Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

IHL Exam 2 > Antigen/Antibody Reactions (Bowden) > Flashcards

Antigen/Antibody Reactions (Bowden) Flashcards

(61 cards)

Start Studying
1
Q

Antibody

A

circulating antibodies
-soluble glycoproteins that recognize and bind antigens

-also function as membrane bound surface Antigen receptors on B cells and play a key role in B cell differentiation

they are the effector molecules of humoral immunity

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

5 classes of Antibodies

A 
IgG
IgM
IgA
IgE
IgD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what makes up the class of an antibody?

A

The heavy chains

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

Variable regions

A

Fab (fragment antibody)

where antigen binding occurs

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

Constant regions

A

Fc (fragment constant regions)

biology activity (site of effector function)

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

CDR’s

A

Complementary-determining regions
aka Idiotope
aka hypervariable region

within variable regions of both H and L chains
(Show exceptional diversity)

Hypervariable regions that are involved in Ag binding by creating an interaction site that is complementary in shape, charge, hydrophobicity to the epitope it binds

6 CDR’s per antibody

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

Classes also known as …

A

isotype

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

Allotype

A

Allelic differences in the heavy chains

we all have IgG but we all have subtle differences in the IgG

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

Idiotype

A

Antigenic determinants on the V regions

we all may see an antigen, but we respond with slightly different V region determinants

see the antigen differently

called Idiotypic Network

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

Which Ig isotype is NOT bifunctional

A

IgD

usually only on surface of b cells

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

Antibody functions

A

Binds to antigen and then:
-promotes killing or removal of the immune complex

does this by:

  • binding of the antibody to receptors expressed on host tissues
  • binding of the antibody to the first component of the complement system to initiate the classical pathway
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Immune complex

A

Antibody bound to an antigen

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

IgM

A

Pentamer- expressed on B cells
first antibody produced in primary response to antigen

good for binding Ag’s with multiple repeating epitopes (viruses, RBC’s)
good at binding complement

ha J piece
-binds to secretory cells- provides mucosal immunity

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

How long does it take for primary response to come up?

A

Two weeks

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

Why is IgM the first Ab made

A

Because IgM is the first constant region in the gene when looking at the constant regions

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

sIg

A

Secreted antibody

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

mIg

A

membrane bound antibody

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

IgG

A

80 percent of serum

functions:

  • opsonization
  • complement activation
  • antibody dependent cell-mediated cytotoxicity
  • neonatal immunity
  • feedback inhibition of B cells

peaks at birth

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

4 Subtypes of IgG

A

IgG1
IgG2
IgG3
IgG4

All can cross the placenta

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

IgG1 and IgG3

A

Bind with high affinity to Fc receptors on phagocytic cells (antibody binds with its C region)

this is opsonization, which leads to increased phagocytosis

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

IgG2

A

restricted to carbohydrate Ag’s

binds with low affinity

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

IgG3

A

efficient activator of C’ b/c it has one more complement receptor

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

IgG4

A

binds with intermediate affinity

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

CD16

A

CD marker (Fc receptor for IgG)

