Quiz 5 - German - B Cell Development Flashcards
Tell me the B cell development timeline including the heavy and light chain designations.
Bone Marrow
Stem cell - germline, germline Early pro-B - germline, germline Late pro-B - DJ, germline Large pre-B - VDJ, germline Small pre-B - VDJ, germline Immature B cell - VDJ, VJ
Lymphoid organs/circulation
Immature B cell (IgM, no IgD) Immature B cell (High IgM, low IgD) Mature, naive B cell (Low IgM, High IgD) Antigen activated B lymphoblast Antibody-secreting plasma cell Memory cell
Are B cells stockpiled?
NAH TRICK
30 billion/day
Mature half-life: 50-100 days
T/F - There is no immunoglobulin expressed during both the pro-B cell phases.
TRUE
Where is the checkpoint for the functional heavy chain?
B/t late pro-B cell and large pre-B cell
Where is the checkpoint for the function light chain?
B/t small pre-B cell and immature B cell
What drives B cell development?
Stromal cell interactions
Stromal cells express ___________ molecules and ___________ factors.
Adhesion
Growth
What is the event that moves the development of a B cell from early pro to late pro?
Once D and J have rearranged on chromosomes
*Once in late, V-DJ are rearranged on the first chromosome
Tell me three things about the early pro B cell.
RAG proteins activated
Heavy chain D and J segments joined
Occurs on both chromosomes
Tell me three things about the late pro B cell.
Heavy chain V and DJ segments joined
Occurs sequentially on chromosomes
2 chances for rearrangement
___-_____ signaling causes the transition from pro to pre B cell.
Pre-BCR
What is allelic exclusion?
Functional heavy chain produced by only one chromosome
Tell me about late pro-B cell in terms of pre-BCR.
VDJ rearrangement produces pre-BCR
Pre-BCR expressed in the ER
Surrogate light chain expressed
IgAlpha/Beta expressed
Tell me about IgBeta signaling.
Checkpoint clearance
Turns OFF RAG proteins
Initiates cell division
Allelic exclusion
What is affinity?
What is avidity?
Affinity - Likelihood of binding
Avidity - Strength of binding