Brainscape's Knowledge GenomeTM

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


See full index

Immunology > lecture 1: Innate And Adaptive Immunity > Flashcards

lecture 1: Innate And Adaptive Immunity Flashcards

0
Q

Cells with adapted immunity increase ________ and _______ of response to antigen second exposure.

A

Rate and size

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

4 concepts of adaptive immunity

A
  1. Inducible
  2. Specificity
  3. Memory
  4. Self-tolerance (non-responsive to self)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What cells secrete antibodies?

A

B cell lymphocytes

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

Under what morphological conditions to antigens activate B cells?

A

When they have more than 1 identical epitope because the B cells are only activated when their antigen specific receptors are cross-linked by more than one epitope

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

True or false: antibody-antigen interactions are permanent

A

-False: they are reversible and follow the law of mass action

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

2 ways to increase the binding/effectiveness of an antibody for an antigen are…

A
  1. increase the affinity

2. Increase the valency of antibody

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

Does valency of an antibody have pertain more to avidity or affinity?

A
  • Avidity: which is the sum total of antigen binding at all Ag binding sites
  • Whereas affinity measures the strength of binding at single binding site
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What flanks CDRs in the variable region of an antibody?

A

Framework regions: regions important for Ig fold structure that are less variable in sequence

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

Framework regions contain hypervariable regions called ______. How many are there and what do they do?

A

CDR: complementarity determining regions

  • 3 of them
  • make the contact with antigen
  • loops
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do antibodies achieve their specificity?

A

-Occurs through unique combinations of heavy and light chain variable regions

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

What determines what isotype an antibody is?

A

-Heavy chain constant region

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

Which molecules (large or small) are eluted first in column chromatography?

A

-Larger molecules

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

Experiments have shown that antibody size changes with time of response. What is this relationship and why does this occur?

A
  • Larger antibodies on day 7 and then smaller antibodies on day 21
  • First Ab made is IgM and then switches to IgG
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

In what morphological state can IgA cross the epithelial barrier?

A

-As dimers (polymers)

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

Antibodies Fc region is important in initiating effector activities. What are the 4 chief effector activities?

A
  1. Opsonization
  2. Antibody-dependent cell-mediated cytotoxicity
  3. Complement
  4. Neutralization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Opsonization mechanism

A
  1. IgG subclasses bind to microbes
  2. Then recognized by FcR on phagocytes
  3. Signals from FcR promote phagocytosis of opsonized microbes and activate phagocytes to destroy microbe
16
Q

Ab-dependent cell-mediated cytotoxicity mechanism

A
  • Ab of certain IgG subclasses bind to cells
  • Fc regions of bound Ab recognized by Fc(gamma)R on Natural Killer cells
  • NK cells activated to kill antibody-coated cell
17
Q

Mast cell degranulation

A
  • Mast cells express FcER that binds IgE molecules
  • Activated when allergen cross links the IgR bound to FcER
  • Rapid release of chemical mediators
18
Q

Chemical mediators released from mast cells upon allergen interactions cause what 3 responses?

A
  1. Increase vascular permeability
  2. Vasodilation
  3. Bronchial and visceral smooth muscle contractin
19
Q

Classical pathway of complement activation:

A
  • cascade of serum proteins which can be activated by Ab-Ag complexes
  • Complement disposition marks them for destruction
  • Accomplished by enzymatic activity that results in nonselective ion channels being drilled in cell surface
  • Initiated by IgM or >2IgG
20
Q

3 mechanisms of neutralization by antibodies

A
  1. prevent binding of microbes to cells and thus blocks the ability of microbes to infect host cell
  2. inhibit spread of microbes from an infected cell to an adjacent uninfected cells (viral infections)
  3. block binding of toxins to cells and thus inhibit the pathological effects of the toxins
21
Q

Pepsin vs. Papain digestion of antibodies

A

Pepsin: end with 2 pieces; 1 bivalent Fab2’ and 1 Fc fragment

Papain: end with 3 pieces; 2 monovalent Ag-binding lacking avidity and 1 Fc’ fragment

23
Q

IgM

A 
primary response
low affinity
high avidity
best at fixing complement
-naive B cell antigen receptor and complement activation
24
Q

IgG

A

secondary response
high affinity
crosses placenta circulation
-opsonization, complement activation, ADCC, neonatal immunity, feedback inhibition of B cells

25
Q

IgA

A

mucosal immunity
dimer crosses epithelia
-neutralization

26
Q

IgE

A

Defense against parasites
elevated in allergic reactions
mast cell degranulation
-defense against helminthis parasites, immediate hypersensitivity

27
Q

IgD

A

co-expressed with IgM on naive B cell surface

unknown function

28
Q

Plasma vs. Serum definitions.

A
  • plasma is the soluble fraction of blood including clotting factors
  • serum is the soluble fraction of blood without the clotting factors
29
Q

What is an antibody and what is another name for it?

A
  • soluble (mainly serum) proteins secreted by cells of the B cell lineage that bind to offending agents such as pathogens or toxins
  • aka immunoglobulins (bc they are globular proteins
30
Q

Antigen and antigenic-determinant definitions.

A
  • Antigen: any foreign substance that induced a specific immune response
  • antigenic determinant: the site(s) on an antigen that are physically bound by antibodies (aka epitope)
31
Q

What do we call molecules with only 1 epitope?

A

-haptens

32
Q

Begin with a cloudy test tube that is full of pre-existing Ab-Ag complexes. What would happen if you added excess antigenic determinants (haptens)? What does this tell us?

A
  • causes the precipitates to dissolve

- shows that antibody-antigen interactions are reversible and therefore, follow the law of mass action

33
Q

T/F: Both heavy and light chains have CDRs.

A
  • true

- antibodies physically contact antigens via the CDR regions of the heavy and light chains

34
Q

When referring the antibody isotypes, what is different?

A
  • the heavy chain constant regions

- these different contant regions that make up these heavy chain isotypes elicit different types of effector activities

35
Q

What is always the first antibody isotype produced in antibody responses?

A

-IgM

36
Q

What antibody isotype is responsible for opsonization?

A

-IgG subclasses

37
Q

What antibody isotype is responsible for antibody-dependent cell-mediated cytotoxicity? Why type of cell do they activate that carries out this function?

A
  • IgG subclasses

- Natural killer cells

38
Q

What 2 antibodies can trigger the classical pathway of complement activation?

A
  • IgM or IgG on cell membrane of bacterium

- leads to formation of MAC complex

Immunology (13 decks)

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