cells do? It has [high/low] adhesion

A

antigen uptake/processing
low adhesion (not ready to present antigen)

23
Q

What do mature dendritic cells do? It has [high/low] adhesion

A

antigen presentation
high adhesion (ready to present antigen to helper T cells)

24
Q

What are lagerhan cells?

A

dendritic cells present in skin

25
Q

Plasmacytoid dendritic cells are the biggest producers of ______ and has [high/low] _____ activity as a result

A

IF-alpha, beta, gamma
high
antiviral

26
Q

Iccosomes break off from dendrites and subsequently attach to ______

A

Bcells

27
Q

Activated Bcells ingest ______ with B-cell receptors specific for the antigens. What happens next?

A

iccosomes
Antigen is processed
Bcell presents the antigen on MHC II molecules to activated T-helper cells (secondary immune response)

28
Q

What is macropinocytosis?

A

dendritic cells take in extracellular fluid to sample for signs of pathogens and their products

29
Q

DCs pick up _____ from site of infection and take them to an environment that is full of ______

A

antigens
immune cells

30
Q

Activated dendritic cells stop ______, move to the nearest interstitial space, and are carried by lymph flow to the nearest ________

A

phagocytosis
lymph node

31
Q

What stimulates activated dendritic cells to move to the lymph node?

A

the inflammatory cytokine TNF-alpha

32
Q

During the journey, activated DCs upregulate the expression of ______ molecules and co-stimulatory molecule _____

A

MHC II
B7

33
Q

When the activated DCs arrive in the lymph node, TH cells scan the large array of ______ for their cognate antigen

A

peptides

34
Q

How many signals do DC cells have to stimulate helper T cells?

A

3

35
Q

What is the first signal important during antigen presentation?

A

T-cell antigen receptors bind antigen fragments attached to MHC molecules

36
Q

What is the second signal important during antigen presentation?

A

co-stimulatory molecules like CD40 and CD80/86

37
Q

What is the third signal important during antigen presentation?

A

provided by cytokine secreted by DCs in response to microbial stimulus

38
Q

T/F: Macrophages are NOT efficient antigen presenters

A

TRUE

39
Q

Why aren’t macrophages good APCs?

A

when resting, they do not express adequate levels of MHC II and/or co-stimulatory molecules

40
Q

When are macrophages good APCs?

A

when they are activated by cytokines such as INF-gamma
expression of MHC II and co-stimulatory molecules are up-regulated
now can function as APC

41
Q

When are Bcells NOT good APCs?

A

when they are naive because they do not express the co-stimulatory B7 molecule needed for T-cell activation and also express low levels of MHC II molecules

42
Q

When are Bcells good APCs?

A

once they are activated by T-helper cells
now are efficient APCs

43
Q

Activated Bcells up regulate the expression of ______ and of co-stimulatory ______ molecules. They become a very potent activator of _______

A

MHC II
B7 molecules
T-helper cells

44
Q

Bcells play a more significant role in [primary/secondary] immune response

A

secondary (need to become activated)

45
Q
A

Immunology (36 decks)

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