Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Immunology > Exam 3: Humoral Immune II > Flashcards

Exam 3: Humoral Immune II Flashcards

(47 cards)

Start Studying
1
Q

what do naïve B cells express that function as antigen receptors

A

IgM

IgG

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

what happens every time there is an immune response from the same antigen

A

antibodies have a higher affinity for the antigen

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

Do secreted antibodies have the same specificity as that of the naïve B cell membrane receptors that recognize antigens?

A

Yes

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

how many plasma cells to B cells generate once activated?

how many antibodies can they produce a day?

A

Once activated B cells can generate up to 4000 plasma cells

Can produce up to 10^12 antibody molecules per day

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

what is heavy chain isotype (class) switching

A

Some B cells may begin to produce antibodies with different heavy chain isotypes (classes), which mediate different effector functions and are specialized to combat different types of microbes

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

What is affinity maturation

A

repeated exposure to an antigen results in the production of antibodies with increased affinity

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

High affinity antignes

A

fit properly with antigen-binding site

maximum number of interactions occur

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

B cell co-receptors

A

bind to fragments of complement proteins and deliver an additional signal to the B cell nucleus

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

CD19 and CD21 interaction

A

when CD21 binds to CD19 –> increased activation of CD19

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

B cell travel through lymph nodes

A

Naive B cells leave bone marrow via blood

May encounter antigens in blood, lymph, or lymph nodes

If they don’t bind to an antigen or fail to find the correct Th cell they leave via efferent lymphatic vessels and move on to next lymph node

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

What are HEVs

A

specialized venules inside lymph nodes and peyer’s patches that have receptors for cell-surface proteins on T and B cells

This interaction allows T and B cells to exit the blood and enter lymph nodes

Inside Th cells encounter antigen presenting dendritic cells

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

Antigen processing and presentation by B cells inside Lymph Node

A

Mammalian B cell BCRs bind to antigen. Then via receptor mediated endocytosis, internalize the antigen-antibody complex.

The newly formed endosomes fuse with the lysosomes that contain both proteolytic enzymes and MHC II molecules.

The antigenic peptides bind to the MHC molecules and the MHC-antigen complexes return to the surface for presentation to Th cells.

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

B cells proliferate in lymph nodes germinal centers

A

After activation in the medulla, a large population of B cells moves to lymphoid follicles, proliferate, and form germinal centers

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

what are dividing B cells called

what are resting B cells called

A

dividing B cells - centroblast

Resting B cells - centrocytes

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

what types of cells do germinal centers contain

A

Centroblasts

Centrocytes

Th cells

Follicular dendritic cells

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

what happens to B cells in germinal centers

A

B cells undergo isotype switching and somatic hypermutation

Then emigrate the lymph node and differentiate into plasma cells that migrate to bone marrow

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

how to plasma cells leave the lymph node

A

efferent lymphatic vessels

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

what do plasma cells do

what do memory cells do

A

Plasma cells - produce antibodies

Memory cells - APC in secondary immune response

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

Primary immune response

Study These Flashcards
A
  1. First injection
  2. Naive B cell
  3. Activated B cells
  4. Antibody secreting cells in peripheral lymphoid tissues - plasma cells
  5. IgM production
  6. Long lived plasma cells in bone marrow
  7. Memory B cell
20
Q

Secondary immune response

Study These Flashcards
A
  1. Second injection
  2. Memory B cells
  3. Antibody secreting cells –> plasma cells
  4. IgG production
  5. Long lived plasma cells in bone marrow
  6. Memory B cell
21
Q

differences between primary and secondary immune response

Study These Flashcards
A

Primary - IgM, lower antibody production, slower antibody production

Secondary - memory B cells, IgG, higher antibody production, faster antibody production

22
Q

Effector mechanisms of antibodies - bacterial toxins

Study These Flashcards
A
  1. Specific antibody
  2. Bacterial toxins
  3. Cells with receptor for toxins
  4. Neutralization
  5. Ingestion by macrophage
23
Q

Effector mechanisms of antibodies - bacterial in extracellular space

Study These Flashcards
A
  1. Specific antibody
  2. Bacteria in extracellular space
  3. Macrophage
  4. Opsonization
  5. Macrophage with Fc receptor
  6. Ingestion and lysis by macrophage
24
Q

