Lecture 11 - Differentiation and Functions of CD8 T Cells Flashcards Preview

Immunology Exam 3 - SS > Lecture 11 - Differentiation and Functions of CD8 T Cells > Flashcards

Flashcards in Lecture 11 - Differentiation and Functions of CD8 T Cells Deck (18)
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0
Q

What activates naive T cells?

A

Dendritic cells

note; activation may include coordinated signaling (interaction of DC and T cell surface or secreting cytokines)

1
Q

What is the life cycle of T lymphocytes?

A
  1. Generated in bone marrow
  2. migrate to thymus
  3. generation of a receptor for Ag
  4. leave in naive state to populate LN
  5. become activated in LN by Ags presented to them by APCs
  6. activated then functional polarization
2
Q

What is functional polarization?

A

T cells take on a particular set of tasks that promote the adaptive immune response

3
Q

CD8 T cells recognize which MHC class?

A

Class I MHC associated peptides

4
Q

How are CD8 T cells activated?

A

by cross presentation mechanism of Ags

5
Q

How does CD4 help in the activation of CTLs?

A
  1. produces cytokines that stimulate CTL differentiation

2. enhances ability of APCs to stimulate CTL differentiation

6
Q

What are CD8’s stimulated to differentiate into?

A

Cytotoxic T lymphocytes (CTLs) and some memory cells

7
Q

CD8 CTLs recognize Ags in the tissues and respond how?

A

by killing the target cells where the Ag is produced

8
Q

What are the two signals that lead to activation of CTLs?

A

Signal 1 = naive CD8 recognize Ags

Singal 2 = CD28-CD80 costimulation leads to proliferation and differentiation into effector CTLs

9
Q

Activated CTLs contain numerous granules called lysosomes, these contain what and what is their function?

A

perforin and granzymes, used by the cells to kill other cells

10
Q

What cytokine do activated CTLs secrete mainly, what does this cytokine do?

A

IFN-gamma; activates macrophages

11
Q

What transcriptional factor is involved with CTL differentiation? What is it’s function?

A

T-bet; regulates transcription of genes encoding perforin, granzymes and IFN-gamma

12
Q

Are CD4 helper T cells more important in generation of CD8 memory T cells or in differentiation of naive CD8 T cells to effector CTLs?

A

Generation of CD8 memory T cells

13
Q

How do CD4 helper T cells enhance activation?

A

they provide signal 3 in the form of cytokines

14
Q

APC licensing occurs when CD4 T cell recognizes what?

A

Ag presented by MHC class II, delivers activating signals through CD80/CD86 and CD40

15
Q

Activated CD4 Th cells express what? what do they bind to?

A

express CD40L; Binds to CD40 on Ag loaded DCs

16
Q

What causes APCs to be more efficient at stimulating the differentiation of CD8 T cells?

A

CD40-CD40L interaction which upregulates expression of CD80/CD86 on the APC

17
Q

What are the cytokines involved in CTL activation?

A

IL-2, IL-12, IL-15, IL-21