B Cells: Development Flashcards
(47 cards)
Where do the first 3 phases of B cell development happen?
Bone Marrow
Where do the last 3 phases of cell development and a little bit of the 3rd happen?
In the periphery
B cells are _______ and ______
- Diverse
2. Specific
T/F B cells are stockpiled in the lymphatic system
FALSE, they are NOT stockpiled but constantly replaced
How many B cells are made per day?
30 billion
What is the mature half life of a B cell?
50-100 days
Antibody repertoire of a B cell undergoes _______
Constant evolution
B cell populations are _____ at each phase
Winnowed (thinned out?)
In the bone marrow, what does the progression of a B cell look like?
- Stem cell
- Early pro-B cell
- Late pro-B cell
- Large pre-B cell
- Small pre-B cell
- Immature B cell
In the Secondary lymphoid organs and circulation what does the progression of a B cell look like?
- Immature B cell
- Mature Naive B cell
- Antigen-Activated B lymphoblast
- Antibody-Secreting plasma cell
- Memory cell
T/F Early and Late pro B-Cells are rich in immunoglobulin
FALSE, they have no immunoglobulin
What type of cell interactions drive B cell development?
Stromal cell
Stromal cells express ________ and __________
- Adhesion molecules
2. Growth factors
T/F Pro-B cells are programmed to die in the absence of survival signals
True
______ receptor expression changes with progression through developmental stages
B cell
At what stage in development does a B cell leave the bone marrow?
Immature B cell
What is happening in an Early pro-B cell regarding Heavy chain rearrangement?
- RAG proteins Activated
- Heavy chain D and J segments joined
- Occurs on both chromosomes
What is happening in a Late pro-B cell with regards to heavy chain rearrangement?
- Heavy chain V and DJ segments joined
- Occurs sequentially on chromosomes
- Two chances for rearrangement
What causes the transition from Pro to Pre B cell?
Pre-BCR signaling
T/F A functional heavy chain is produced by only one chromosome
True
*This is called Allelic exclusion
What does IgBeta signaling do in the checkpoint from pro to pre B cell?
- Checkpoint clearance
- Turns off RAG proteins
- Inintiates Cell division
- Allelic Exclusion
In the transition from Pro to pre B cell, what is happening with the Late Pro-B cell?
- VDJ rearrangement prodeucese pre-BCR
- Pre-BCR expressed in the ER
- Surrogate light chain expressed
- Igalpha/beta expressed
What would happen if you did not have allelic exclusion
Heterogenous B cell receptors with low-avidity binding
Each large pre-B cell becomes about how many small pre-B cells?
100
