Quiz 5 - German - B Cells - Antibodies

Question 1

B cells produce what?

Answer 1

Antibodies

Question 2

T/F - B cells target one antigen epitope.

Answer 2

TRUE

Question 3

Plasma cells are what and secrete what?

Answer 3

Fully differentiated form of B cell

Secretes antibodies

Question 4

Small lymphocyte produces what?

Answer 4

Production of antibodies (B cells) or cytotoxic and helper fxs (T cells)

Question 5

T/F - B cells produce an antibody targeted against a single, unique antigen.

Answer 5

TRUE

Question 6

Tell me more about B cells.

Answer 6

Affect extracellular pathogens

Infinite target diversity

Low probability of reaching maturation

Undergo colonial selection and expansion

Improve targeting following activation

Persist for years

Question 7

There are 6 phases to B cell maturation. What are the first 3 phases that occur in the bone marrow?

Answer 7

I - Repertoire assembly - Generation of diverse and clonally expressed B-cell receptors in the bone marrow

II - Negative selection - Alteration, elimination, or inactivation of B cell receptors that bind to components of the human body

III - Positive selection - Promotion of a fraction of immature B cells to become mature B cells in the secondary lymphoid tissues

Question 8

What are the 3 phases of B cell maturation that occurs in the periphery?

Answer 8

IV - Search for Infection - Recirculation of mature B cells b/t lymph, blood, and secondary lymphoid tissues

V - Finding Infection - Activation and local expansion of B cells by pathogen-derived antigens in secondary lymphoid tissues

VI - Attacking infection - Differentiation to antibody-secreting plasma cells and memory B cells in secondary lymphoid tissue

Question 9

T/F - Antibodies are targeted effector proteins that target a single epitope.

Answer 9

TRUE

Question 10

T/F - Antibodies are also called immunoglobulins.

Answer 10

TRUE

Question 11

What is an epitope?

Answer 11

An exposed, small region of an antibody

Question 12

T/F - An antigen can have multiple epitopes.

Answer 12

TRUE

Question 13

What is neutralization?

Answer 13

Antibodies binding a toxin and neutralizing the threat

Question 14

T/F - Antibodies are basically targeted effector proteins.

Answer 14

TRUE

Question 15

What are the antibody classes?

Answer 15

M - Mew

A - Alpha

D - Delta

G - Gamma

E - Epsilon

Question 16

What determines antibody class?

Answer 16

ISOTYPE

Question 17

The ______ chain has a proportionally small variable region, while the ________ chain has a proportionally large variable region.

Answer 17

Heavy

Light

*Both bind antigen

Question 18

What are the 2 isotopes of the light chain?

Answer 18

Kappa

Lambda

Question 19

Which antibodies are multimeric?

Answer 19

IgM

IgA

Question 20

IgM function?

Answer 20

Neutralization

Activate complement

Transport across epithelium

Question 21

IgD function?

Answer 21

Sensitization of basophils

Question 22

IgE function?

Answer 22

Sensitization of mast cells

Sensitization of basophils

Question 23

IgG functions?

Answer 23

Neutralization

Opsonization

Sensitization for killing by NK cells

Sensitization of mast cells

Activation of complement

*T-port across placenta

Extravascular diffusion

Question 24

IgA functions?

Answer 24

Neutralization

Opsonization

Activation of complement

**T-port across epithelium

Extravascular diffusion

Question 25

What portion of antibody binds antigen?

Answer 25

Technically, both, but the FAB is what binds the antigen on the light chain

Question 26

What is an antigen?

Answer 26

Molecule recognized by a B or T cell

Question 27

What is an epitope?

Answer 27

Region of an antigen bound by an antibody or MHC/TCR

Question 28

T/F - Antibody structure facilitates fx.

Answer 28

TRUE

Question 29

Tell me the B cell development timeline and include heavy, then light chain designation.

Answer 29

Bone Marrow ``` Stem cell - germline, germline Early pro-B - germline, germline Late pro-B - DJ, germline Large pre-B - VDJ, germline Small pre-B - VDJ, germline Immature B cell - VDJ, VJ ``` Lymphoid organs/circulation ``` Immature B cell (IgM, no IgD) Immature B cell (High IgM, low IgD) Mature, naive B cell (Low IgM, High IgD) Antigen activated B lymphoblast Antibody-secreting plasma cell Memory cell ```

Question 30

T/F - Antibody genes are assembled from fragmented segments. What does this mean?

Answer 30

TRUE *Gives enormous diversity of antigen binding*

Question 31

_________ recombination creates antibody coding sequence. This is tied to specific B cell developmental stages.

Answer 31

Somatic

Question 32

What does the RAG complex do?

Answer 32

Randomly pairs gene segments

Question 33

RAG 1 and 2 complexes bind what?

Answer 33

RSSs Recombination signal sequences *Gene segments are randomly paired to create coding sequences*

Question 34

What are the three orders associated with RAG?

Answer 34

V-D-J —> V-DJ (All heavy) V-DJ —> VDJ (All heavy) V-J —> VJ (All light)

Question 35

What is junctional diversity created?

Answer 35

RECOMBINATION

Question 36

What can mutations during recombination do?

Answer 36

Throw off the sequence and antibody won’t be created properly *Frameshift/stop codon could lead to improper production of antibody*

Question 37

What is TdT?

Answer 37

Terminal deoxynucleotidyl transferase

Question 38

What are the only two antibody types that are produced simultaneously?

Answer 38

IgM IgD

Question 39

How can a single B cell express all antibody isotopes?

Answer 39

Class switching The Fc region is conserved, by the light chains can be switched Class switching is permanent IgM and IgD are the first ones expressed

Question 40

What do Fc receptors bind?

Answer 40

Conserved regions

Question 41

Tell me the three things that happen when activation occurs.

Answer 41

Activation changes B cell immunoglobulin fate 1 - Antibody secretion 2 - Somatic hypermutation 3 - Class switching —IgM/IgD —> IgG/IgA/IgE

Question 42

What does somatic hypermutation do?

Answer 42

Rapidly increases antibody affinity

Question 43

What are three main sources of antibody diversity?

Answer 43

Genetic recombination - Random Junctional diversity - Random nucleotides put in b/t the two Somatic hypermutation - Isotype switching

Question 44

Somatic hypermutation targets what?

Answer 44

The rearranged gene segments encoding the variable region

Question 45

What does polyclonal mean?

Answer 45

Multiple antibodies targeted against the same antigen

Question 46

What does monoclonal mean?

Answer 46

Single antibody target against a single antigen

Question 47

What are the 4 types of therapeutic monoclonal antibody?

Answer 47

Mouse Chimeric Humanized Human

Question 48

Antibodies are important ________ and __________ tools.

Answer 48

Diagnostic Therapeutic

Question 49

Tell me how antibodies are diagnostic.

Answer 49

Pathogen ID Protein quantification Cellular ID

Question 50

Tell me how antibodies are therapeutic.

Answer 50

Targeted killing Chemical delivery Immunomodulatory