Pod: Antibody Structure And Diversity

Front 1

What does multivalent antigen mean?

Back 1

It has multiple epitopes(same or different type) and thus several antibodies can bind.

Front 2

What is a hapten?

Back 2

Low MW. Not immunogenic unless conjugated to a carrier.

Front 3

What does immunogen do?

Back 3

induce antibody formation.

Front 4

Which two types of antibodies don't have the hinge region thus have low affinity toward antigens?

Back 4

IgM and IgE

Front 5

Idiotype corresponds to which region of the immunoglobulins?

Back 5

V region of both H and L chains.

Front 6

Allotype corresponds to which region of the immunoglobulins?

Back 6

C region of both H and L chain. Genetic variation between members of the same species expressed on H and L chains.

Front 7

Isotype corresponds to which region of the immunoglobulins?

Back 7

Only C region of the H chain.
IgM, IgG, IgA, IgD, IgE.
specific effector functions.

Front 8

Hypervariable Regions/complementary-determining regions (HV/CDR), where are they located?

Back 8

3 loops on each H and L chain. 1st and 2nd loop in the V region and the 3rd in the VJ junction of L chain and V-DJ junction of H chain.

Composite HV sites increases diversity and speciticity.

Front 9

T/F
Each epitope can be bound by different antibodies.

Back 9

T

Front 10

Types of antigen-antibody binding forces:

Back 10

noncovalent
electrostatic forces (salt bridge)
H bond
Vander Waals
hydrophobic interactions

Front 11

Types of epitopes:

Back 11

pocket
cleft
discontinuous

Front 12

What are polyclonal antobodies specific for?

Back 12

Antigen and anything else in antigen prep.

Front 13

what are monoclonal antibodies specific for?

Back 13

single antibody for a specific antigen.

Front 14

The problem of using mouse monoclonal antibody as therapeutics is allotype problem. What's one way of reducing the effect?

Back 14

Replace human HV/CDR loops with mouse HV/CDR loops.

Front 15

Differences between H and L somatic rearrangement:

Back 15

L: single rearrangement
one C region: κ,λ
H: two rearrangements
one C region: υ,δ,γ,ε,α

Front 16

What are the two types of recombination signal sequence (RSS)?

Back 16

heptamer
nomamer

Front 17

What are the different spacers and what rules apply for the rearrangement?

Back 17

spacer length: 23, 12

recombination only occurs between different RSS and different spacers.

Front 18

What is 12/23 rule?

Back 18

one RAG bind to 12bp spacer and the other one bind to 23bp spacer.

Front 19

What stages in B cell development are RAG1 and RAG2 active?

Back 19

Early Pro-B cell:DJ rearrange
Late Pro-B cell:V-DJ rearrange
Small Pre-B cell:VJ rearrange

Front 20

What stages in T cell development are RAG1 and RAG2 active?

Back 20

CD25+CD44low stage (pre-TCRDJ): rearrange, V-DJ rearrange

double positive stage: VJ rearrange

Front 21

DNA that is excised between recombined V and J segments forms a joint called:

Back 21

signal joint

Front 22

Broken chromosome DNA V and J segments joined by DNA ligase IV forms a joint called:

Back 22

coding joint

Front 23

List enzymes involved in making the coding joint(CDR3):

Back 23

1.RAG cleaves RSS,P nucleotides created
2. TdT adds N nucleotides
3. paring of nucleotides
4. removal of unpaired nucleotides
5. gaps are filled in by DNA synthesis and ligation

Front 24

When is TdT active during B cell development?

Back 24

Heavy chain rearrangement and half of light chain rearrangemnt.

Front 25

Explain allelic exclusion.

Back 25

Successful rearrangment of H or L chain on one chromosome inhibit rearrangement of the other chromosome.

Adds diversity to antigen determinant.

Front 26

T/F: C region of IgM and IgD is the result of DNA rearrangement.

Back 26

F. Alternative splicing at imature B cell stage to become mature B cell.

Front 27

Do IgM and IgD on the same naive B cell have the same idiotype?

Back 27

Yes. C region alternative splicing is after V region rearangment.

Front 28

What associated membrane-bound Igs do BCRs have?

Back 28

Igα:Igβ

Front 29

What associated membrane-bound Ig do TCRs have?

Back 29

CD3:ε,γ,ς,δ

Front 30

What is the function of invariant chain Igα:Igβ?

Back 30

1. Help move BCR to surface.
2. Signal transduction because of long cytoplasmic tails:
1) B cell activation
2) B cell proliferation and differentiation after antigen binding.

Front 31

Which two of the following processes happen after B cell activation by antigen binding?
A. Alternative splicing to retain hydrophilic tail of Ig to get secreted out.
B. Somatic hypermutation
C. H chain rearrangement
D. L chain rearrangement
E. Alternative splicing of C region to make either membrane bound IgM or IgD.

Back 31

A. B.

Front 32

Which of the following method of diversifying CDR3 happens after B cell activation?
A. P nucleotides
B. Allelic exclusion
C. Somatic hypermutation
D. Genetic rearrangement

Back 32

C.

Front 33

What enzymes are involved in somatic hypermutation?

Back 33

AID: change cytidine to uracil
UNG: remove uracil
works only on single stranded DNA

affinity maturation

Front 34

Which two of the following heavy chain C region has 4 domains?
A.υ
B.δ
C.γ
D.ε
E.α
E.

Back 34

A. D.

Front 35

Where are the plasma cells secreting IgM located?

Back 35

lymph nodes
spleen
bone marrow

Front 36

What pathogens do IgM strongly bind?

Back 36

pathogens with repetitive epitopes: LPS on bacterial cell wall

Front 37

What are the major functions of IgM?

Back 37

1)neutralization of antigen
2)activation of complement which kills microorganism directly or facilitates pahgocytosis.

Front 38

Pentameric IgM is held together by____?

Back 38

J chain (not J segment) and disulfide linkage.

Front 39

What enzymes are used during class switch?

Back 39

AID
UNG

only occurs during active immune response.

Front 40

Igs specialized for neutralization:

Back 40

++:IgG, IgA
+:IgM

Front 41

Igs specialized for opsinization:

Back 41

+++:IgG
+:IgA

Front 42

Igs specialized for complement activation:

Back 42

+++: IgM, IgG3
++: IgG1
+: IgG2, IgA

Front 43

What are the two secretory Igs that cross epithelial membrane?

Back 43

IgA, IgM

Front 44

Which Ig can cross placental barrier?

Back 44

IgG

Front 45

What are the main function of IgG?

Back 45

opsinization
complement activation: IgG1,3

Front 46

Fc receptors for IgE are found mainly on what cells?

Back 46

mast cells
basophils
eosinophils

Front 47

What type of microorganism does IgE tag?

Back 47

parasites, worms, allergens.

Front 48

Which Ig is made most abundent?

Back 48

dimeric IgA joined by J-chain similar to IgM.

Front 49

Where is IgA concentrated in the body?

Back 49

mucosal surface of GI tract.
milk, saliva, sweat, tears.