Adaptive Immunity: B cells

Question 1

Most common Ab

Answer 1

IgG

Question 2

Heavy chain is recombination of ____ segments

Answer 2

V, D, J

Question 3

Light chain is recombination of ____ segments

Answer 3

V, J

Question 4

Has 4 constant regions per H chain

Answer 4

IgM, IgE

Question 5

Found mainly in blood

Answer 5

IgM

Question 6

Secreted as monomer

Answer 6

IgG, IgE

Question 7

Secreted as dimer

Answer 7

IgA

Question 8

Secreted as pentamer

Answer 8

IgM

Question 9

IgE found most where?

Answer 9

Tissue bound to mast cells

Question 10

Ab in transplacental transfer

Answer 10

IgG

Question 11

Agglutination protects against ___

Answer 11

extracellular bacteria

Question 12

Neutralization protects agains ____

Answer 12

viral infection , bacterial exotoxins and endotoxins

Question 13

NK cells express ____ Fc receptors

Answer 13

IgG

Question 14

Pro-B cell stage

Answer 14

VDJ recombination at heavy chain loci

Question 15

Pre-B ell stage

Answer 15

VJ recombination at light chain loci

Question 16

Surrogate light chain complex

Answer 16

Made by Pre-B cells (Vpre B and lambda 5 proteins)

Question 17

pre-B cell complex

Answer 17

= surrogate light chain complex + u heavy chain protein

Question 18

What do both B1 and B2 B cells express?

Answer 18

CD19, CD20, IgM, IgD

Question 19

Levels of IgM and IgD on B1?

Answer 19

High IgM, low IgD

Question 20

Levels of IgM and IgD on MZ B cells?

Answer 20

High IgM, low IgD

Question 21

Levels of IgM and IgD on follicular B cells?

Answer 21

High IgD, low IgM

Question 22

B1 B cells are enriched in ____

Answer 22

serosal lined cavities: pleural and peritoneal cavities

Question 23

B1 B cell function:

Answer 23

Spontaneously differentiate into plasma cells

Secrete IgM abs w/o stimulation

Question 24

Where are MZ B cells found?

Answer 24

spleen

Question 25

When do MZ B cells respond?

Answer 25

During T cell-independent (TI) responses

Question 26

Where are follicular B cells found?

Answer 26

Secondary lymphoid organs: Spleen, Lymph nodes, MALT

Question 27

Most numerous B cell subset?

Answer 27

Follicular B cells

Question 28

When do follicular B cells respond?

Answer 28

During T cell-dependent (TD) responses and germinal center reaction

Question 29

Function of follicular B cells?

Answer 29

Source of high affinity, switched Abs

Give rise to memory B cells and long term plasma cells

Question 30

CXCL13

Answer 30

Secreted by follicular dendritic cells to direct B cells to follicles

Question 31

CXCR5

Answer 31

Receptor to CXCL13 on B cells to direct them to follicles

Question 32

CCL19, CCL21

Answer 32

Secreted by reticular cells to direct T cells to T cell zones

Question 33

CCR7

Answer 33

Receptor to CCL19, CCL21 on T cells to direct T cells towards T cell zones

Question 34

CD79a, CD79b

Answer 34

Adapter molecules that connect surface Ig to intercellular signaling pathways

Question 35

CD19, CD21, CD81

Answer 35

Co-receptor molecules in signal 1 of B cell activation

Amplify CD79a/b induced signals

Question 36

What Ab is primarily secreted during TI response?

Answer 36

IgM

Question 37

CD154

Answer 37

Expressed on activated CD4+ T follicular helper cell which binds to CD40 on B cell during cognate interaction in TD response

Question 38

CD40

Answer 38

Expressed on activated B cell that binds to CD154 on activated CD4+ T follicular helper cell during cognate interaction in TD response

Question 39

Hyper IgM syndrome caused by ____

Answer 39

mutation of CD154 –> No TD response