B cell development

Question 1

What are the two phases of b cell development?

Answer 1

Ag independent phase

Ag dependent phase

Question 2

Where does the Ag independent phase take place?

Answer 2

takes place in bone marrow (fetal liver or spleen)

Question 3

What is taking place in the Ag independent phase?

Answer 3

Ig gene rearrangment

Question 4

When does the Ag dependent phase takes place?

Answer 4

upon recognition of the Ag

Question 5

What happens in the Ag dependent phase?

Answer 5

proliferation
becomes memory or plasma cell
class switch (with tcell help)

Question 6

What are the steps in bcell development?

Answer 6

Ig gene rearrangement (90% die, test to see if self reactive)

movement to the periphery
(contact Ag)

development into plasma cell or memory cell

Question 7

What is the develepment pathway of a b cell in the Ag independent phase?

Answer 7

Stem cell 
pro b cell 
pre b cell 
immature b cell
Mature(naive) bcell

Question 8

What is a cell when it is a stem cell?

Answer 8

not committed to becoming a B cell

Question 9

What happens with a pro b cell?

Answer 9

B cell, H chain gene rearrangement
CD19, CD20, CD45R expression
Igα/Igβ, RAG1/RAG2, Tdt expre

Question 10

What happens with a pre b cell?

Answer 10

H chain with surrogate light chain on B cell surface

no Tdt expression

Question 11

What is cd20?

Answer 11

major b cell marker

Question 12

What happens in a immature B cell?

Answer 12

gene rearrangement complete, IgM expression,

moves to periphery once “complete”

Question 13

What happens in a Mature b cell?

Answer 13

IgM and IgD expression

Question 14

What happens when a mature b cell contacts a Ag?

Answer 14

Ag dependent phase and b cell activation