Cellular Immune Response, Part III

Question 1

CD8+ cells are asssociated with killing cells that are infected. What other roles do they have?

Answer 1

• Eradication of tumors
• Cytokine production
• Acute rejection of organ allografts

Question 2

What is contained within cytotoxic T cells?

Answer 2

Modified lysosomes with perforins and granzymes

Question 3

What is cytokine is predominantly produced by T_C cells?

Answer 3

IFN gamma

Question 4

What TF’s, or transcription factors are associated with cytotoxic T cells?

Answer 4

T-bet and Oesodermin

Question 5

Tumor antigen can be presented via cross-presentation by a small subset of antigen presenting cells. What is meant by cross-presentation?

Answer 5

APC’s that are capable of expressing an antigen without becoming infected and don’t endogenously produce viratl antigens

Question 6

In weak innate immune responses, CD_+ T helper cells are required. They also may be required for CD_+ T cell responses to latent viral infections.

Answer 6

CD4+

CD8+

Question 7

Proliferation and differentiation of CD8+ T cells into effector CTL’s and Memory CTL’s, is the reaction stemming from recognition of what interleukin by CD8+ cells?

Answer 7

IL-2

Question 8

In order for Memory CD8+ T cells to survive, what interleukin is required?

Answer 8

IL-15

Question 9

What interleukin is produced by CD4+ Tcells to induce CD8+ T cell memory?

Answer 9

IL-21

Question 10

IL-12 and Type I IFN’s are associated with what response to naive CD8+ cells?

Answer 10

Stimulation and differentiation into effector CTL’s

Question 11

What are the functions of CD8+ CTL’s?

Answer 11

Secretion of IFN gamma, and eliminating intracellular microbes by killing infected cells

Question 12

What steps are involved in the process of CTL-mediated cytotoxicity?

Answer 12

• Antigen recognition
• Activation of CTL’s
• Granule exocytosis to target cell
• Release or detachment of CTL’s

Question 13

While an immunological synapse must be present, what adhesion molecules bound together?

Answer 13

ICAM-1 of the target cell to the LFA-1 of the CTL

Question 16

Describe the pathway involved with CTL eliminating target cells with their granules?

Answer 16

Granzyme B and Perforin are released into the target cell via an endosome, where they are then released into the cytosol to activate caspases leading to apoptosis

Question 17

Describe the Fas/FasL killing pathway of CTL’s.

Answer 17

The recognition of CTL’s Fas ligand on the target cells Fas receptor, which leads to apoptosis

Question 18

In chronic viral infections, CD8+ T cells are initated but fail to eliminate target cells. How does this “exhaustion” occur?

Answer 18

Due to a decreased in IFN gamma production, and increased expression of inhibitory receptors on CD8+ T cells

Question 19

Feline viral rhinotracheitis, feline calcivirus, canine distemper, and feline leukemia, are all examples of -?

Answer 19

Chronic viral infections