located on NK cells, monocytes/macrophages and granulocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
CD32
``` CD marker (Fc receptor of IgG) located on B cells (feedback inhibition), monocytes/macrophages and granulocytes ```
26
CD64
Fc Receptor for IgG | located on monocytes and macrophages
27
IgA
can have a J piece that binds secretory peptides (produced by epithelial cells) primary antibody in external secretions (saliva, tears, mucus, bronchial, GU, digestive tracts) Mucosal immunity*** Primary antibody for the entry point of antigens that you are exposed to through your mucosa Polymeric-4 binding sites Very important in baby immunity (breast milk)
28
IgE
Low conc. in serum, very short half life Binds to basophils and tissue mast cells by Fc receptors with very high affinity Asthma, hay fever, peanut allergies Helminth infections
29
CD23 a and CD23b
Fc receptor for IgE located on mast cells and blood basophils
30
IgD
not usually in serum usually in monomeric form present as an Antigen specific receptor on mature B cells
31
IgM and IgD on surface of B cells have what in common?
have same specificity have the exact same complementary determining regions (CDR's, aka idiotope, hypervariable region)
32
Antigens
foreign molecules that bind to an antibody or TCR ***whether or not they induce an immune response
33
Immunogens
Antigens that induce an immune response
34
Epitope
part of the Ag that contacts the Ag-binding sites of an Ab or TCR. this is what binds the idiotope aka antigenic determinate
35
Pathogen
organism that causes disease
36
Haptens
small molecular weight molecules that can bind to an antibody but must be attached to a large carrier macromolecule to stimulate an immune response specific for the small molecule these are used in vaccination also seen in allergies (penicillin)
37
Endogenous antigens
autoantigens- self antigen (autoimmune diseases) alloantigens--> tissue specific antigen, present in one individual of a species but not in others (ABO) Intracellular pathogens--> viruses, intracellular bacteria and parasites (chlamydia)
38
Exogenous antigens
enter the body or system and freely circulate in the body fluids and are trapped by APC's allergens--> immunogen Microbial Iatrogenic--> doctor induced
39
Factors influencing immunogenicity (whether something is immunogenic or not)
Molecular mass Foreignness - usually only responds to non self Chemical composition- more complex, more immunogenic Physical form- particulate (more immunogenic) vs. soluble, denatured (more immunogenic) vs. native form Degradability- Ags more easily phagocytosed are more immunogenic Genetic factors- immunological repertoire Age- very young and very old Method of administration (dose, route, adjuvants)
40
Chemical nature of immunogens
Proteins- vast majority, good immunogens Polysaccharides- good immunogens Nucleic acids- poorly immunogenic, but can be immunogenic when complexed with proteins or single stranded (like viruses) Lipids-non-immunogenic usually, but may be happens
41
what determines the size of the epitope?
The size of the antigen binding site on the Ab
42
Epitopes recognized by B cells
B cell interaction with antigens is highly dependent upon the 3-D conformation of the antigen (so don't have to see things in a linear manner) epitopes can be associated with both soluble or particulate immunogens epitopes are usually exposed on the cell surface
43
Epitopes recognized by T cells
Only see primary sequence of amino acids in proteins (so not polysaccharides or nucleic acids) so don't need epitope on surface, b/c the T cell usually only see size 8-15 amino acid sequence on degraded smaller peptides DO NOT recognize free peptides or soluble antigens have to see peptides that are presented to them in bound to MHC (HLA) molecules
44
Epitope properties recognized by B cells
Accessible hydrophilic mobile peptides containing sequential or nonsequential amino acids
45
Epitope properties recognized by T cells
Internal linear peptides produced by processing of antigen and bound to MHC molecules
46
T dependent antigens
An Ag that requires both Th cells and B cells to stimulate an Ab response always proteins*** required for class switching of antibodies and affinity maturation
47
T independent antigens
Non protein Ag's (polysaccharides or lipids) stimulate antibody response without T help Usually identical epitopes that can cross-link BCR
48
Mitogens
Substances that cause cells (lymphocytes) to undergo cell division
49
LPS
a mitogen activator of human B cells (does not need t cell help)
50
Superantigens
Antigens that activate a large fraction of the T cells these are not processed but bind directly to MHC class II molecules and Vbeta of the TCR diseases that happen from these are in part due to hyper-activation of the immune system and subsequent release of biologically active cytokines by activated T cells
51
Ab/Ag Binding
form non-covalent bonds (H bonds, electrostatic, Van der waals, hypdrophobic) reversible interaction
52
Affinity
the strength with which one Ag-binding surface of an antibody (idiotope) binds to one epitope of an antigen
53
Avidity
Each antibody molecule can bind 2 to 10 epitopes of an antigen (depending if its IgA, IgM... etc.) or epitopes on two or more neighboring antigens. The total strength of binding is much greater than the affinity of a single antigen-antibody bond
54
The avidity of an Ab for its Ag is dependent on...
the affinities of the individual Ag combing sites
55
how are hapten/carrier complexes used in drugs...
drugs alone are poor stimulators of immune responses due to simple/small structure so.... these drugs form hapten-carrier complexes by binding a protein that is not immunogenic in free form basis for many drug allergies
56
Monoclonal antibodies
antibodies derived from a single B cell clone using this means that monoclonal antibodies against virtually any antigen can be produced
57
how do you make monoclonal antibodies
isolate spleen cells from mouse immunized with antigen X (Some of these are producing anti-X Ab) fuse spleen cells with immortal myeloma cell line Culture in medium only fused cells (hybridomas grow) select hybridomas that are producing monoclonal anti-X antibody
58
First drug for melanoma
Yervoy (Ipilimumab) this is a monoclonal antibody that downregulates the immune response ???
59
ELISA
coat wells with antigen of interest fill well with pt's fluid of interest if the pt's fluid of interest contains antibodies against specific antigen it will bind the wells are then washed... next second antibody is added specifc for first antibody also the second antibody has enzyme on it... next wash again to remove all unbound second antibody so next add substrate and if there is a color change then you know antibodies are present
60
Flow Cytometry
?
61
Recombinant antibodies
commonly used as therapeutic reagents in cancer immunotherapy

IHL Exam 2 (14 decks)

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