Cytotoxicity

Question 1

What do CTLs express

Answer 1

TCR and CD8

Question 2

What do NK cells express

Answer 2

No TCR, CD4 or CD8 but express multiple germ-line encoded activating and inhibitory receptors

Question 3

What can NK cells do

Answer 3

Kill virally infected and transformed cells without prior exposure to antigen (innate)

Question 4

The missing self hypothesis

Answer 4

NK cells detect down-regulation of class I

Question 5

What are KIRs

Answer 5

Killer cell Ig-like receptor - MHC class I - inhibiton - ITIMS

Question 6

What are NKG2As

Answer 6

Expressed as heterodimers with CD94 - ITIM - inhibitory - class I

Question 7

How do Tc and NK cells kill cellular targets

Answer 7

Induce apoptosis

Question 8

What is the role of perforin?

Answer 8

Polymerises to form pores in target cell membranes (increase in Ca2+ stimulates)

Question 9

What does myeloid cytotoxicity consist of?

Answer 9

Neutrophils, eosinophils and macrophages

Question 10

What happens when phagocytosis occurs in myeloid cells

Answer 10

Activates NADPH oxidase and the ‘oxidative burst’