T Cell Mediated Immunity Flashcards Preview

SFM Exam 2 > T Cell Mediated Immunity > Flashcards

Flashcards in T Cell Mediated Immunity Deck (17)
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1
Q

Activated Peripheral DCs up-regulate __ expression and lose ___ markers

A
  • CCR7

- adhesive

2
Q

DCs __ as they migrate

A

Mature

3
Q

While migrating, activated DCs increase expression of what 3 receptors/molecules/costimmulators?

A
  • MHC class II
  • CD80/B7
  • LFA-1
4
Q

What can be found on surface of Cytotoxic T Cells?

(1) signaling complex?
(2) CD8 or CD4?
(3) MHC Class?
(4) Others?

A

(1) TCR/CD3 signaling complex including zeta
(2) CD8+
(3) MHC class 1
(4) CD28+, LFA-1, CCR7, L-selectin

5
Q

What can be found on surface of T Helper Cytokine Secreting Cells?

(1) signaling complex?
(2) CD8 or CD4?
(3) MHC Class?
(4) Others?

A

(1) TCR/CD3 signaling complex including zeta
(2) CD4+
(3) MHC class 1 and 2
(4) CD28+, LFA-1, CCR7, L-selectin

6
Q

What is the function of L-selectin?

A

initial weak adhesion of naive T cells to HEV in lymph node

7
Q

What is the function of CCR7?

A

Activation of integrins and chemokinesis

8
Q

What is the function of LFA-1 binding to ICAM on surface of endothelial cells?

A

Stable arrest on HEV in lymph node

9
Q

Which cell type has greater colonal expansion into effector cells: CD4+ or CD8+?

A

CD8+

increase 100,000x compared to 100-1000x increase in CD4+

10
Q

What is the first signal involved in activation of T cells?

A

CD4+/8+ TCR binding to MHC class on APC (binds to invariant portion of MHC)

11
Q

What co-stimulatory molecule is constitutively expressed on T cells?

A

CD28

12
Q

What co-stimulatory molecule is constitutively expressed on DCs?

A

CD40

13
Q

What provides the second signal involved in activation of T cells?

A

Binding of the co-stimulatory molecules

CD28 -> B7/CD80, CD40L -> CD40, PD-1 (with ITIM) -> PD-L1

14
Q

TCR/HLA Ag recognition changes integrin confirmation of LFA-1 from __ to __ affinity

A

Low to High

allows for clustering of adhesion molecules and firm adhesion for immune synapse

15
Q

What is the function of the second signal in activating T cells?

A

Maintains the specificity of the response to the specific epitope – tight binding that allows for proliferation of T cells

16
Q

What receptor is constitutively expressed in a low affinity state on mature, naive T cells?

A

IL-2Rβγc

17
Q

What happens to IL-2R on T cell after cell becomes activated?

A

Upregulation of additional high affinity chain, α chain (CD25), making the receptor IL-2Rαβγc