B cell activation

Question 1

what kind of B cells are T cell dependent

Answer 1

follicular B cells

Question 2

what kind of antigen do T cell dependent B cells recognize

Answer 2

proteins

Question 3

T cell dependent antibodies have high of low affinity antibodies

Answer 3

high

Question 4

T cell independent B cells

Answer 4

B-1
marginal zone B cells

Question 5

what kind of antigens for T cell independent

Answer 5

polymeric (carbohydrates)

Question 6

what other signals do T cell independent B cells use (2)

Answer 6

complement signals
PRRs

Question 7

T cell independent antibodies are mostly what

Answer 7

IgM

Question 8

immune complex to get antigens to B cell follicles

Answer 8

Antigen / antibody complex + CR1 (complement receptor 1)

Question 9

are follicular dendritic cells considered immune cells

Answer 9

no

Question 10

what displays the antigen for B cell activation

Answer 10

Follicular B cells

Question 11

can follicular dendritic cells activate T cells

Answer 11

nope

Question 12

what do FDCs express? what does it bind

Answer 12

expresses CR1 which binds C3b

Question 13

why do FDCs expresses CR1

Answer 13

when pathogens are opsonized by complement, they have C3b on them. FDC binds the C3b and presents it to B cells

Question 14

do B cells upregulate or down regulate FLIP when they recognize an antigen

Answer 14

upregulate

Question 15

whats FLIPs main goal

Answer 15

black caspase 8 activation

Question 16

what does caspase 8 do

Answer 16

induces apoptosis in cells

Question 17

what happens if B cells lack flip

Answer 17

caspase 8 would just continuously kill cells

Question 18

what cells are FLIP in

Answer 18

T cells
B cells

Question 19

what would happen if T cells and B cells overexpress FLIP

Answer 19

there would be no apoptosis ever and auto reactivity would occur

Question 20

FLIP _____________ T cell and B cell activity

Answer 20

promotes

Question 21

can one multivalent antigen activate multiple BCR’s

Answer 21

yes

Question 22

what does TCR always require to recognize the antigen

Answer 22

needs to be bound to MHC

Question 23

whats similar to CD3 in B cells

Answer 23

Iga/Igb

Question 24

whats similar to ZAP70 in B cells

Answer 24

SYK

Question 25

what does SYK and ZAP70 do

Answer 25

binds the ITAMS and activates downstream adaptors (signal amplifiers)

Question 26

shared transcription factors between TCRs and BCRs

Answer 26

NFAT NF-kb AP-1

Question 27

co receptor complex

Answer 27

complement (C3d) binds the bacteria BCR binds the antigen and co receptor CR2 binds Cd3

Question 28

2 responsibilities of BTK in B cells

Answer 28

1. early maturation. with BCR light chain recombination 2. function of the mature B cells and activating a signal

Question 29

B cell co receptors complex (3)

Answer 29

CR2 CD19 CD81

Question 30

can LPS provide signal 1 and 2 to some B cells

Answer 30

yes

Question 31

whats the bridging between TCR and BCR? whats something they both recognize

Answer 31

Lipopolysaccharides

Question 32

what TLR is involved with lipopolysaccharides

Answer 32

TLR4

Question 33

what transcription factor is activated by lipopolysaccharides

Answer 33

NF-kB

Question 34

what recognizes the LPS

Answer 34

VH

Question 35

CR2 binds

Answer 35

C3d

Question 36

5 steps to T cell dependent reaction

Answer 36

1. activation 2. migration 3. continued activation and co-stimulation 4. proliferation 5. differentiation

Question 37

CR1 binds

Answer 37

C3b

Question 38

how do CD4 T cell migrate to the B cell follicle

Answer 38

they upregulate CXCR5 receptor which is drawn to CXCL13 in the B cell follicle

Question 39

how do B cells migrate towards T cells (out of the follicle)

Answer 39

they upregulate CCR7 receptor which are drawn to CCL21/19

Question 40

T cells CD40L helps what

Answer 40

CD40 on B cells to activate and proliferate them

Question 41

2 humoural (antibody) B cell pathways

Answer 41

T cell dependant T cell independent

Question 42

FDCs use what to retain antigen (2)

Answer 42

Fc receptors complement receptors (CR1)

Question 43

T cell independent activation of B cells

Answer 43

1. BCR plus co receptor complex 2. BCR plus TLR

Question 44

TLRs that BCR can use

Answer 44

TLR4 endosomal (TLR 7/9)

Question 45

T cell dependent activation of B cells

Answer 45

B cells upregulate CCR7 receptor T cells upregulate CXCR5 and they handshake

Question 46

3 "handshakes" done by T cells and B cells in T cell dependent activation of B cells

Answer 46

1. peptide/MHC II to TCR 2. CD80/86 to CD28 3. CD40L to CD40