3 Humoral Immunity I

Question 1

T-F—each mature B cell clone in the periphery expresses only one type of antibody?

Answer 1

True

Question 2

T-F—in a typical infection there are many B cells that can bind to a single antigen in the periphery?

Answer 2

False—few

Question 3

What is the difference between a B-1a cell and B-1b cell markers?

Answer 3

B1-b does not have CD5

Question 4

What is the difference between marginal zone B-2 cells and Follicular B-2 cells markers?

Answer 4

Marginal zone does not have CD23

Question 5

Are many B-1 cells produced in the adult?

Answer 5

No–few…most are generated in fetus and neonate liver and bone marrow

Question 6

Can B-1 cells self renew in the periphery?

Answer 6

yes

Question 7

Are many B-2 cells produced in the fetus?

Answer 7

No- some, FO B cells in the neonate but are produced continuously throughout life in bone marrow

Question 8

Are marginal zone B cells present at birth in the periphery?

Answer 8

No

Question 9

T-F–rearrancged heavy chains contain only a subset of Vh elements present in germ line? What does it mean?

Answer 9

True- antibodies produced by B-1 B cells tend to bind certain types of macromolecules

Question 10

Where do B-1 cells primarily localize?

Answer 10

to serous body cavities–lung pleura and peritoneal cavity

Question 11

Are B-1 cells present in large numbers in the spleen and lymph nodes?

Answer 11

No

Question 12

What cells are a main source of Natural IgM?

Answer 12

B-1 cells spontaneously produce without infection

Question 13

What are the 2 distinct B 2 subsets?

Answer 13

marginal zone and follicular

Question 14

What is the antibody repertoire biased towards recognizing in MZ cells? Where does MZ localize?

Answer 14

• microbial products

- white puple marginal zone of spleen.

Question 15

Where does FO B cells localize?

Answer 15

follicles in spleen and lymph node—it is the most abundant B cell subset

Question 16

Activated follicular B cells migrate where?

Answer 16

toward T cell zones to interact with helper T cells

Question 17

What are marginal zones exposed to?

Answer 17

Red pulp–exposed to antigens in blood stream and will secrete IgM into blood stream

Question 18

Does BCR have an intrinsic signaling ability?

Answer 18

No

Question 19

What connects antibody to intracellular signaling pathways?

Answer 19

CD79alpha

Cd79beta

Question 20

What coreceptor molecles amplify signals of Ig alpha/beta?

Answer 20

CD19, CD,1, CD81

Question 21

What is signal 1 of the B cell activation?

Answer 21

engagement of multiple BCRs

Question 22

What is signal 2 of the B cell activation?

Answer 22

Provided by an innate receptors or CD4 T cells

Question 23

What is signal 3 of the B cell activation?

Answer 23

cytokines produced by neighboring interacting cells

Question 24

Signal 1 alone causes?

Answer 24

cell deletion or anergy

Question 25

What does the need of 3 signals create?

Answer 25

dependence on activation of other cell types to safeguard against spurious antibody responses

Question 26

What does TD stand for in a TD response?

Answer 26

thymus dependent--thus require CD4 help

Question 27

Are TD responses operating in later or earlier stages of immune response?

Answer 27

Later

Question 28

Does TD response generate high affinity antibodies?

Answer 28

yes

Question 29

Does TD establish long term immunity as elicited by infection or vaccination?

Answer 29

Yes

Question 30

Are there more or less magnitude of TI responses than TD responses?

Answer 30

Less---and contribute little to long term humoral immunity

Question 31

What are TI responses induced by?

Answer 31

polymeric complexes containing repetitive structures

Question 32

What type of antibodies typically come from TI response?

Answer 32

IgM

Question 33

What is the key benefit of TI response?

Answer 33

source of antibodies in early stages of immune response

Question 34

When are TI responses not effective? Why

Answer 34

in the neonate--marginal B cell compartment is poorly developed

Question 35

What type of TI antigen--polymers displaying repeating copies of epitopes that can engage multiple B cell receptors on a single cell?

Answer 35

Type 1 antigen [signal 1]

Question 36

What type of TI antigen--contain a component that can directly activate patter recognition receptors?

Answer 36

Type 1 TI antigen [signal 2]

Question 37

What type of TI antigen- polymers displaying repeating copies of epitopes that can engage multiple B cell receptors on a single cell?

Answer 37

Type 2 TI antigen [signal 1]

Question 38

What type of TI antigen- does not inherently contain a means to provide a second signal?

Answer 38

Type 2 TI antigen

Question 39

What type of TI antigen- able to recruit innate components (complement)/

Answer 39

Type 2 TI antigen [signal 2]

Question 40

Is lipopolysaccharide a type1 or type 2 antigen? can they be whole cells, aggregates and debris?

Answer 40

type 1 TI antigen, yes [forms BCR complex and can engage TLR4, and elicits cytokine production from innate cells…all 3 signals]

Question 41

What displays LPS on surface?

Answer 41

Gram negative

Question 42

Are polysaccharides an example of a type II TI antigen?

Answer 42

Yes- provides signal 1 but not signal 2

Question 43

TI responses are mounted primarily by >? why?

Answer 43

B-1 and Marginal Zone B cells [Why? repertoire is enriched for reactivity against microbial antigens, their anatomic location facilitates, biochemically wired for rapid response]