Antibodies II Flashcards
(14 cards)
What do alpha, gamma, delta, epsilon, and mu stand for?
Constant domains for IgA IgG IgD IgE IgM
What is the common structure of Immunoglobulin domains?
2 or more Beta-pleated sheets arranged in oppo direction that are stabilized by disulfide bonds
What are some fun facts about IgM?
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
What are some fun facts about IgG?
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
What are some fun facts about IgA
In breast milk
- B cells that produce IgA migrate to the sub-epithelial tissue of most mucosal epithelia and of glandular epithelia
What are some fun facts about IgE?
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
What are some ways to produced Ab diversity?
- Mixing and matching of various gene segments for heavy and light chains
- Variation incorporated at joining sites for various segments of heavy and light chains
- Hypermutation of variable regions during B cell proliferation
- mixing and matching heavy and light chains
What is the clonal selection theory?
Each cell of the immune system are programmed to make only one antibody
- T cells too
- Random and not dependent on outside world
Each person has 2 different allotypes but does each B cell express heavy chains from both ma and pa for example?
NO
- One B-cell has 1 H chain and 1 L chain. The other genes are silenced
What is recombination?
Changing the relative positions of 2 pieces of DNA
What are the gene segments for H chain and L chains?
VDJ gene for heavy
VJ gene for light
When can Kappa rearrangement proceed?
after heavy chain has been successful
- if kappa fails then lambda can be tried
What is RAG recombinase?
Enzymes that do the recombination of Ab and T cells receptor DNA
What is Omenn Syndrome?
When RAGs are knocked out. One cannot make either B and T cells
