Adaptive Immunity: B cells Flashcards Preview

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Flashcards in Adaptive Immunity: B cells Deck (39):
1

Most common Ab

IgG

2

Heavy chain is recombination of ____ segments

V, D, J

3

Light chain is recombination of ____ segments

V, J

4

Has 4 constant regions per H chain

IgM, IgE

5

Found mainly in blood

IgM

6

Secreted as monomer

IgG, IgE

7

Secreted as dimer

IgA

8

Secreted as pentamer

IgM

9

IgE found most where?

Tissue bound to mast cells

10

Ab in transplacental transfer

IgG

11

Agglutination protects against ___

extracellular bacteria

12

Neutralization protects agains ____

viral infection , bacterial exotoxins and endotoxins

13

NK cells express ____ Fc receptors

IgG

14

Pro-B cell stage

VDJ recombination at heavy chain loci

15

Pre-B ell stage

VJ recombination at light chain loci

16

Surrogate light chain complex

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

17

pre-B cell complex

= surrogate light chain complex + u heavy chain protein

18

What do both B1 and B2 B cells express?

CD19, CD20, IgM, IgD

19

Levels of IgM and IgD on B1?

High IgM, low IgD

20

Levels of IgM and IgD on MZ B cells?

High IgM, low IgD

21

Levels of IgM and IgD on follicular B cells?

High IgD, low IgM

22

B1 B cells are enriched in ____

serosal lined cavities: pleural and peritoneal cavities

23

B1 B cell function:

Spontaneously differentiate into plasma cells
Secrete IgM abs w/o stimulation

24

Where are MZ B cells found?

spleen

25

When do MZ B cells respond?

During T cell-independent (TI) responses

26

Where are follicular B cells found?

Secondary lymphoid organs: Spleen, Lymph nodes, MALT

27

Most numerous B cell subset?

Follicular B cells

28

When do follicular B cells respond?

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

29

Function of follicular B cells?

Source of high affinity, switched Abs
Give rise to memory B cells and long term plasma cells

30

CXCL13

Secreted by follicular dendritic cells to direct B cells to follicles

31

CXCR5

Receptor to CXCL13 on B cells to direct them to follicles

32

CCL19, CCL21

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

33

CCR7

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

34

CD79a, CD79b

Adapter molecules that connect surface Ig to intercellular signaling pathways

35

CD19, CD21, CD81

Co-receptor molecules in signal 1 of B cell activation
Amplify CD79a/b induced signals

36

What Ab is primarily secreted during TI response?

IgM

37

CD154

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

38

CD40

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

39

Hyper IgM syndrome caused by ____

mutation of CD154 --> No TD response