Effector mechanisms of antibodies - Bacteria in plasma

Study These Flashcards
A
  1. Specific antibody (IgM or IgG)
  2. Bacteria in plasma
  3. Complement activation - classical pathway
  4. Complement fragmentation
  5. Ingestion and lysis
25
how is the ability of a receptor to bind to an antigen determined
the shape of its binding site Shape --> folding of peptide chain --> amino acid sequences
26
where is the information needed to make proteins, including antigen receptors, located
the gneome
27
how many antigen binding receptors on B and T cells can mammals express (produce)
up to 10^15 different antigen binding receptors on B and T cells
28
How many genes to antigen binding receptors use
fewer than 500 genes
29
How many genes code for the variable region How many genes code for the constant region
Several genes code for variable region One gene codes for constant region
30
what contributes to gene diversity
Gene recombination Somatic mutation Gene conversion
31
Number of constant genes in B cell receptors
5 ``` 1 gene codes for IgM 1 gene codes for IgG 1 gene codes for IgE 1 gene codes for IgA 1 gene codes for IgD ```
32
how are antigen receptor genes coded
Antigen receptor genes are coded for by 3 genes originating in 3 widely separated groups. The genes for a complete receptor chain are assembled by joining one gene selected from each group. Variable genes - hundreds Joining genes - tens Constant gene - one
33
How many distinct light chain loci
2 1 coding for kappa chains 1 coding for lambda chains these are located on different chromosomes
34
which antibody is produced first
IgM (mu gene)
35
which antibodies do all B cells have
IgM (mu gene) | IgD (delta gene)
36
Which antibody is mainly produced in secondary immune response
IgG (gamma gene)
37
gene recombination
deleting unwanted genes by looping out unwanted genes form a loop that is then cut off by a recombinase enzyme and the cut ends are joined together
38
gene recombination - construction of an immunoglobulin light chain
selected V and J genes are joined as intervening genes deleted VJ and C genes remain separated until RNA splicing occurs intervening RNA segments are deleted leaving V, J, and C genes together in the mRNA DNA rearrangement occurs during early B cell development so each individual B cell is committed to making a single form of light chain for its antigen receptor
39
gene recombination - heavy chain construction
2 DNA rearrangement events are required to link V, D, and J genes together first rearrangement event joins selected D and J genes second rearrangement event adds selected V gene finally unwanted J genes are excised and VDJ joined to C in the mRNA
40
Gene recombination - B cell development
during development, each B cell has 4 attempts to make a productive gene rearrangement coding for a functional immunoglobulin if it fails all 4 attempts - apoptosis 1st attempt - first IGK gene rearrangement 2nd attempt - second IGK gene rearrangement 3rd attempt - first IGL gene rearrangement 4th attempt - second IGL gene rearrangement
41
How are CDR1, CDR2, and CDR3 formed on immunoglobulin light chain
CDR1 and CDR 2 - formed by somatic mutation or gene conversion CDR3 - formed by recombination of V and J gene segments
42
how are CDR formed on TCR
CDR - formed by recombination of V, (D), and J gene segments no somatic mutation
43
what is the major difference between the variable regions of the TCR and immunoglobulins
formation of CDRs immunoglobulins have 3 CDRs CDR1 and CDR2 - somatic mutation CDR3 - gene conversion TCR - somatic mutation is stringently avoided to prevent self reactivity
44
why is somatic mutation avoided in variable region of TCR
to prevent self reactivity
45
selection of somatic mutants
spontaneous mutation during expression of a B cell clone results in development of cells with antigen receptors that differ in affinity for antigen cells that bind antigen strongly will be more intensely stimulated than cells that bind it weakly as a result of this selection pressure, the B cell population gradually increases its binding affinity during the course of an antibody response if a mutation creates a B cell with reduced antigen binding - apoptosis
46
gene conversion
in this process segments of upstream genes or pseudogenes are inserted into a single V region to generate sequence diversity
47
where does gene recombination happen in T cell receptor
gene recombination only in variable region

Immunology (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions