5 Humoral Immunity (1 Hour)

Question 1

Where do marginal B cells reside? What do they react to?

Answer 1

Spleen

Blood-borne polysaccharide Ags

Question 2

Naive B cells travel where to get activated?

Answer 2

Spleen and lymph nodes

Question 3

How does the number of responding B cells get gated?

Answer 3

There is only so much survival signal produced in these secondary organs

Question 4

How many signals are required for complete activation of B cells?

Answer 4

2

Question 5

Where is the Ag recognized in B cells?

Answer 5

Surface Ig

Question 6

How many BCR must be involved for full activation?

Answer 6

2 or more

Question 7

What is another way to activate B cells without using the surface Ig?

Answer 7

Recognize pathogens by attached C3d (uses CR2 and CD19)

PAMP being recognize by TLR

Question 8

What signal is importation to leave the follicle? What is upregulated to get interaction with Th?

Answer 8

CCR7; CXCR5

Question 9

Memory and class switching require what cell type?

Answer 9

Th

Question 10

What is the T independent activation of B cells done by

Answer 10

TI-1 antigen

Question 11

What event causes an upregulation of CD40?

Answer 11

CD80 on B cell binding to CD28 on T cell

Question 12

What does CD40 and CD40L do?

Answer 12

Allows full activation of B cell

Question 13

What is the purpose of AID in B cells?

Answer 13

Induce changes to B cells in the lymph nodes to create diversity of receptors

Question 14

What enzyme causes somatic hypermutation? What cells do this?

Answer 14

AID, changes C to U allowing ApeI to create double strand breaks to mutate DNA in B cells

Question 15

What causes isotype switching to IgG?

Answer 15

IFNg

Question 16

What causes isotype switching to IgE

Answer 16

IL4

Question 17

What cells survive in germinal centers?

Answer 17

Those with the highest affinity to what is being presented on the follicular dendritic cell and to T helpers in the follicles

Question 18

How long do plasma cells live? What do they do?

Answer 18

Short lived (when T indep act.) or long lived (T dep. act.)

They pump tons of Ig out

Question 19

What anti-apototic protein do memory B cells express?

Answer 19

Bcl2

Question 20

What surface markers are found on memory B cells?

Answer 20

CD27 and CD45r

Question 21

What Ig causes feedback inhibition

Answer 21

IgG

Question 22

What Ig can cross placenta?

Answer 22

IgG

Question 23

What receptor do phagocytes have to induce opsonization

Answer 23

Fcgamma

Question 24

What Fc receptor causes activation of mast cells and basophils? What Ig does it bind?

Answer 24

Fc(epsilon)RI

IgE

Question 25

What 3 ways do Ab affect neutralization

Answer 25

Block microbe from entering
Block microbe from binding and entering cell
Blocks toxins from binding to cellular receptors

Question 26

What Fc receptor functions to opsonize? What Ig is involved?

Answer 26

Fc(gamma)RI

IgE

Question 27

What is Fc(gamma)RIII also called?

Answer 27

CD16

Question 28

What does CD16 bind to? Where is it found? What does it do?

Answer 28

Low-affinity Fc(gamma)RIII binds IgG weakly

NK cells

Causes NK to destroy cell

Question 29

What are autoimmune diseases treated with? How does it work?

Answer 29

IVIG

Engages FcR on B cells which tunes down the response

Question 30

Where are IgE Fc receptors found?

Answer 30

Mast cells

Causes degranulation and eosinophil activation —> helminth death

Question 31

What transports IgG to be transported across the placenta?

Answer 31

FcRn