Exam II - Antibodies

Question 1

Which types of cells produce antibodies?

Answer 1

Plasma cells

Question 2

What type of globulins are Ab?

Answer 2

Gamma globulins

Question 3

During which phase of the immune response are Ab produced?

Answer 3

recognition phase and effector phase

Question 4

What class of Ab has the least carbohydrate?

Answer 4

IgG

Question 5

How many heavy & light chains make up an Ab?

Answer 5

one heavy chain, one light chain

Question 6

How many C and V regions does the light chain possess?

Answer 6

1 C region, 1 V region

Question 7

How many C & V regions does the heavy chain possess?

Answer 7

3 C region, 1 V region

Question 8

Where is the hinge region located?

Answer 8

On the heavy chain between the CH1 and CH2 regions

Question 9

Which Abs do not possess hinge regions?

Answer 9

IgM and IgE

Question 10

What is the bifunctional nature of Ab?

Answer 10

Antigen recognition and effector functions are spatially separate from each other

Question 11

Where does papain cleave an Ab?

Which fragments remain?

Answer 11

Papain cleaves IgG above the -S-S bond at the hinge region

2 Fab segments and 1 Fc segment

Question 12

Where does pepsin cleave an Ab?

Which fragments remain?

Answer 12

Pepsin cleaves below the -S-S bond at the hinge region, so the interchain disulfide bonds are retained in the F(ab’)2 molecule, though the Fc fragment is degraded

Question 13

Define hypervariable region

Answer 13

the hypervariable regions are sites within the V light and heavy regoins where the amino acid sequences are highly variable

Question 14

hypervariable regions are also known as:

Answer 14

Complementarity-determining regions (CDR)

Question 15

Which CDR is the most variable?

Answer 15

CDR3 of the variable regions on heavy & light chains

Question 16

What is Ag-Ab binding characterized by?

Answer 16

non-covalent, reversible binding

Question 17

Define avidity

Answer 17

the strength of the binding between one Fab fragment of Ab and an epitope of an antigen

Question 18

Which Ab class demonstrates the highest Avidity?

Answer 18

IgM (pentameric)

Question 19

When can Ab act as Ags ?

What are they called in this situation?

Answer 19

When they’re introduced to a foreign host

Anti-antibodies

Question 20

Define isotype

Answer 20

refers to the antigenic differences in the C and Ch regions

Question 21

Define allotype

Answer 21

additional antigenic features of Cl and Ch regions that vary among individuals (establish paternity)

Question 22

Define idiotype

Answer 22

antigenic determinants formed by the amino acids in the hypervariable regions

Question 23

What is the primary function of an Ab?

Answer 23

to bind to an antigen

Question 24

Where and when is IgG found primarily?

Answer 24

found in blood, tissue spaces, and extravascular spaces. It is found in response to the secondary immune response and is the major Ig in serum

Question 25

List the 3 FcγRs

Answer 25

FcγRI, FcγRII, FcγRIII

Question 26

Can IgG cross the placenta?

Answer 26

Yes, but not in all species

Question 27

List 2 of the effector functions of IgG

Answer 27

opsonization and neutralizatoin via complement activation

Question 28

Why is IgM the most efficient Ig in agglutination and complement activation?

Answer 28

because it has the most Fabs, and has the highest avidity

Question 29

Where in the body is IgM found?

Answer 29

serum

Question 30

What is elevated IgM in the neonate blood indicative of?

Answer 30

transplacental infection

Question 31

In what form is sIgA found?

Answer 31

dimeric form

Question 32

Where does IgA acquire it secretory component?

Answer 32

It is synthesized by epithelial cells

Question 33

What are the functions of sIgA?

Answer 33

protection of mucous membranes

Question 34

To what does the Fc portion of IgG bind?

Answer 34

To receptors on the placenta, lymphocytes

Question 35

Which Ab are heat liable?

Answer 35

IgE & IgD

Question 36

IgE is predominantly associated in immune response to *which two things*?

Answer 36

Allergic reactions and parasitic infections

Question 37

What is the function of IgD?

Answer 37

Antigen receptor along with IgM on naive B cells

Question 38

Which cells can express IgD?

Answer 38

naive B cells

Question 39

What types of Ab results from Ag injection into an animal?

Answer 39

polyclonal antibodies

Question 40

What do we call Ab that arise from a single clone cell?

Answer 40

monoclonal antibodies

Question 41

Which two cell types are fused together for the production of monoclonal Ab?

Answer 41

myeloma cell and a normal B cell

Question 42

\_\_\_\_\_\_\_\_\_\_\_\_\_\_ is the only function of Igs mediated *exclusively* by Fab binding of antigen and does not require participation of the C_H regions

Answer 42

**_neutralization_** is the only function of Igs mediated exclusively by Fab binding of antigen and does not require participation of the CH​ regions

Question 43

Which Fcγ receptor is found on B cells?

Answer 43

FcγRII (CD32)