B cell Immunity

Question 1

what are B cells called when they exit bone marrow

Answer 1

mature naive B cells

Question 2

first 4 stages of B cell development

Answer 2

-pluripotent hematopoietic stem cell
-common lymphoid progenitor
-B cell precursor
-pro-B cell
(then pre-B –> immature B cell –> mature naive)

Question 3

first stage of B cell with Ig status

Answer 3

large pre-B has mu chain (IgM)

Question 4

alleleic exclusion in B cells

Answer 4

allows for high avidity, monospecificity

Question 5

rescues a self-reactive B cell

Answer 5

receptor editing

Question 6

1st B cell checkpoint

Answer 6

• pre-B cell receptor

- selects for functional heavy chains

Question 7

2nd B cell checkpoint

Answer 7

B cell receptor

-selects for functional light chains

Question 8

if an immature B cell does not react with self antigen in bone marrow what happens and what is this called

Answer 8

moves to blood, expresses IgM and IgD

CENTRAL TOLERANCE

Question 9

where does B cell receptor editing occur

Answer 9

bone marrow

Question 10

peripheral tolerance

Answer 10

once B cell is already in blood stream, if IgM binds self antigen, IgD is added but then B cell becomes anergic

Question 11

describe B cell receptor

Answer 11

2 heavy chains, 2 lights chains

-also have Ig-beta and Ig-alpha

Question 12

describe B cell co-receptor

Answer 12

• components: CD81, CD19, CR2

- CR2 binds C3d on pathogen

Question 13

how do B cells see antigens

Answer 13

CR2 (part of BCR) displays antigens on macrophages

Question 14

what happens once B cell binds antigen

Answer 14

CD40 on B cell binds CD40R on helpfer Tfh (Th2) cell, B cell proliferates, differentiates

Question 15

T cell cytokines

Answer 15

drive B cell differentiation

Question 16

what happens in germinal centers of lymph nodes

Answer 16

somatic hypermutation

-intense competition for a limiting antigen