Antibodies- Diebel

Question 1

What are the two flavors of light chains?

Answer 1

Kappa

Lambda

Question 2

Does the type of light chain change during class switching?

Answer 2

NO!!!! Stays the same

Question 3

What part of the antibody is changing during class switching?

Answer 3

The heavy chain!

Question 4

How many types of heavy chains are there?

Answer 4

5

Question 5

What defines the class of an antibody?

Answer 5

The heavy chain

Question 6

How many isotypes are there?

Answer 6

aka as subtypes, there are 10

Question 7

Function of IgG?

Answer 7

most common in blood and tissue fluids

Neutralizes toxins
Does some complement activation

Question 8

Function of IgA?

Answer 8

Best for antiviral activity and toxin neutralization

Question 9

Function of IgM?

Answer 9

Best for bacterial lysis and complement fixation

**first antibody to appear in serum after immunization

Question 10

Function of IgE?

Answer 10

Mast cell/basophil degranulation

*responsible for type 1 hypersensitivity

Question 11

Function of IgD?

Answer 11

Functions mainly as receptor on naive B cells

Question 12

What do elevated levels of IgM indicate?

Answer 12

recent infection (haven’t class switched yet?

Question 13

What is the only antibody that can cross the placenta?

Answer 13

IgG

Question 14

What are the four ways antibody diversity is created?

Answer 14

1. Gene rearrangment
2. Variation incorporated at joining sights
3. Hypermutation of variable region
4. Mixing and matching of heavy and light chians

Question 15

What is the role of RAG recombinases?

Answer 15

Enzymes that do recombination of antibody DNA are RAG-1 and RAG2

Question 16

What are somatic mutaitons?

Answer 16

During production of V-D and D-J joints….

exonucleases chew away a few nucleotides and TdT adds a few nucleotides which doesn’t use templateA

Question 17

At what point of gene expression does class switching occur?

Answer 17

D/M to secretory M Occurs at the level of RNA splicing (processing of mRNA transcripts)

BUT

As they continue to divide and differentiate additional class switching from M to G,E or A occures at the level of DNA recombination