Fine Structure of Antibodies

Question 1

Which two domains of the Fc portion do not interact and why?

Answer 1

The two Ch1 portions of the heavy chain

Question 2

Which regions of the V region actually interact with the epitope?

Answer 2

The hypervariable

Question 3

What are hyper-variable regions also known as?

Answer 3

Complementarity-determining regions

Question 4

How many CDRs are found per antibody?

Answer 4

12

Question 5

How many framework regions are in each V region?

Answer 5

4

Question 6

What are the two types of L chains?

Answer 6

kappa and lambda

Question 7

True or False. L chains do not need to be identical in an antibody.

Answer 7

False, they do need to be identical

Question 8

Is there effector function associated with the L chain?

Answer 8

No

Question 9

IgG is divided into how many subclasses?

Answer 9

4

Question 10

IgA is divided into how many subclasses?

Answer 10

2

Question 11

What type of bond forms loops within each chain?

Answer 11

Intrachain S-S

Question 12

Which region of the antibody determines function and anatomical location?

Answer 12

The Ch region

Question 13

IgM is predominately present as what?

Answer 13

A monomeric membrane-bound BCR on mature B cells

Question 14

Which isotype is the first secreted when B cells are activated by T cells?

Answer 14

IgM

Question 15

Which isotype is the most predominant in response to T-independent antigens?

Answer 15

IgM

Question 16

What formation is IgM commonly found in?

Answer 16

Pentamer

Question 17

Which isotype is the most efficient in activating the classical complement pathway?

Answer 17

IgM

Question 18

What is the major source of IgM in saliva?

Answer 18

Gengival cervicular fluid

Question 19

Which isotype is the only kind made by the fetus?

Answer 19

IgM

Question 20

How many subclasses of IgG are found in humans?

Answer 20

4

Question 21

Which region of the antibody helps to distinguish between the classes?

Answer 21

The hinge region

Question 22

Which isotype is the most abundant in tissues and serum?

Answer 22

IgG

Question 23

Which isotype can cross the placenta?

Answer 23

IgG

Question 24

Rank the subclasses of IgG in order of effectiveness of crossing the placenta

Answer 24

IgG1 > IgG3 > IgG2 > IgG4

Question 25

Which subclasses of IgG activate the complement pathway?

Answer 25

IgG1, IgG2, and IgG3

Question 26

How can IgG be bound?

Answer 26

By Fc receptors

Question 27

What is the purpose of binding IgG on various cell types?

Answer 27

To increase opsonization

Question 28

Which isotype can participate in ADCC?

Answer 28

IgG

Question 29

How many subclasses of IgA are there?

Answer 29

2

Question 30

Which subclass of IgA is predominant in serum and in what ratio?

Answer 30

IgA1 in a 5:1 ratio

Question 31

What is the ratio of IgA1:IgA2 in mucosal secretions?

Answer 31

1:1

Question 32

What is IgA1 predominantly directed against?

Answer 32

Protein Isotopes

Question 33

What is IgA2 directed against?

Answer 33

Polysaccharide isotopes

Question 34

Which isotype is most abundant of all the isotypes?

Answer 34

IgA

Question 35

What is the most abundant isotype in secretions?

Answer 35

IgA

Question 36

Where is monomeric IgA found?

Answer 36

In serum

Question 37

Where is polymeric IgA found?

Answer 37

In secretions as in dimer form (SIgA)

Question 38

How is most IgE found?

Answer 38

Bound to Fce receptors on the surface of mast cells, basophils, and easinophils

Question 39

What happens when Fabs of IgE are cross-linked by binding antigen?

Answer 39

The cell is activated and releases contents of its granules.

Question 40

When does IgE release contents of its granules?

Answer 40

When it's Fabs are cross-linked in antigen binding

Question 41

What is an example of immediate hypersensitivity reactions mediated by IgE?

Answer 41

Type 1 hypersensitivity or allergy

Question 42

How does IgE provide protection from parasites?

Answer 42

When repeating epitopes on the parasite cause cross-linking and granules contents from the attached cell to be released onto the parasite killing it

Question 43

Where are most IgE secreting plasma cells found?

Answer 43

In the pharyngeal tonsils.

Question 44

Where is IgD mostly found?

Answer 44

On the surface of naive mature B cells

Question 45

How does IgD function in B cell activation?

Answer 45

As a BCR

Question 46

How does IgD play a role in regulation of B cell surface?

Answer 46

If IgD is missing, self-reactive B cells can enter lymphoid organs and proliferate