B-Cells

Question 1

Ability of a single B cell to express IgM and IgD molecules on its surface at the same time is possible because of?

Answer 1

Alternate RNA splicing

Question 2

What are the best marker to identify B-cells

Answer 2

CD19, CD20, CD21

Question 3

What forms the coreceptor complex during B-cell activation signal transduction

Answer 3

CD19, CD21

Question 4

What does CD20 do?

Answer 4

Not totally understood but forms a Ca+ ion channel

Question 5

These recognize different tissues and helps the migration of B-cells

Answer 5

Selectins

Question 6

The ability to change from IgM to IgE is possible by?

Answer 6

Isotype switching

Question 7

Isotype switching is rearranging of V(D)J genes within a B-cell by what process

Answer 7

DNA excision

Question 8

How is it possible for a baby to already possess B-cells with immunoglobulins before exposure?

Answer 8

Antigen-Independent Immunoglobulin Gene Rearrangement

Question 9

What is it called when a B-cell or plasma cell express a single maternal or paternal allele of a chromosome pair on a heavy and light chain?

Answer 9

Allelic exclusion

Question 10

What is it called when TdT adds or removes nucleotides when ends of the V(D)J are exposed during DNA rearrangement. Occurs in addition to the fusion of the V(D)J segments

Answer 10

Junctional diversity

Question 11

What will happen when small point mutations accumulate on DNA coding of memory B-cells light and heavy chains?

Answer 11

It will generate antibodies with increased binding affinity for its epitope

Question 12

A plasma cell making IgA antibody will not have?

Answer 12

MRNA specific for mu chain because they will be deleted

Question 13

T/F
IgM and IgD expressed on a single B-cell will have the same heavy and light chain V(D)J gene unit therefore will have the same antigenic specificity?

Answer 13

True

Question 14

What is the only method to change an antibody binding site after antigen stimulation?

Answer 14

Somatic hypermutation

Question 15

Allows mature B-cell to attach to either a delta or mu constant domains on a single idiotype generated by DNA rearrangement?

Answer 15

Alternate RNA splicing

Question 16

What are the first two immunoglobulin heavy chains classes to be expressed on the surface of a new B-cell?

Answer 16

IgM followed by IgD

Question 17

A B-cell is able to make membrane-attached or secreted versions of BCR using what method?

Answer 17

Differential Splicing

Question 18

The cytoplasmic region of surface IgM consists of how many Amino Acids

Answer 18

3 Amino Acids

Question 19

What mediates signal transduction after antigen binding to BCR on the surface of B cells?

Answer 19

Ig-alpha and Ig-beta

Question 20

Constitutive expression of MCH class II molecules is confined to what cells?

Answer 20

APC’s (B-cells, dendritic cells, and macrophages)

Question 21

There is only a small chance that corresponding MHC locus on both the homologous chromosomes of an individual will have the same allele. Expression of MHC genes is characterized by?

Answer 21

Codominant expression

Question 22

T/F
B cells express surface immunoglobulin of a specificity created by that cell’s particular immunoglobulin gene recombination

Answer 22

True