Antibodies II

Question 1

What do alpha, gamma, delta, epsilon, and mu stand for?

Answer 1

Constant domains for 
IgA
IgG
IgD
IgE
IgM

Question 2

What is the common structure of Immunoglobulin domains?

Answer 2

2 or more Beta-pleated sheets arranged in oppo direction that are stabilized by disulfide bonds

Question 3

What are some fun facts about IgM?

Answer 3

Not present in interstitial fluids

• not useful in protecting immunocompromised individuals
• elevated levels indicate a recent infection or other exposure to Ag
• DOES NOT bind to macs Fc Receptors

Question 4

What are some fun facts about IgG?

Answer 4

DOES bind to macs Fc receptors

• mediate hemolytic disease in newborn
• useful in protecting immunocompromised individuals
• Used as blocking Ab to block TNF production (in RA)
• present in interstitial fluids
• Used as blocking Ab against allergens

Question 5

What are some fun facts about IgA

Answer 5

In breast milk

- B cells that produce IgA migrate to the sub-epithelial tissue of most mucosal epithelia and of glandular epithelia

Question 6

What are some fun facts about IgE?

Answer 6

Allergies to certain Ags leads to over production of IgE in individuals
- Type 1 hypersensitivity (allergic reaction) resulting from Ag present and many mast cells degranulated

Question 7

What are some ways to produced Ab diversity?

Answer 7

1. Mixing and matching of various gene segments for heavy and light chains
2. Variation incorporated at joining sites for various segments of heavy and light chains
3. Hypermutation of variable regions during B cell proliferation
4. mixing and matching heavy and light chains

Question 8

What is the clonal selection theory?

Answer 8

Each cell of the immune system are programmed to make only one antibody

• T cells too
• Random and not dependent on outside world

Question 9

Each person has 2 different allotypes but does each B cell express heavy chains from both ma and pa for example?

Answer 9

NO

- One B-cell has 1 H chain and 1 L chain. The other genes are silenced

Question 10

What is recombination?

Answer 10

Changing the relative positions of 2 pieces of DNA

Question 11

What are the gene segments for H chain and L chains?

Answer 11

VDJ gene for heavy

VJ gene for light

Question 12

When can Kappa rearrangement proceed?

Answer 12

after heavy chain has been successful

- if kappa fails then lambda can be tried

Question 13

What is RAG recombinase?

Answer 13

Enzymes that do the recombination of Ab and T cells receptor DNA

Question 14

What is Omenn Syndrome?

Answer 14

When RAGs are knocked out. One cannot make either B and T cells