Differentiation and Funciton of CD8+ T Cells (2)

Question 0

When activated B cells begin to produce Abs other than IgM and IgD, this process is called?

Answer 0

Heavy chain isotype (class) switching.

Question 1

Progeny of B cells will proliferate and differentiate into what 4 possible cells?

Answer 1

1) Plasma Cell
2) Other Ig isotypes
3) Affinity Maturation
4) Memory Cells

Question 2

What cell facilitates the formation of germinal centers?

Answer 2

Follicular helper T cell

Question 3

Describe T-dependent response.

Answer 3

Activated B cells differentiate into Ab-secreting plasma cells. Plasma cells migrate from GC’s in the periphery lymphoid organs to the bone marrow where they will live for many years and continually secrete Abs.

Question 4

Describe T-Independent response.

Answer 4

Elicited by engagement of BCR. B cells are activated by non-protein Ags and may differentiate into memory cells. Memory T cells survive in resting state w/o secreting Abs for many years, but they mount rapid responses on encouters with the Ag.

Question 5

When is isotype switching usually seen and what is the main driver of this process?

Answer 5

Typically seen in humoral immune response to protein Ags. T cell dependent signals drive isotype switching and affinity maturation. Heavy chain isotype switching and affinity maturation are increased in the secondary response to protein Ags.

Question 6

Describe primary immune response.

Answer 6

Naive B cells are stimulated by Ag, activated, and differentiate into Ab-secreting cells that produce Abs specific for the eliciting Ag. Mainly IgG and IgM are produced.

Question 7

Describe the secondary immune response.

Answer 7

Elicited when the same Ag stimulates memory B cells, leading to production of greater quantities of specific Abs than are produced in the primary response.

Question 8

The movement into lymphoid follicles is guided by what chemokine and what cells secrete this chemokine?

Answer 8

Follicular Dendritic Cells secrete CXCL13. CXCL13 attracts naive B cells into the follicles.

Question 9

Follicular B cell survival depends on two signals, name them.

Answer 9

1) BCR

2) cytokine BAFF

Question 10

B cell activation is facilitated by what coreceptor on B cells.

Answer 10

CR2/CD21

Question 11

Helper T cells are activated by recognizing Ags on B cells expressing what?

Answer 11

B cells that express CD40L. CD40L binds to CD40 on B cells and stimulates B cell proliferation and differentiation.

Question 12

Tfh are drawn into lymphoid follicles by what chemokine? What role do the Tfh cells play?

Answer 12

CXCL13. Play critical roles in germinal center formation and function.

Question 13

Tfh cells secrete what that contributes to isotype switching?

Answer 13

1) IFN-gamma

2) IL-4