B-cell Immunity

Question 1

PW of BC

Answer 1

1. Search for infection
2. Activate
3. Clonal selection
4. Differentiation in Ab secreting PC

Question 2

Where do BCs dev?

Answer 2

In BM,

dont leave until mature

Question 3

BC in BM

Answer 3

Many cells produced by BM everyday that start PW toward BC-most will die

Question 4

What is a naive immature BC?

Answer 4

BC that has not seen Ag

Question 5

Where do BC come from?

Answer 5

Pluripotent cell

• which undergo diff into
• common lyphoid progenitor (can become both B and T cell)
• BC-precursor
• Pro-BC

Question 6

What are the steps in BC dev?

Answer 6

Stem Cell--> non rearranged gene
Early Pro BC --> D-J of HC rearranged
Late Pro BC --> V-DJ of HC rearranged
Large pre-BC-->successive rearrangement
Small pre-BC--> V-J of LC rearrange
Immature BC-->VJ rearranged 
-IgM on surface

Question 7

What does the Pre-BCR signal?

Answer 7

Functional receptor made (similar to TC )

• there are no light chain made, but the BC needs to know the HC are functional
• SURROGATE LC composed of 2 V-preB and gamma 5 oligomerize on surface when there is a functional HC

Question 8

What components are needed for signaling of BCR?

Answer 8

Ig-alpha and Ig-beta

Question 9

What occurs onces HC made?

Answer 9

Rearrangement of LC

-Kappa, if both gene rearrangements are unsuccessful move onto lambda

Question 10

What are the checkpoints in BCR?

Answer 10

1. pre-BCR
   Make sure HC correct, if not cell will die
   2.BCR
   Make sure have functional LC, if not will die

Question 11

What defines stages in BC dev?

Answer 11

Markers

Question 12

What can occur during BC dev?

Answer 12

• Double stranded breaks induced in BC
• ->Chrom translocation can occur
• ->Chrom aberrations

Question 13

B2 vs B1?

Answer 13

B1- dont go through ALL dev stages (produced in fetus before growth)
**B2- Follicular BCs

Question 14

How do BC avoid self? (occurs after rearrangement)

Answer 14

Through central tolerance

-negative selection