Deck 11: B-Cell Activation, Differentiation, and Memory

Question 1

With regard to the type of B-cell response generated, protein antigens typically provoke which of the following responses?

A)TI-1
B)TI-2
C)TD
D)All of the answers are correct.
E)None of the answers are correct.

Answer 1

C

Question 2

After encountering antigen, B cells express all of the following EXCEPT

A)CCR7.
B)CCL19.
C)CXCR5.
D)EBI2.
E)All of the options are expressed.

Answer 2

B

Question 3

The B-cell coreceptor CD21 associates with which host molecule?

A)C3d
B)CD19
C)The BCR
D)Fc receptors
E)None of the answers are correct.

Answer 3

A

Question 4

Activated T_H cells signal to B cells to initiate their activation program via which of the following?

A)CD40L on the T cell to CD40 on the B cell
B)CD40 on the T cell to CD40L on the B cell
C)FasL on the T cell to Fas on the B cell
D)Fas on the T cell to FasL on the B cell
E)Notch ligand on the B cell to Notch1 on the T cell

Question 5

B cells follow which of the following chemotactic signals to migrate to the cortical regions of secondary lymphoid tissue?

A)CCL19
B)CXCL13
C)CCL21
D)All of the answers are correct.
E)None of the answers are correct.

Question 6

Which of the following constitutes the critical survival cytokine for B cells in the secondary lymphoid tissue cortex?

A)BAFF
B)IL-7
C)IL-2
D)IL-6
E)None of the answers are correct.

Question 7

The first immunoglobulin isotype produced during the course of a primary immune response contains which of the following heavy chains?

A) ?
B) ?
C) ?
D) ?
E)None of the answers are correct.

Question 8

Which of the following do you expect would be actively functioning in a B cell that had migrated to a germinal center?

A)RAG1
B)Artemis
C)AID
D)Ku70
E)None of the answers are correct.

Question 9

AID converts cytosine into which of the following bases?

A)Adenine
B)Thymine
C)Deoxyuridine
D)Guanine
E)None of the answers are correct.

Question 10

Which of the following mechanisms of mutagenesis via AID activity is possible?

A)The lesion is not repaired prior to replication, resulting in a CG TA transition
B)Base excision repair, followed by error-prone DNA polymerase fill-in of the gap created.
C)Mismatch repair, followed by error-prone DNA polymerase fill-in of the gap created.
D)All of the options are possible.
E)None of the options are possible.

Question 11

SHM and CSR are both dependent on the activity of which of the following enzymes?

A)AID
B)RAG-1/2
C)DNA uridine glycosylase
D)Both AID and RAG-1/2 are required for SHM and CSR.
E)Both AID and DNA uridine glycosylase are required for SHM and CSR.

Question 12

A knockout of which of the following genes results in the inability to form germinal centers?

A)Blimp-1
B)IRF-4
C)Pax-5
D)Bcl-6
E)NF- ? B

Question 13

Which of the following is considered to be the "master regulator" of terminal plasma cell differentiation?

A)Blimp-1
B)IRF-4
C)Pax-5
D)Bcl-6
E)NF- ? B

Question 14

Blimp-1 represses the expression of which of the following transcription factors?

A)Blimp-1
B)IRF-4
C)Pax-5
D)Bcl-6
E)NF- ? B

Question 15

Which of the following factors is thought to induce expression of Blimp-1?

A)IRF-4
B)Pax-5
C)Bcl-6
D)NF- ? B
E)None of the answers are correct.

Question 16

Which of the following is a way in which follicular B cells can acquire antigen entering a lymph node via an afferent lymphatic?

A)Direct capture of whole antigen that directly enters the follicle by passing between subcapsular sinus macrophages.
B)Transfer of complement-bound antigen from surface receptors on subcapsular sinus macrophages to B cells.
C)Passage of antigen from subcapsular sinus macrophages to follicular dendritic cells to B cells.
D)Passage of antigen from DCs that reside near HEVs to B cells.
E)All of the answers are possible.

Question 17

Which of the following does NOT occur shortly following oligomerization of the BCR upon antigen binding?

A)Movement of the BCR complex into areas of the membrane called "lipid rafts".
B)Positioning of Ig. ? and g ? to allow for phosphorylation of their ITAM motifs
C)Positioning of CD3 to allow for phosphorylation of its ITAM motifs.
D)Formation of clathrin-coated pits around BCR complex.
E)All of the answers occur.

Question 18

After endocytosing its BCR cognate antigen, B cells

A)upregulate CD80
B)upregulate CD86
C)upregulate CD40
D)All of the answers are correct.
E)None of the answers are correct.

Question 19

Which of the following is or appears to be controlled by Blimp-1 during plasma cell differentiation?

