Ontogeny of the IS

Question 1

What is the Bursa of Fabricius and its human equivalent?

Answer 1

It is where the b-cells mature in chickens.

Its Bone in humans

Question 2

True/False only the Heavy chain of an antibody has a VDJ region.

Answer 2

True.

The light chain has a V-J region but no D.

Question 3

What are the different hallmarks of B cell maturation?

Answer 3

1. Production of -mu- protein in “pro B cell”
2. Cytoplasmic IgM (cIgM). mu + lambda or kappa light chain in “Pre B cell”
3. Immature B Cell puts in a sIgM (surface receptor)
4. Mature B cell adds sIgD after clonal deletion (self reactive destruction of B cells)

Question 4

Describe “switch recombination.”

Answer 4

When IgM is activated, helper T cells tell B cell to “switch” antibody production from Mu-> G or A or E.

Question 5

How does IgG cross the placenta?

Answer 5

Via Active Transport.

Question 6

When does a baby start producing IgG

Answer 6

Around 3 months.

Question 7

Which would be more concerning, a baby with anti-rubella antibodies that are IgG or IgM

Answer 7

IgM

IgG would be from the mother.

Question 8

What is the age at which people can usually reconstitute their t cell numbers and diversity?

Answer 8

Old people have fewer but larger clones than the young. They have more memory and less naïve cells.

Old people respond well to antigents they’ve seen in the past and not to new ones.