Lecture 12

Question 1

When does B cell light chain rearrangement occur?

Answer 1

Light chain gene rearrangement occurs in pre B cell resulting in kappa or lambda light chain

Question 2

What does kappa or lambda chain become?

Answer 2

IgM on surface

Question 3

How do you know something is a B cell?

Answer 3

When you see IGM on cell surface you know it is a B cell

Question 4

Antigen dependent/independent portions of B cell development?

Answer 4

What happens in marrow is antigen independent

What happens out of marrow is antigen dependent

Question 5

Which B cells are innate like?

Answer 5

B1 and marginal

Question 6

Describe B 1 and marginal B cells?

Answer 6

Not truly innate as they rearrange which is adaptive
Don’t require T cell help
Do not have memory

Question 7

What is the classic B cell?

Answer 7

B2

Question 8

Where is B1 made?

Answer 8

Fetal liver

Question 9

Are B1 cells continually made?

Answer 9

No

Question 10

Where are B1s found?

Answer 10

B1 cells primarily found in peritoneal and pleural cavity

Not found in blood or normal lymphoid tissue

Question 11

Describe B1?

Answer 11

No isotype switch
Mostly against carbs
Do not use T cell help
Self renewing

Question 12

Describe marginal B cells?

Answer 12

First line of defense
Made after birth
Like B1 cells but located in marginal zone of spleen

Question 13

What happens if too little antigen is present?

Answer 13

May gain tolerance and not be able to respond later

Question 14

What affects immongenicity?

Answer 14

Size - Bigger antigen bigger response
Route -
Ajduvent

Question 15

Whey is insulin not immunogenic?

Answer 15

Too small

Question 16

How big must something be to generate immune response?

Answer 16

10k daltons

Question 17

Which routes are best for vaccination?

Answer 17

• Subcutaneous > intraperitoneal > IV or intragastric

Question 18

Soluble or nonsoluble antigen generate better response??

Answer 18

Non soluble

Question 19

Most common adjuvant?

Answer 19

Aluminum hydroxide, AKA alum

Question 20

Two signals needed for B cell activation?

Answer 20

Signal one is taking up antigen through IGM

Signal two comes from T cell

Question 21

What are T inidependent B cells?

Answer 21

T independent B cells are usually B1 cell type that recognize carbs

Question 22

What happens to activated B cells?

Answer 22

B Cells become germinal centers which secrete plasma cells and memory B cells

Question 23

B & T cell interaction?blem

Answer 23

They do not recognize the same epitope
B cells recognize native epitope
B cells recognize confirmation determinant not linear peptide
T cells recognize a peptide in context of MHC
T cells recognize linear peptide

Question 24

Which B cell response do babies have?

Answer 24

T dependant
Do not have T independant so cannot react with carbs
This is problem with hemapluous flu as it is carb

Question 25

What does tetansus toxoid do?

Answer 25

Attaches to carb portion of flu so baby immune system can recognize tetanus protein portion T cell will then react protein portion activating B cell In this way baby has tricked immune system to making T independant response even though they cannot generate one

Question 26

How are proteins and carbs handled in B cell?

Answer 26

Proteins - t dependent antigens | Carbs - T independent antigens

Question 27

How does secondary response increase affinity?

Answer 27

Somatic hypermutation

Question 28

What is required for class switching?

Answer 28

AID B cell starts out as IgM/IgD Need aid to switch

Question 29

Where does isotype switch occur?

Answer 29

Germinal center

Question 30

Two dypes of somatic rarrengment?

Answer 30

Isotype switch | VDJ rearrangement

Question 31

What is required for rearrangment?

Answer 31

Rag1/2

Question 32

What can happen in germinal center?

Answer 32

Isotype switch Rearrangement Memory cell development Plasma cell development

Question 33

What happens in dark and light zone of germinal center?

Answer 33

Dark zone - mutation occurs here | Light zone - mechanism where B cells with high affinity occur here

Question 34

What happens to low affinity or self reactive B cells?

Answer 34

If cell is low affinity or self affinity it will not be activated and will die BCR will not be cross linked so it cannot present antigen to T cell and will die

Question 35

What happens to low affinity or self reactive B cells?

Answer 35

If cell is low affinity or self affinity it will not be activated and will die BCR will not be cross linked so it cannot present antigen to T cell and will die

Question 36

What do follicular dendritic cells do?

Answer 36

Found in germinal centers & carry antigen for B cell to present to T Found in light zone and have antigen on surface B cell will respond to this and take it up if there is a match to present to T cell

Question 37

What must B cell in germinal center do for survivial?

Answer 37

For the B cell to be selected by T cell for survival, it must present something to T cell

Question 38

What are TI antigens?

Answer 38

TI antigen - T independent most likely a carbohydrate TI response have no germinal centers are there are no T cells No memory, mutation, or isotype switch They can make plasma cells but only IGM

Question 39

What are TI antigens?

Answer 39

TI antigen - T independent most likely a carbohydrate TI response have no germinal centers are there are no T cells No memory, mutation, or isotype switch They can make plasma cells but only IGM