L4-Immunoglobulin Structure

Question 1

What are the 5 types of immunoglobulin heavy chains?

Answer 1

mu - IgM
gamma - IgG
epsilon- IgE
alpha - IgA
delta- IgD

Question 2

What are the light chains?H

Answer 2

kappa and lamda

Question 3

Where is the antigen binding site in an immunoglobulin?

Answer 3

Variable region of heavy chain and light chain

Question 4

Describe the antibody structure

Answer 4

2 identical light chains paired with 2 identical heavy chains. Heavy chains bonded by disulfide bridge

Question 5

What makes up the Fab?

Answer 5

Antigen binding site

Light chain + 1/2 heavy chain

Question 6

What makes up the Fc?

Answer 6

Constant region of heavy chain

Question 7

Which antibodies are polymeric?

Answer 7

IgM: pentamer in blood serum with J chain
IgA: dimeric in mucosal secretions with J chain and secretory component

Question 8

What half of the Ig is the constant domain?

Answer 8

C-terminal

Question 9

What half of the Ig is the variable domain?

Answer 9

N-terminal

Question 10

Which Ig is predominant in 2ndary response?

Answer 10

IgG

Question 11

Which Ig is in external secretions?

Answer 11

IgA

Question 12

Which Ig is predominant in primary response?

Answer 12

IgM

Question 13

What Ig is mainly found on B cell surfaces?

Answer 13

IgD

Question 14

Which Ig is involved in allergic hypersensitivities

Answer 14

IgE

Question 15

Why is IgM so much heavier than all the other antibodies?

Answer 15

Due to pentameric structure

Question 16

What Ig functions as a B-cell Ag receptor along with IgM?

Answer 16

IgD

Question 17

Which antibody can transport across the placenta

Answer 17

IgG1- thisis how babies get maternal IgG

Question 18

What Ig is usally in membrane form and has very few plasma cells?

Answer 18

IgD

Question 19

What Ig fixes to mast cells and basophils via Fc receptors?

Answer 19

IgE

Question 20

Which Ig has a key role in mucosal immunity?

Answer 20

IgA

Question 21

What are the ways in which antibodies function?

Answer 21

Neutralization
Opsonization
Sensitize for killing by NK cells
Sensitize to mast cells
Activate complement system

Question 22

How can you tell which antibody is which?

Answer 22

Can't use electrophoresis- all same
Use antibodies that target the constant regions of each subclass of antibodies

Question 23

What happens to mast cells if IgE binds?

Answer 23

No antigen: nothing happens

Yes Antigen: recognized by Fab of IgE -> cross linking as Fc receptor of mast cell binds IgE

Question 24

Hyow can antibodies promote destruction of a pathogen?

Answer 24

Neutralize or promote by activating other effector mechanisms like complement or Fc receptor mediated killing

Question 25

What kind of Ab is present just before birth and how?

Answer 25

IgG from maternal contribution. High levels just before birht and decays as half life is 3 weeks

Question 26

What Ab is produced when a neonate is born?

Answer 26

IgM

Question 27

Why is the 6-9 month mark considered the critical time?

Answer 27

Low maternal IgG levels and not enough Ig produced by baby yet

Question 28

When are adult levels of IgM reached? IgA? IgG?

Answer 28

IgM: 10 months IgG: 4 years IgA: 10 years

Question 29

What is polyclonal antibody?

Answer 29

found in serum of immunized people in which different antibodies are present that are directed against different epitopes and are made from different B cells

Question 30

WHat is monoclonal antibodies?

Answer 30

Antibodies from 1 clone of B cells all targeting the same epitope of the same antigen

Question 31

What is an example of a polyclonal antibody treatment?

Answer 31

IVIG: take blood from people and pool it and use to treat many diff problems

Question 32

What is an example of a monoclonal antibody treatment?

Answer 32

Tumor specific antibodies

Question 33

What are the gene components of the light chain and heavy chain?

Answer 33

Light: VJ + constant Heavy: VDJ + constant

Question 34

What is the process in which Ig genes as well as TCR genes go through to create their receptors/antibodies?

Answer 34

Somatic DNA REcombination

Question 35

What is the process in which Ig genes as well as TCR genes go through to create their receptors/antibodies?

Answer 35

Somatic DNA REcombination

Question 36

WHat is the order of Ig gene rearrangement in B cell?

Answer 36

Heavy Chain: DJ Heavy Chain: VDJ Light Chain: VJ Assembly of IgM

Question 37

Where does B cell development and Ig gene rearrangement take place?

Answer 37

Bone marrow

Question 38

Is Ig gene rearrangement antigen driven?

Answer 38

No. It is random

Question 39

What happens to gene segments in between ?

Answer 39

They are lost and deleted as BRECs

Question 40

How do you get the new VDJ or VJ genes near the constant region C genes?

Answer 40

RNA splicing of the primary RNA transcript = gets rid of introns