b cell development

Question 1

Common lymphoid progenitor

Answer 1

E2A and EBF important for B cell commitment

Question 2

Early pro-B cell

Answer 2

heavy chain rearrangement (D-J)

Question 3

Late pro-B cell

Answer 3

V-DJ rearrangement

Question 4

Large pre-B cell

Answer 4

mu chain paired with lambda 5 and VpreB (surrogate light chain)
expressed to see if it crosslinks
if it does, Bruton’s tyrosine kinase acts as positive signal
allelic exclusion + proliferation

Question 5

small pre-B cell

Answer 5

light chain rearrangement
isotypic exclusion (picks either kappa or lambda)

Question 6

central tolerance

Answer 6

Four main outcomes for an immature B cell leaving the bone marrow
No self-reaction
Multivalent self-molecule: apoptosis
Soluble self-molecule: anergic
Low affinity non-cross linking self-
molecule: ignorant

Question 7

receptor editing

Answer 7

Rescues self-reactive B cells from clonal deletion
- RAG expression is still active at this stage
○ Light chain rearrangements

Question 8

maturation of b cells

Answer 8

receives positive signals from follicular dendritic cells
- specifically BAFF
also needs weak BCR interactions

Question 9

peripheral tolerance

Answer 9

same outcomes as central tolerance