B cell development

Question 1

Location of the 6 phases of B cell development

Answer 1

1-2: bone marrow, 3-6 secondary lymphoid tissue

Question 2

Stromal cells

Answer 2

Provide adhesion molecules for B cells and growth factors

Question 3

Importance of allelic exclusion

Answer 3

Makes immunoglobulins more effective.

Question 4

Pro-B

Answer 4

Must provide a functional heavy chain to proceed

Question 5

VpreB and γ5

Answer 5

Surrogate light chains, that gauge the functionality of the heavy chains

Question 6

Pre-BCR

Answer 6

Functional heavy chain with surrogate light chains

Question 7

Consequence of creation of pre-BCR

Answer 7

Clonal expansion, shut down of rearrangements.

Question 8

Consequence of failure to create a pre-BCR

Answer 8

Apoptosis

Question 9

Number of light chain loci

Answer 9

4: κ and γ on each chromosome - several attempts are possible

Question 10

Two checkpoints in B cell development

Answer 10

1: functional pre-BCR
2: functional BCR

Question 11

Pax-5

Answer 11

Important transcription factor for B cell development - causes chromatin changes around BCR loci.

Question 12

Enzymes needed for carrying out gene rearrangement

Answer 12

RAG-1 and RAG-2

Question 13

Elimination of self-reactive B cells

Answer 13

Binding of antigen in bone marrow causes retainment and receptor editing

Question 14

Receptor editing

Answer 14

The self-reactive B cell has a change another rearrangement of its light-chain.

Question 15

Clonal deletion

Answer 15

Continued failure to produce a non self reactive BCR causes apoptosis.

Question 16

Tolerance to soluble self antigens

Answer 16

Immature B-cells that bind antigen before reaching the lymph node causes anergy and apoptosis.