Brainscape's Knowledge GenomeTM

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


See full index

MIMM 314 > Lecture 14 (pt 1) > Flashcards

Lecture 14 (pt 1) Flashcards

1
Q

where do B cells originate?

A

in the bone marrow

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

3 stages of B cells in BM

A
  1. pro-B cell
  2. pre-B cell
  3. immature B cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what happens at each stage of B cells in BM?

A

at each stage BCR undergoes VDJ recombination

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

where do B cells go after BM?

A

Secondary lymphoid organs

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

describe dependence on antigen in BM vs secondary lymphoid organs

A

antigen independent in BM

antigen dependent in secondary lymphoid organs

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

3 subsets of B cells in periphery?

A
  1. follicular (B2) B cells
  2. marginal zone B cells
  3. B1 B cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

where are follicular B cells located?

A

in secondary lymphoid organs

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

where do follicular B cells originate?

A

BM

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

are follicular B cells T cell DEPENDENT or INDEPENDENT?

A

T cell dependent

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

what is the main function of marginal zone B cells?

A

generate Ab in the fastest way possible

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

are marginal zone B cells T cell DEPENDENT or INDEPENDENT? why?

A

T cell independent bc want to generate Ab as fast as possible

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

where are marginal zone B cells located?

A

secondary lymphoid organs

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

what proportion of B cells in the spleen are marginal zone B cells?

A

5% of B cells in spleen

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

describe role of B1 B cells relative to B2 and MZ B cells?

A

B1 B cells are between B2 and MZ B cells

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

where are B1 B cells located?

A

in pleural and peritoneal cavities and mucosa

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

why are B1 B cells unique?

A

they are self-renewing and arise from division of pre-existing B cells

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

role of B1 B cells

A

first-line response at mucosa to make neutralizing IgM

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

Describe type of antigen that activates T-dependent B cells

A

protein

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

How do T-dependent B cells make Ab?

A

requires activation by Th to make Ab

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what type of B cells are produced in T-dependent response?

A

B2 B cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

2 types of antigens in T-independent response

A

TYPE 1 antigen = LPS, bacterial DNA

TYPE 2 antigen = highly repetitive surface structures (like flagellin)

22
Q

How do T-independent B cells make Ab?

A

does not require activation by Th to make Ab

23
Q

what type of B cells are made in T-indepedent?

A

B1 and MZ B cells

24
Q

describe activation of B cells in T-independent response

A

antigen binds BCR which directly activates the B cell without T cell

25
Q

in the T-independent response, describe the activation of B cells when there is HIGH CONCENTRATION OF TYPE 1 antigen

A

at high concentrations, the antigen is mitogenic bc it binds PRRs on B cell surface

26
Q

in the T-independent response, describe the production of Ab when there is HIGH CONCENTRATION OF TYPE 1 antigen

A

produces polyclonal Ab with varying specificity

27
Q

in the T-independent response, describe the activation of B cells when there is LOW CONCENTRATION OF TYPE 1 antigen

A

at low concentrations, B cells will ONLY activate if Ag binds thru Ig receptor

28
Q

in the T-independent response, describe the production of Ab when there is LOW CONCENTRATION OF TYPE 1 antigen

A

only produces monoclonal Ab with 1 type of specificity

29
Q

why does low concentration of type 1 antigen produce monoclonal antibody in T-independent response?

A

at low [Ag], B cells can only activate if they bind Ig receptor so the B cell only recognizes those with highest affinity so only makes B cell with 1 type of specificity

30
Q

what determines whether T-independent is polyclonal or specific?

A

[Type 1 antigen)

31
Q

example of type 2 antigen

A

capsular polysaccharide antigen

32
Q

since the type 2 antigen is repeated on the pathogen surface, what does this lead to?

A

multiple BCR bind the antigen –> crosslinking which leads to B cell activation

33
Q

what type of B cells does T-independent response to type 2 Ag activate?

A

MATURE B cells

34
Q

who does not have the T-independent response?

A

children <5

35
Q

why do children <5 not have the T-independent response?

A

T-independent response requires mature B cells and children <5 don’t have mature B cells

36
Q

what Ab does the T-independent response make in response to Type 2 antigen?

A

IgM with LOW affinity

37
Q

why does the T-independent response make low affinity IgM with Type 2 antigen?

A

There are no modifications (isotype switch, SHM, memory) that increase affinity

38
Q

is there memory in T-independent response to Type 2 antigen?

A

no

39
Q

why is there no memory in T-independent response to Type 2 antigen?

A

B cells don’t go thru germinal center (don’t need to be activated by T cells)

40
Q

role of T-independent response to type 2 antigen

A

to quickly clear pathogen

41
Q

2 signals in T-dependent response

A
  1. Ag binds and crosslinks Ig receptor
  2. Ag is processed and presented on MHC to be recognized by TCR on Th
42
Q

what happens in the 2nd signal in addition to the p:MHC and TCR interaction?

A

CD40L on T cell interacts with CD40 on B cell

43
Q

what does the 2nd signal in T-dependent response lead to?

A

allows T cell to secrete cytokines (IL-21) that can activate B cell

44
Q

what happens if B cell does not receive signal from T cell?

A

B cell will be deleted or anergized

45
Q

5 things that help from the Th cell leads to

A
  1. B cell expansion
  2. SHM
  3. Affinity maturation
  4. Isotype switching
  5. memory
46
Q

what is required to make memory B cells?

A

Th cells!

47
Q

how do the PREVNAR and Hib vaccines work?

A

both have repetitive polysaccharide structure on their surface to generate T-independent response

48
Q

what is the issue with PREVNAR and Hib vaccines?

A

they don’t work in kids because they cannot induce T-independent response

49
Q

how can you allow PREVNAR and Hib vaccines to work in kids?

A

use hapten-carrier where polysaccharide can be conjugated to a protein that will be recognized by a B cell –> both polysaccharide and protein will be presented to the T cell and allow production of Ab against polysaccharide

50
Q
A

MIMM 314 (23 decks)

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