Humoral Immune Responses (Ch. 7)

Question 1

Humoral immune response is the primary response against what

Answer 1

Polysaccaride/lipid AG

Question 2

What Ig’s do Naive B cells express

Answer 2

Igm and IgD

Question 3

Define T-dependent B-Cell Response

Answer 3

B Cells use THC to perform isotype switching which leads to increased affinity for Ag, memory B Cells, and plasma cells

Question 4

Define T-Independent B Cell response

Answer 4

No THC used, IgM response with limited affinity

Question 5

What are the majority of B Cells

Answer 5

Follicular B-2 Cells (reside in follicles of LN) and respond to T-Dependent Response

Question 6

Define Marginal Zone B Cells

Answer 6

Reside in peripheral region of white pulp in spleen

Respond to blood born Ag

Typically only make IgM

Question 7

Define B-1 cells

Answer 7

Respond to non-protein Ag in mucosal tissue

Typically only make IgM

Question 8

Define primary response of B Cells

Time
Peak
Ab Type
Affinity

Answer 8

Usually after 5 days
Small peak
Usually IgM
Lower affinity, more variable

Question 9

Define secondary B Cell response

Time
Peak
Ab Type
Affinity

Answer 9

Usually before 5 days
Larger peak response
IgG present along with isotype switching
Higher affinity (affinity maturation)

Question 10

What is the role of macrophages in the subcapsular sinuses of LN

Answer 10

Capture Ag and present o follicles to display to B-Cells

Question 11

What must happen first for Ag recognition on B Cells

Answer 11

Cross recognition on two or more Ig’s

Question 12

How can Ag’s bind to multiple Ig’s

Answer 12

They have multiple epitopes

Question 13

What do B-cells recognize on microbes

Answer 13

C3d by using CR2

Question 14

What is the purpose of using CR2 to recognize C3d on microbes

Answer 14

Enhances B Cell activation

Question 15

Where are germinal centers found

Answer 15

In LN follicles

Question 16

B-cells that have proliferated in the germinal center then go where

Answer 16

To the light zone to be selected with the help of FDC’s

Question 17

What are follicular Helper T Cells

Answer 17

CD4 cells that have entered the LN Follicles to assist in affintiy maturation

Question 18

What functions does IgG perform on microbes

Answer 18

Oponosation

Question 19

What mediates the transfer of maternal IgG to the fetus

Answer 19

FCRN

Question 20

Define affinity maturation

Answer 20

Allows for greater affinity of Ag to Ab binding if infection is prolonged

Only seen in response to THC dependent protein Ag

Occurs in germinal centers

Caused by point mutation in the V region especially at the Ag binding hypervariable region which involves the switching of Uracil to thymidines

Question 21

What is the role of FDC within the germinal centers

Answer 21

Used to present Ag to different varieties of B-2 cells which are tested for the highest affinity. Those with lowest affinity are apoptosed

Question 22

Where are FDC’s present

Answer 22

In the light zone

Question 23

Memory B-Cells do not excrete what

Answer 23

Ab

Question 24

Mutations in affinity maturation are usually clustered where

Answer 24

In the Ag-binding regions

Question 25

Which Ig has more mutations

Answer 25

IgG

Question 26

How do THC and B Cells recognize eachother

Answer 26

With CD 40 (on BC) and CD 40L (on THC)

Question 27

FDCs are located where

Answer 27

In the light zone

Question 28

What doe FTH cells recognize on B cells that induce apoptosis if not chosen for survival

Answer 28

Fas

FTH express FasL

Question 29

Memory cells are generated mainly in the GC for what

Answer 29

T-depdented protein Ag

Question 30

Memory B-cells express high levels of what

Answer 30

Bcl-2 (anti-apoptosis protein)

Question 31

MZ B Cells mainly respond to what

Answer 31

Polysaccharides

Question 32

For vaccines to work, what do they have to induce

Answer 32

Affinity maturation and memory B cell formation

Question 33

Memory from Vaccines only works if what happens

Answer 33

The vaccine can activate THC

Question 34

Equation for mutated Ig V genes

Answer 34

Vh + Vl = 700