Lecture 8: Natural Killer Cells

Question 1

What are natural killer cells good at ?

Answer 1

Killing virally infected cells

Question 2

What type of response do you want to a viral infection and why ?

Answer 2

Th1 as it produces intereferon gamma

Question 3

What is an effector cell ?

Answer 3

Carry out end-stage jobs in the innate immune system

Question 4

What are the regulators of the adaptive immune system ?

Answer 4

Cell-cell contact or cytokines

Question 5

What are natural killer cells distinguished by ?

Answer 5

Cell surface molecules

Question 6

What is a marker on all cells

Answer 6

CD3

Question 7

What is the marker on natural killer cells ?

Answer 7

CD56 and or CD16

Question 8

What are natural killer cells characterised by ?

Answer 8

Granules in their cytoplams

Question 9

Do natural killer cells have thymus development ?

Answer 9

NO

Question 10

What are natural killer cells important in ?

Answer 10

Effector cells in viral infections and cancer where they mediate cytotoxicity

Question 11

What do natural killer cells produce ?

Answer 11

Cytokines which activate other cells of the immune system

Question 12

What do natural killer cells recognise and kill ?

Answer 12

Tumour cells in vitro and in vivo

Question 13

What activates natural killer cells ?

Answer 13

IL2

Question 14

What does IL2 which activates NK cells generate ?

Answer 14

Lymphokine activated killers (LAK)

Question 15

What do NK cells produce ?

Answer 15

1. IFN-gamma
2. TNF-alpha
3. TGF-beta
4. G-CSF
5. GM-CSF
6. IL3

Question 16

What are the first cytokines produced by macrophages and dendritic cells ?

Answer 16

1. IFN-gamma
2. IL12
3. TNF-alpha

Question 17

What does NK cells regulate ?

Answer 17

1. Haemopoiesis
2. Antibody isotype switching

Question 18

How does NK regulate haemopoiesis ?

Answer 18

Through colony stimulating factors and IL3

Question 19

What does antibody isotype switching occur through ?

Answer 19

IFN-gamma

Question 20

How do cytotoxic effector cells kill their targets ?

Answer 20

1. Necrosis
2. Apoptosis

Question 21

What is necrosis ?

Answer 21

Non-physiological insult to cell which results in membrane damage and osmotic lysis. Associated with inflammation as cell contents leak out

Question 22

What is apoptosis ?

Answer 22

Physiological form of cell death

Question 23

How is programmed cell death activated ?

Answer 23

1. DNA fragmentation
2. Formation of apoptotic bodies

Question 24

What do granules contain to kill cells ?

Answer 24

1. Perforin
2. Granzymes

Question 25

What is perforin ?

Answer 25

Pore forming proteins

Question 26

What is granzymes ?

Answer 26

Serine proteases

Question 27

What happens upon target cell binding ?

Answer 27

Cytotoxic cell rearranges its organelles to bring cytotoxic granules to the immunological synapse with target cell

Question 28

What is lymphotoxin ?

Answer 28

Membrane bound version of TNF

Question 29

What can cytotoxic cells do to themselves ?

Answer 29

Recycle themselves and kill more target cells

Question 30

What do T cells and NK cells recognise ?

Answer 30

MHC 1 antigen

Question 31

What are t cells activated by ?

Answer 31

MHC I

Question 32

What are NK cells inhibited by ?

Answer 32

MHC I