B Cell Development

Question 1

what happens in primary lymphoid organs?

Answer 1

initial lymphocyte development occurs (also V(D)J recombination)

Question 2

what happens in secondary lymphoid organs?

Answer 2

antigens are trapped and brought into contact with lymphocytes to induce an immune response

Question 3

what are the secondary lymphoid organs?

Answer 3

spleen, lymph nodes, mucosa-associated lymphoid tissues (MALT) (Peyer’s patches, tonsils, appendix)

Question 4

from what do B cells develop?

Answer 4

pluripotent stem cells in the red bone marrow

Question 5

in what species is the gut the major site of B cell development?

Answer 5

rabbit, cattle, sheep, swine

Question 6

are the early differentiated stages of B cell development antigen independent or antigen dependent?

Answer 6

antigen independent

Question 7

what do hematopoietic stem cells lead to?

Answer 7

B lymphocytes, first distinguishable is pro-B cell

Question 8

what cell comes after pro-B cells?

Answer 8

pre-B cells

Question 9

what does the pre-B cell make?

Answer 9

mu heavy chains but no light chains
mu heavy chain paired with a surrogate light chain

Question 10

what do immature B cells express?

Answer 10

IgM with two full heavy chains and two full light chains

Question 11

what happens after an antigen is recognized by the membrane IgM of an immature B cell?

Answer 11

apoptosis (clonal deletion) or inactivation (anergy)

Question 12

what do mature B cells express at their surface?

Answer 12

IgM and IgD

Question 13

what does the interaction of a mature B cell with an antigen lead to?

Answer 13

activation

Question 14

what happens if an activated B cell receives appropriate signals (cytokines) from T cells?

Answer 14

class (isotype) switching for some of them

Question 15

does the light chain change after an activated B cell receives cytokines from T cells?

Answer 15

no, except for somatic hypermutation (somatic point mutations)

Question 16

have memory B cells undergone class switching?

Answer 16

yes

Question 17

do memory B cells secrete Ig?

Answer 17

no

Question 18

what is membrane Ig expressed at the surface with?

Answer 18

transmembrane molecule Ig alpha and Ig beta

Question 19

what are Ig alpha and Ig beta?

Answer 19

signal transduction molecules

Question 20

what is the B cell receptor?

Answer 20

Ig along with the Ig alpha and Ig beta heterodimer

Question 21

what composes the surrogate light chains?

Answer 21

lambda 5 and VpreB

Question 22

what is the receptor on the pre-B cell?

Answer 22

pre-B receptor

Question 23

what are the clinical and experimental applications of antibodies?

Answer 23

diagnostic
therapeutic
vaccination
basic research

Question 24

why are antibodies prepared from serum called polyclonal antibodies?

Answer 24

antisera contain a heterogeneous collection of antibodies derived from different B cell clones

Question 25

how are hybridomas formed?

Answer 25

fusing immortal (cancer) cells with B cells producing antibodies

Question 26

what are chimeric antibodies?

Answer 26

antibodies with mouse variable regions that have been engineered to have human constant regions

Question 27

what is enzyme linked immunosorbent assay (ELISA)?

Answer 27

an antigen antibody reaction

Question 28

is is possible to produce human monoclonal antibodies from mice?

Answer 28

yes, they have human heavy and light chain Ig loci inserted into their genomes

Question 29

what is titration ELISA used for?

Answer 29

to determine the magnitude of the antibody response in body fluids against specific antigens

Question 30

what are the ELISA types?

Answer 30

direct indirect competitive (not that common) sandwich

Question 31

what is coating in direct ELISA?

Answer 31

the immobilization of antigen, antibodies, or any other compound directly on the well surface, for the purpose of a binding assay

Question 32

what is indirect ELISA often used to determine?

Answer 32

antibody titers against antigens

Question 33

true/false: in the absence of T helper cell help, B cells only make IgM?

Answer 33

true

Question 34

true/false: in the absence of T helper cell help, B cells will make a strong secondary IgG response

Answer 34

false: need helper T cells to induce class switching to make memory B cells to get the strong secondary response

Question 35

true/false: in the absence of T helper cell help, germinal centers will not form

Answer 35

true: only primary follicles

Question 36

what is immunofluorescence assay (IFA)?

Answer 36

powerful technique that utilizes antibodies labeled with fluorescent dyes to detect specific target antigens

Question 37

what are the most common immunofluorescence assays (IFA)?

Answer 37

direct and indirect

Question 38

true/false: follicular dendritic cells have antigens bound to their surface which plays a role in affinity maturation of antibody molecules

Answer 38

true

Question 39

true/false: cytokines released by Th cells are required for class switching recombination

Answer 39

true

Question 40

how does flow cytometry work?

Answer 40

antibodies labeled with fluorochromes and the labeled cells are detected using a flow cytometer