B cell development 1

Question 1

Where do B cells develop?

Answer 1

Bone marrow

Question 2

Where do B cells go after developing in the bone marrow?

Answer 2

Secondary lymphoid tissues

Question 3

What is tolerance?

Answer 3

Removing self reactive B and T cells

Question 4

What are secondary lymphoid tissue exmpes?

Answer 4

Lymph nodes, spleen, blood, lymph, peyers patches

Question 5

Where may B cells encounter an antigen and thus get activated?

Answer 5

Secondary lymphoid tissues

Question 6

What do pro-b cells develop from?

Answer 6

Hematopoietic stem cells

Question 7

What cells can be formed from myeloid progenitors?

Answer 7

Neutrophils, macrophages, eosinophils, RBCs,

Question 8

What cells can be formed from lymphoid progenitors?

Answer 8

T cells, B cells, NK cells

Question 9

What are CDs?

Answer 9

Surface proteins–> cluster of differentiation

Question 10

What is an indicator of a cell differentiating into a B cell?

Answer 10

CD127 (a component of the IL7 receptor)

Question 11

How is B cell development direted?

Answer 11

Integrins on the B cell interact with molecules on the surface of the bone marrow

Question 12

How is a B cell directed to become a B cell?

Answer 12

Interaction w/ bone marrow stromal cell that gives the signal for IL7 to be produced. IL7 then directs the b cell

Question 13

What configuration are heavy and light chain genes in in stem cells?

Answer 13

Germline

Question 14

What configuration are the heavy chain and light chain genes in early pro b cells?

Answer 14

Heavy chain = D-J rearrangement
Light chain = germline

Question 15

Where does D-J rearrangement occur?

Answer 15

Both chromosomes

Question 16

What configuration are the heavy chain and light chain genes in late pro b cells?

Answer 16

Heavy chain = V-DJ rearrangement
Light chain = germline

Question 17

Where does V-DJ rearrangement occur?

Answer 17

Only one chromosome

Question 18

What configuration are the heavy chain and light chain genes in large pre b cells?

Answer 18

Heavy VDJ are rearranged
light chain is germline

Question 19

When in B cell development do light chain genes rearrange?

Answer 19

Small pre-b cell

Question 20

When in B cell development is the heavy chain gene transcribed into mRNA?

Answer 20

Large pre-B cell

Question 21

Where is the heavy chain stored after it is made, and before it has associated with a light chain?

Answer 21

The endoplasmic reticulum

Question 22

What configuration are the light chain genes in in the small pre-b cell?

Answer 22

V and J are rearranging

Question 23

What is a pre-b receptor

Answer 23

An IGM heavy chain associated with surrogate light chain polypeptides

Question 24

Which cells express a pre-b receptor?

Answer 24

pre-b cells

Question 25

What does expression of a pre-b cell receptor signal the cell to do?

Answer 25

Divide and replicate

Question 26

WHen is the proliferation step in the stages of b cell development in the bone marrow?

Answer 26

Before the small pre-b cell is achieved and after the large pre-b cell

Question 27

Once the B cell has been stimulated to divide by the pre b cell, what do they do?

Answer 27

They independently rearrange their light chain genes

Question 28

When rearranging genes, what is the proportion of cells that are going to be productive?

Answer 28

just under 2/3--> 2/3 will cause a frame shift and some of the 1/3 will be stop codons then repeat f the 2nd chromosome if it doesn't work on the first

Question 29

How many light chain loci are there in a cell?

Answer 29

4--> one kappa and one lambda, then double bc one chromosome from mother and one from the father

Question 30

How many chances do you have to productively rearrange the light chain loci?

Answer 30

4

Question 31

Which light chain genes are attempted to be rearranged first?

Answer 31

Kappa

Question 32

What happens if none of the light chain rearrangements are successful?

Answer 32

Cell will die by apoptosis