Cell-Mediated Toxicity--Diebel Flashcards Preview

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Flashcards in Cell-Mediated Toxicity--Diebel Deck (16)
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1
Q

This receptor interaction is important in the licensing of APC by CD4+ T-cells

A

CD40/CD40L interaction

2
Q

This receptor interaction is important in activating a CTL-precursor into a CTL

A

CD28/B7 interaction with licensed DC

3
Q

How does a CD4+ T-cell “license” a DC?

A

CD40/CD40L interaction signals DC to also present MHC-I

this is “licensing”–permitting it to present on both MHC

*normally we think DC activate CD4+, and that is true. but CD40/CD40L interaction is important for licensing while MHC/CD3 interaction is important in the opposite direction*

4
Q

CD25

A

high affinity IL-2 receptor

*expressed only on CTLs, not CTL-precursors*

5
Q

L-selectin and CCR7

A

expressed by naïve CTL

*they bind and have affinity in nodes, keeps them put*

6
Q

CD44 and LFA-1

A

found only on CTL

*tropic for inflammed tissue*

7
Q

How do CTLs kill bad cells?

A

perforin holes, granzyme cleaveage of caspaces

FAS-FASL interaction –> caspace cascade

8
Q

What is the normal blood concentration of NK-cells?

A

5-10% of lymphocytes

9
Q

What are the two subtypes of NK-cells?

A

CD56-low (90%)

*killer cells*

CD56-high (10%)

*cytokine releasing cells*

10
Q

CD56

A

differentiates killer NK-cells (90%) from cytokine-releasing NK-cells (10%)

11
Q

Killing mechanism of NK-cells

A

perforin + granzymes

FAS/FASL

*same as CTL*

12
Q

CD16

A

expressed by NK-cells

NK marker

*16 year old drivers are natural killers*

13
Q

Lectin-like receptors

  • what do they bind
  • activity
A

bind HLA-E and MHC-I-like molecules

-usually activating (except NKG2A–inhibitory)

14
Q

Immunoglobulin-like Receptors

  • what do they bind
  • activity
A
  • bind most MHC-I molecuels (HLA-A, -B, -C)
  • most are inhibitory
15
Q

NKG2A

NK-cell receptor

  • what does it bind
  • what does it do
A
  • binds HLA-E
  • supreme inhibitory signal (inhibits NK-cell even if other stimulatory signals are present)
16
Q

NKG2D

NK-cell receptor

  • what does it bind
  • what does it do
A
  • binds ULBPs, MICA/B
  • activation of NK-cells