cell mediated cytotoxicity

Question 1

How do CTL precursors get activated?

Answer 1

by interacting with a “licensed” APC

Question 2

What cell surface marker serves as a high affinity IL-2 receptor?

Answer 2

CD25+

Question 3

When does a naive CTL-P start to express IL-2 or IL-2R (CD25)?

Answer 3

after activation

Question 4

What does a naive CTL-P express to help keep it in the lymph node?

Answer 4

L-selectin

CCR7

also:

CD44 and LFA-1 (low levels)

Question 5

What does the effector CTL express?

Answer 5

High affinity IL-2R (CD25)

LOW levels of L-selectin and CCR7

HIGH levels of CD44 and LFA-1 (to home in on inflammation)

starts to produce perforin and granzyme—>capable of cytotoxic killing

Question 6

What do memory T-cells require for reactivation:

Answer 6

IL-2

**not necessarily Th1’s

Question 7

Three main systems for cytotoxic killing:

Answer 7

perforin and granzyme

FAS-FASL —> apoptosis

TNF production

Question 8

Whats the difference between CD56low and CD56high?

Answer 8

two types of NK cells

low have granules and are most effective killers of target cells (90% of nk’s in blood)

high release cytokines but have no granules (10% of nk’s in blood)

Question 9

Which cytokines stimulate NK activity?

Answer 9

IFN-a, IFN-B, IFN-y, TNF-a, IL-15

Question 10

What is CD16 on NK cells?

Answer 10

recognizes IgG

Question 11

Two types of NK receptors?

Answer 11

Lectin like (NKG2)

• mostly activating EXCEPT NKG2A (inhibitory)
• NKG2D—D=DEATH

KIR (killer cell immunoglobulin-like receptor)
-mostly inhibitory

Question 12

What do NKG2’s bind to?

Answer 12

HLA-E and MHC I-like molecules

Question 13

What do KIR’s bind to?

Answer 13

HLA-A,B,C

Question 14

How do NK cells get activated?

Answer 14

bump into an inhibitory signal (ie. NKG2A) at least once (to prove it can be inhibited and won’t go rogue)

**this prevents autoimmunity

Question 15

Review slide 29 for….

Answer 15

Antibody-Dependent Cell mediated Cytotoxicity

ADCC

Question 16

Effector molecules of CD8+?

Answer 16

IL-2R (a lot)

L-selectin/CCR7 (a little)

CD44/LFA-1 (a lot)

Perforin/Granzymes

Question 17

Effector molecules of NK’s?

Answer 17

INF-y (increases Th1’s, decreases Th2’s)
-makes angry Mac’s

Induces IL-12 from Mac’s/Dend’s

Question 18

Which cells give APC’s their “license”?

Answer 18

Th1

Th17

Question 19

Compare CD8s and NKs:

Antigen response:

Memory:

MHC restriction:

Thymus education:

Answer 19

CD8s NKs

TCR/CD3–MHC I cells lacking MHC I
LFA-1—-ICAM
FASL—FAS
secrete TNF

yes ?

MHC I none

yes no

Question 20

Only NKG2 (lectin like) that is inhibitory?

What is its ligand?

Answer 20

NKG2A

HLA-E

Question 21

Only NKG2 that doesn’t bind HLA-E?

What does it bind?

Answer 21

NKG2D

ULBPs, MIC A/B

Question 22

Only KIR that is activating?

What does it bind?

Answer 22

KIR2DS1

HLA-C2

Question 23

Antibody dependent cell mediated cytotoxicity:

What cells involved? How do they bind?

Answer 23

NK's
Macs
Monos
Neuts
Eos

bind Ig via Fc receptor

Question 24

Which cells participate in ADCC with enzyme release killing?

Answer 24

Macs
Eos
Neuts

Question 25

Which cells participate in ADCC with TNF release?

Answer 25

NK’s
Monos
Macs

Question 26

Which cells participate in ADCC with perforin?

Answer 26

NK’s

Eos

Question 27

Which cells participate in ADCC with granzyme?

Answer 27

NKs