A)Exit from the cell cycle.
B)Transitioning from membrane-bound to secreted IgM.
C)Loss of MHC class II from the cell surface.
D)All of the answers are correct.
E)None of the answers are correct.

Question 20

Which factors on the surfaces of B cells and T cells, through their interaction, are required to allow germinal center formation to occur?

A)CD40 and CD40L.
B)Fas and FasL.
C)CD28 and CD80/86.
D)TCR and MHC class II.
E)None of the answers are correct.

Question 21

The follicular mantle zone consists primarily of which of the following?

A)Follicular dendritic cells.
B)Naïve IgD⁺ B cells that are not participating in the response against the antigen.
C)T_FH cells.
D)Plasmacytoid dendritic cells.
E)None of the answers are correct.

Question 22

Which cells that are found within GC light zones are generally NOT found in the GC dark zones?

A)Differentiating B cells.
B)T_FH cells.
C)FDCs.
D)Naïve IgD⁺ B cells that are not participating in the response to the antigen.
E)None of the answers is correct.

Question 23

The function of SHM is BEST described by which of the following statements?

A)Increasing junctional diversity in IgH and IgL V regions.
B)Increasing the affinity of immunoglobulins for their antigen.
C)Irreversibly changing the isotype of immunoglobulin.
D)Promoting alternative splicing of an immunoglobulin heavy chain transcript to produce different isotypes on the B-cell surface.
E)None of the answers are correct.

Question 24

To which compartment in the body can long-lived plasma cells potentially be retained for the lifetime of the individual?

A)Medullary cords of the lymph node.
B)Germinal center.
C)Bone marrow.
D)Red pulp of spleen.
E)None of the answers are correct.

Question 25

Post-germinal-center plasma cells that take up residence in the bone marrow can be found in close proximity to which other type of immune cells that provide survival factors to the plasma cells?

A)Macrophages
B)DCs
C)Monocytes
D)Eosinophils
E)All of the answers are correct.

Question 26

Which immunoglobulin isotype CANNOT be produced by memory B cells?

A)IgM
B)IgG1
C)IgA2
D)IgE
E)All of the answers can be produced by memory B cells.

Question 27

Which of the following antigen types could be characterized as TI antigens?

A)Soluble proteins
B)Bacterial cell wall components
C)Capsular polysaccharides
D)Both bacterial cell wall components and soluble proteins
E)Both bacterial cell wall components and capsular polysaccharides

Question 28

Which of the following is NOT true of T-independent antigens?

A)They are rarely proteins.
B)They may contain PAMPs.
C)They may be heavily polymerized.
D)They are rarely carbohydrates.
E)All of the answers are true.

Question 29

Which of the following statements are TRUE about ?? T cells and B-1 B cells?

A)Both can self-renew in the periphery and do not need to be replenished from primary lymphoid tissues.
B)Both have identical lymphocyte receptors to one another.
C)Both respond to their antigens via high-affinity receptor responses.
D)All of the answers are true.
E)None of the answers are true.

Question 30

Which of the following statements is TRUE about B-1 B cells and MZB cells?

A)Both are self-renewing in the periphery, not requiring replacement from bone marrow.
B)Both can respond to TI antigen.
C)Both do not undergo SHM.
D)Both are self-renewing in the periphery, not requiring replacement from bone marrow, and can respond to TI antigen.
E)None of the answers are true.

Question 31

What do SHP-1 and IL-10 have in common with regard to B-cell function?

A)Both exert negative regulation of B-cell activity.
B)Both exert positive regulation of B-cell activity.
C)Both are B-cell survival factors.
D)Both induce B-cell proliferation.
E)None of the answers are correct.

Question 32

Which of the following is a negative regulator of B cells?

A)CD21
B)CD22
C)CD80
D)CD86
E)All of the answers are positive regulators.

Question 33

What molecular events occur when a B cell encounters its cognate antigen for the first time? Describe the events occurring both inside and outside the cell membrane.

Question 34

How are Bcl-6 and BLIMP-1 related to B-cell fates? Which protein leads to which type of cell?

Question 35

What special role do follicular dendritic cells play in germinal centers, and how are they adapted for this role?

Question 36

What cells in our body typically have the HIGHEST rate of mutation? What is occurring in these cells? Explain.

Question 37

What is AID, what does it do, and what two B cell processes cannot happen without it?

Question 38

Why is it advantageous for most plasma cells to die by apoptosis at the end of an infection?

Question 39

What is the MOST common type of activated B cell? What are three other types and what kind of antigens do they typically recognize?

Question 40

What type of macromolecule is BEST able to produce a T-independent B-cell response? What are some common characteristics of TI antigens?

Question 41

What are three different ways memory B cells can be regulated? Why is regulation of B-cell responses important?