B Cells: Development

Question 1

Where do the first 3 phases of B cell development happen?

Answer 1

Bone Marrow

Question 2

Where do the last 3 phases of cell development and a little bit of the 3rd happen?

Answer 2

In the periphery

Question 3

B cells are _______ and ______

Answer 3

1. Diverse

2. Specific

Question 4

T/F B cells are stockpiled in the lymphatic system

Answer 4

FALSE, they are NOT stockpiled but constantly replaced

Question 5

How many B cells are made per day?

Answer 5

30 billion

Question 6

What is the mature half life of a B cell?

Answer 6

50-100 days

Question 7

Antibody repertoire of a B cell undergoes _______

Answer 7

Constant evolution

Question 8

B cell populations are _____ at each phase

Answer 8

Winnowed (thinned out?)

Question 9

In the bone marrow, what does the progression of a B cell look like?

Answer 9

1. Stem cell
2. Early pro-B cell
3. Late pro-B cell
4. Large pre-B cell
5. Small pre-B cell
6. Immature B cell

Question 10

In the Secondary lymphoid organs and circulation what does the progression of a B cell look like?

Answer 10

1. Immature B cell
2. Mature Naive B cell
3. Antigen-Activated B lymphoblast
4. Antibody-Secreting plasma cell
5. Memory cell

Question 11

T/F Early and Late pro B-Cells are rich in immunoglobulin

Answer 11

FALSE, they have no immunoglobulin

Question 12

What type of cell interactions drive B cell development?

Answer 12

Stromal cell

Question 13

Stromal cells express ________ and __________

Answer 13

1. Adhesion molecules

2. Growth factors

Question 14

T/F Pro-B cells are programmed to die in the absence of survival signals

Answer 14

True

Question 15

______ receptor expression changes with progression through developmental stages

Answer 15

B cell

Question 16

At what stage in development does a B cell leave the bone marrow?

Answer 16

Immature B cell

Question 17

What is happening in an Early pro-B cell regarding Heavy chain rearrangement?

Answer 17

1. RAG proteins Activated
2. Heavy chain D and J segments joined
3. Occurs on both chromosomes

Question 18

What is happening in a Late pro-B cell with regards to heavy chain rearrangement?

Answer 18

1. Heavy chain V and DJ segments joined
2. Occurs sequentially on chromosomes
3. Two chances for rearrangement

Question 19

What causes the transition from Pro to Pre B cell?

Answer 19

Pre-BCR signaling

Question 20

T/F A functional heavy chain is produced by only one chromosome

Answer 20

True

*This is called Allelic exclusion

Question 21

What does IgBeta signaling do in the checkpoint from pro to pre B cell?

Answer 21

1. Checkpoint clearance
2. Turns off RAG proteins
3. Inintiates Cell division
4. Allelic Exclusion

Question 22

In the transition from Pro to pre B cell, what is happening with the Late Pro-B cell?

Answer 22

1. VDJ rearrangement prodeucese pre-BCR
2. Pre-BCR expressed in the ER
3. Surrogate light chain expressed
4. Igalpha/beta expressed

Question 23

What would happen if you did not have allelic exclusion

Answer 23

Heterogenous B cell receptors with low-avidity binding

Question 24

Each large pre-B cell becomes about how many small pre-B cells?

Answer 24

100

Question 25

Going from Large to small pre-B cell what happens to the RAG genes?

Answer 25

They are reactivated

Question 26

T/F Each small pre-B cell has a unique recombination per cell

Answer 26

True

Question 27

In Light chain rearrangement, how many recombination attempts are there per chromosome?

Answer 27

4 to 5

Question 28

Approximately how many small pre-B cells survive?

Answer 28

85%

Question 29

Where are the two different checkpoints in B Cell development in the bone marrow?

Answer 29

1. Pre-B cell receptor - Selects for functional heavy chains 2. B-Cell receptor - Selects for functional light chains

Question 30

Immature B cells undergo __________

Answer 30

Negative selection

Question 31

Exposure to self antigen ensures _______

Answer 31

Tolerance

Question 32

What is Tolerace?

Answer 32

Inability to respond to self antigen

Question 33

What are the two types of Tolerance?

Answer 33

1. Central | 2. Peripheral

Question 34

What is Central tolerance?

Answer 34

Tolerance acquired in bone marrow

Question 35

What is Peripheral tolerance?

Answer 35

Tolerance acquired in the periphery

Question 36

What are the 3 fates of a B cell in negative selection?

Answer 36

1. Light chain reorganization 2. Apoptosis 3. Anergy

Question 37

What is Anergy?

Answer 37

Cells that are still alive but essentially shut down all their signaling and activating processes *Usually die after about 3-5 days

Question 38

Immature B cells migrate to ______

Answer 38

Lymphoid tissues

Question 39

Where to B cells mature?

Answer 39

In secondary lymphoid tissues

Question 40

Give 3 examples of secondary lymphoid tissues where B cells can mature

Answer 40

1. Spleen 2. Lymph nodes 3. GALTs

Question 41

What does HEV stand for?

Answer 41

High Endothelial Venule

Question 42

How do B cells enter into lymph nodes?

Answer 42

HEV

Question 43

T/F B cells are draw to secondary lymphoid tissues by chemokines

Answer 43

True

Question 44

What are the steps of B cell activation in the Lymphoid tissues?

Answer 44

1. Antigen Exposure in the cortex 2. Interaction with T cells 3. Migration, secondary lymphoid follicle formation, and clonal expansion 4. Plasma cell production

Question 45

What does the IgD/IgM expression look like in a Mature Naive B cell?

Answer 45

- Increased IgD expression | - Decreased IgM expression

Question 46

What are the steps of B cell maturation within secondary lymphoid tissues?

Answer 46

1. Chemokine CCL21 attracts immature B cells to HEV 2. Chemokins CCL21 and CCL19 attract B cells into Lymph Node 3. Chemokine CXCL13 attracts B cells into the primary follicle 4. Interactions with follicular dendritic cells and cytokines drives the maturation of immature B cells 5. Mature B cells recirculated between lymph, blood, and secondary lymphoid tissues

Question 47

Name two attributes of Positive Selection

Answer 47

1. Lymph Node Localization | 2. BAFF signaling