Immunology 3

Question 1

What is another word for an immunoglobulin?

Answer 1

Antibody

Question 2

How many heavy chains exist in an immunoglobulin?

Answer 2

2

Question 3

How many domains are in a heavy chain of an immunoglobulin?

Answer 3

4, 3 constant and one variable

Question 4

How many domains are in a light chain?

Answer 4

2, 1 constant and 1 variable

Question 5

What are the two types of light chain?

Answer 5

lambda and kappa

Question 6

Roughly how many aa in light chain?

Answer 6

215

Question 7

Roughly how many aa in heavy chain?

Answer 7

450

Question 8

Roughly how many aa in each domain?

Answer 8

105/110

Question 9

How many disulphide bonds between heavy chains?

Answer 9

Variable! xxx

Question 10

Constant heavy genes are encoded by how many classes of gene?

Answer 10

5 –> alpha, Mu, gamma, delta, epsilon

Question 11

What are the different type of immunoglobin based on their heavy?

Answer 11

IgM
IgG
IgA
IgE
IgD

Question 12

In what way are immunoglobulin ‘bi-functional’?

Answer 12

• Vl and Vh regions recognise antigens

- The rest of molecule determines the biological activity, e.g. what cell it binds

Question 13

Can immunoglobulin activate complement?

Answer 13

Yes

Question 14

If you digest an immunoglobulin with papain what do you get?

Answer 14

Fab (fragment antigen binding) fragments

Question 15

How many hypervariable regions do Vl and Vh contain?

Answer 15

3 CDR regions

Question 16

On each arm of immunoglobulin how many CDRs are there?

Answer 16

6

Question 17

Roughly how many amino acids long is each CDR?

Answer 17

5-10

Question 18

Are CDRs in native immunoglobulins spatially or linearly very close?

Answer 18

Spatial, they are not close in the denatured polypeptide

Question 19

How many aa does the average the immunoglobulin ‘groove’ accommodate?

Answer 19

10 at most

Question 20

What is an epitope?

Answer 20

The region of the antigen recognised and bound by the antibody.

Question 21

Are epitopes

a) linear
b) discontinuous
c) either

Answer 21

epitopes can be either, primarily however they are discontinuous

Question 22

What is a multivalent antigen?

Answer 22

Antigen contains different epitopes

Question 23

Multivalent antigen with the same epitope are rare in protein antigens but common in WHAT?

Answer 23

Glycan antigens. One antibody type will bind multiple times.

Question 24

All epitopes and antibodies bind with the same affinity. True or False.

Answer 24

False

Question 25

What are monoclonal antibodies?

Answer 25

Antibodies that are all the same amino acids.

Question 26

What are polyclonal antibodies?

Answer 26

Antibodies made against an antigen that are a sum of different antibodies against lots of different epitopes.

Question 27

Are antibody/epitope interactions a) covalent b) non-covalent

Answer 27

non-covalent. High affinity is therefore achieved by precise shape complimentary for close interaction.

Question 28

Why do people try to get monoclonal antibodies?

Answer 28

they are very specific and so can be used in theraputics

Question 29

Why do you humanisie mouse antibodies?

Answer 29

In humans they will be recognised as foreign unless humanised. This step is not require these das as you engineer what you want.

Question 30

How many types of IgG are there?

Answer 30

4, IgG1, IgG2, IgG3, IgG4 | IgG1, IgG2a, IgG2b, IgG3

Question 31

C1q binding to antibodies trigger what?

Answer 31

complement cascade

Question 32

Which antibodies has good specificity for C1q?

Answer 32

IgG3

Question 33

Which antibodies can fix complement?

Answer 33

IgM, IgG3

Question 34

Which antibody is pentameric?

Answer 34

IgM

Question 35

How many constant heavy chain domains does IgM have?

Answer 35

4

Question 36

What is J chain?

Answer 36

A small protein required for polymerisation of IgM and IgA

Question 37

What are two configuration that a IgM pentamer can exist in?

Answer 37

Star configuration | or staple configuration where you get flexibility between c2 and c3 so all binding sites are on one surface

Question 38

What is the first antibody to be made after a pathogen is met?

Answer 38

IgM

Question 39

What is the second antibody to be made after a pathogen is met?

Answer 39

IgD

Question 40

Which immunoglobulin exists as a dimer with a J chain and a secretory component?

Answer 40

IgA

Question 41

What is the major antibody in the gut?

Answer 41

IgA

Question 42

What is the function of the secretory component in the IgA dimer?

Answer 42

Protects the immunoglobulin and makes it more stable. It is also part of the receptor used for translocating it from the inside to outside.

Question 43

What receptor does IgA bind to initiate transcytosis from basolateral membrane to apical membrane of epithelial cell.

Answer 43

poly-immunoglobulin receptor. | This receptor gets cleaved and a part of it remains bound to the IgA in the lumen

Question 44

What are subclasses IgA?

Answer 44

IgA1, IgA2

Question 45

Which immunoglobulin is involved in allegoric reactions?

Answer 45

IgE

Question 46

What is the receptor for IgE on mast cells called?

Answer 46

FCepsilon

Question 47

What does antibody crosslinking on mast cells cause?

Answer 47

Signal reduction and the mast cell, which is full of granules, to release mediators such as histamine and other substances that mediate allergic reactions.

Question 48

What is the general term for receptors that bind immunoglobulins?

Answer 48

Fc receptors

Question 49

FCgamma receptor 1 binds WHAT?

Answer 49

IgG1 and IgG3

Question 50

What do Fc receptors on phagocytes trigger?

Answer 50

phagocytosis (up take and destruction of antigen coated pathogens)

Question 51

There are some activating an inhibitory Fc receptors. What domain do the inhibitory receptors contain?

Answer 51

ITIM (immunoreceptor tyrosine based inhibitory motif) domain on the cytoplasmic side

Question 52

Fc receptors are often a) homodimer b) heterodimer

Answer 52

heterodimer. | alpha and gamma chains for example

Question 53

What is the net affinity of a polyclonal antibody defined by?

Answer 53

The sum of all the antibody's affinity for the different epitopes