lecture 20- B cell development

Question 1

sequential progression for B cell development (3)

Answer 1

E2A
EBF
PAX5

Question 2

commitment to the B-lymphoid lineage depends on the transcription factor _______

Answer 2

PAX5

Question 3

deletion of PAX5 in pro-B cells results in what

Answer 3

a loss of identity

Question 4

master transcription factor for B cells

Answer 4

PAX5

Question 5

Pre- BCR is what (structure)

Answer 5

heavy chain + surrogate light chain

Question 6

what is the surrogate light chain made of (2)

Answer 6

VpreB and lambda5

Question 7

what shuts down heavy chain recombination and promotes proliferation of B cells (2)

Answer 7

SLC (surrogate light chain) and IL-7

Question 8

what turns off the pre- BCR (2)

Answer 8

BTK
SLP65

Question 9

what if an immature B cell is auto reactive ?

Answer 9

it has 4 tries to recombine its light chain, 2 kappas and 2 lambdas

otherwise it gets negatively selected and undergoes apoptosis

Question 10

if a B cell survives negative selection what happens and what does it become

Answer 10

it migrates to the spleen as a transitional B cell

Question 11

what can B cells become in the spleen

Answer 11

marginal zone B cell
follicular B cell

Question 12

what kind of antigens send strong selection signals and why

Answer 12

membrane antigens because they have a very high local density

Question 13

stronger BCR signal for B cells makes it what? what about a lesser signal

Answer 13

Stronger - follicular B cell
less - marginal zone B cell

Question 14

whats essential for B cell survival

Answer 14

BAFF

Question 15

immature B cels express what antibodies

Answer 15

IgM and IgD

Question 16

is IgM and IgD a stronger signaller

Answer 16

IgM

Question 17

where is the survival checkpoint for transitional B cels

Answer 17

follicle

Question 18

traditional B cells excluded from the follicle ________________________

Answer 18

die in 2-3 days

Question 19

do marginal B cells or follicular B cells have more expression of IgD

Answer 19

follicular

marginal zone B cells express much more IgM

Question 20

are FO B cells or MZ B cells more autoreactive

Answer 20

Marginal Zone

Question 21

what are co-expressed in B cells (2)

Answer 21

Zfp318
IgD

Question 22

deletion of Zfp318 leads to a ______ of IgD

Answer 22

loss

Question 23

what does Zfp318 do

Answer 23

blocks transcriptional termination of IgM to allow for IgD splicing

Question 24

negative selection stages for B cells

Answer 24

1. bone marrow (strong signals induce light chain recombination
2. spleen (as transitional B cells now - strong signal can still promote death)

Question 25

if Zfp318 was deleted, would IgM be lost?

Answer 25

no