Brainscape's Knowledge GenomeTM

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


See full index

Micro > B cell maturation > Flashcards

B cell maturation Flashcards

1
Q

what kind of receptor do B cells express

A

B cell receptor (BCR)

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

how does BCR recognize antigen

A

via membrane Ig

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

T/F the BCR on each B cell clone is specific for a distinct antigen

A

True

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

what are the five Ig types

A

IgG, IgE, IgM, IgA, IgD

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

Ig isotype is based on what

A

heavy chain

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

which Ig(‘s) is/are monomeric with 2 binding sites

A

IgD, IgE, IgG

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

which Ig(‘s) is/are pentamers with 10 binding sites

A

IgM

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

which Ig(‘s) is/are dimers with 4 binding sites

A

IgA

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

Ig are Y shaped molecules formed by:

A

two heavy chains and two light chains

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

what does the light chain consist of

A

1 variable domain and 1 constant domain

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

what does the heavy chain consist of

A

1 variable domain and 3 or 4 constant domains

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

what are the two forms that Ig can exist in

A

membrane-bound or secreted

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

which region contains the antigen binding site

A

variable regions

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

which region mediates the effector function? and what are those funcitons?

A

constant region.
- determines isotype
- bind complement
- bind Fc receptors

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

how many bind sites are there per Y structue

A

2

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

does variable chain bind wide variety of antigen or a very specific type of antigen

A

wide variety (in contrast with T cells):
- proteins
- lipids
- polysaccharides
- nucleic acid

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

does variable chain recognize processed or non-processed antigen

A

native not processed antigen is recognized
(in contrast with T cell receptor which recognizes processed peptide)

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

what is the antigen part recognized by antibody

A

epitope

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

which is the first C region cluster

A

Cu (greek letter mu)

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

which is the first antibody to be produced

A

IgM

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

during recombination of Ig genes, is it randomly selected or precisely selected?

A

random

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is the random recombination mediated by

A

RAG specific for VDJ
- brings two segments close together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how else is diversity generated for Ig

A

exonucleases and Tdt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

where does B cell positive selection occur

A

bone marrow

25
Q

is positive selection for B cells antigen dependent or independent

A

antigen independent

26
Q

what are the two checkpoints in B cell maturation

A

preBCR and IgM

27
Q

T/F B cell needs either preBCR or IgM to promote survival

A

False. It needs both preBCR and IgM

28
Q

what is negative selection for B cells

A

eliminate B cells that can bind with high affinity ubiquitous self antigens

29
Q

what else can a B cell do instead of dying that results in change of the Ig specificity

A

Receptor editing

30
Q

what do plasma cells produce

A

high affinity Ig

31
Q

where do plasma cells migrate to and how long do they survive

A

Bone marrow or mucosal tissues
survive for years

32
Q

do memory B cells secrete Ig

A

nope

33
Q

how long do memory B cells survive and where

A

a lifetime in mucosal tissues and blood

34
Q

compare secondary antibody response to primary antibody response in terms of
1. response time
2. response amount
3. antibody type
4. antibody affinity

A

Primary: slower, smaller, IgM > IgG, low affinity
Secondary: quicker, larger, IgG more abundant, high affinity

35
Q

what are two to enhance B cell activation

A
  1. simultaneous engagement of antigen receptor (BCR) and CR2
  2. TLR
36
Q

what delivers the CR2 activating signal

A

CD19 and CD81

37
Q

what are the two types of antibody responses

A

T dependent response and T independent response

38
Q

for the T dependent response, what kind of antigen, what Ig, and what kind of affinity?

A
  • protein antigen (T cells only recognize protein antigens)
  • isotype switching
  • high affinity Ig
39
Q

for the T independent response, what kind of antigen, what Ig, and what kind of affinity?

A
  • nonprotein antigen
  • IgM
  • low affinity Ig
40
Q

define a hapten

A

small molecule that cannot elicit an immune response by themselves but do so after bind to larger proteins or cells

41
Q

what are the steps of T-B cell interaction and antibody responses?

A
  1. simultaneous activation of T and B cells by antigen in T cell zone and follicle, respectively
  2. migration towards each other
  3. B cells migrate back to follicles where germinal center rnx occurs
42
Q

which chemokine is for T cells to go to T cell zone

A

CCR7

43
Q

which chemokine is for B cells to go to B cell zone (follicle)

A

CXCR5

44
Q

during antigen presentation by B cells to T helper cells, which cell processes the antigen

A

B cells

45
Q

T/F B cells and T cells recognize different epitopes of the same protein

A

True

46
Q

which protein epitope do B cells recognize

A

native conformational epitope

47
Q

which protein epitope do T cells recognize

A

peptide fragments

48
Q

when T cell recognizes peptide presented to it by the B cell, what does this induce

A

CD40L upregulation in T cells and production of cytokines

49
Q

in the B and T cell interaction, where is CD40 present and where is CD40L present?

A

CD40 on B cells
CD40L on T cells

50
Q

what does engagement of CD40 and cytokine receptor on B cells lead to

A

proliferation and differentiation in plasma cells

51
Q

what 3 things happen in the germinal center

A

isotype switching
affinity maturation
selection of high-affinity B cells

52
Q

what is isotype switching

A

change in the C region of the heavy chain with no change in specificity (recognition of antigen doesn’t change)

53
Q

what does isotype switching require

A

CD40L signal from Tfh (T follicular helper cells)

54
Q

the type of heavy chain isotype is determined by what

A

cytokines produced by Tfh cells (IgG and IgE) or tissues (IgA)

55
Q

what happens during switch recombination

A

the VDJ exon is brought next to a different C gene

56
Q

T/F during switch recombination the specificity of the Ig does not change, while the C region is different and reflected the function of the Ig

A

True

57
Q

what is affinity maturation

A

point mutation in the V regions
- selection of B cells with high-affinity antigen receptors

58
Q

during selection of high-affinity B cells, what interactions promote their survival

A

interactions with follicular DC that display antigen and Tfh cells

59
Q

T/F B cells compete for antigen and those with low affinity for antigen will survive

A

False. those with high affinity will survive

Micro (15 decks)

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