9.2 Cytotoxic cells and antiviral responses

Question 1

name 2 of the most common types of cold

Answer 1

Rhinoviruses

Adenoviruses

Question 2

What is the classification of Rhinoviruses?

Answer 2

ssRNA

Baltimore group IV

Question 3

What is the classification of Adenoviruses?

Answer 3

dsDNA

Baltimore group IV

Question 4

What might facilitate extracellular recognition of viruses?

Answer 4

PAMPs

PRRs

Question 5

What might facilitate intracellular recognition of viruses?

Answer 5

TLRs
RG-I like receptors
Nod like receptors

Question 6

What is the broad function of interferons?

Answer 6

interfere with viral infections

Question 7

What are alpha interferons produced by?

Answer 7

plasmacytoid dendritic cells

monocytes

Question 8

What are alpha interferons used to treat?

Answer 8

Hep B and C

Question 9

What are beta interferons produced by?

Answer 9

many cell types not too specific

Question 10

What are beta interferons used to treat?

Answer 10

MS

Question 11

What are gamma interferons activated by?

Answer 11

IL-12

Question 12

What are gamma interferons important for?

Answer 12

Th1 driven immunity

Question 13

what role do type III interferons have in immunity?

Answer 13

anti-fungal / viral immunity

Question 14

What are ISGs?

Answer 14

interferon stimulated gene

Question 15

how can interferons / IDGs inhibit viruses?

Answer 15

protein synthesis
degradation of viral RNA (RNAse)
inhibition of viral gene expression (and virion assembly)
MHC-I upregulation
increase p53 activity

Question 16

What intracellular pathway do Thiazolide antivirals use?

Answer 16

PKR

Question 17

How can viruses turn off the IFN cascade?

Answer 17

TLR3 pathways

NEMO and NFkB pathways

Question 18

What does dysregulation of innate intracellular DNA sensing lead to?

Answer 18

auto-inflammatory and auto-immune disease

Question 19

What is STING?

Answer 19

stimulator of interferon genes

Question 20

What is SAVI?

Answer 20

STING associated vasculopathy with onset infancy

Question 21

What is the key method for viral recognition by CD8 T cells?

Answer 21

MHC-I loading

Question 22

What is cross-presentation?

Answer 22

CD8 I cytotoxic T cell killing
AND
Promotion of Th1 immunity

Question 23

What are the consequences of cross-penetration?

Answer 23

endogenous antigens CAN prime CD4

Exogenous antigens can prime CD8

Question 24

What are CTL?

Answer 24

Cytotoxic T Lymphocytes

Question 25

What stimulates proliferation of CTL?

Answer 25

engagement of peptide-loadded MHC clas I

Question 26

What do CTL do?

Answer 26

recognise peptide expressed on MHC class I

Question 27

What effect do viruses have on MHC class I?

What is the significance of this?

Answer 27

they interfere with it
infected cells have low MHCI

This prevents CTLs from recognising infected cells

Question 28

How can low MHC cells be eliminated?

Answer 28

NK cells target them

Question 29

What is the MOA for directly neutralising antibodies?

Answer 29

block virus / receptor interaction
block endocytosis
block release into cytoplasm
aggregate virus

Question 30

How do indirectly neutralising antibodies work?

Answer 30

induce classic complement cascade

bind to FCgammaRIII (CD16) receptors on NK cells, activating them

Question 31

What is ADEI?

Answer 31

antibody dependent enhancement of infection

Question 32

When does ADEI occur?

Answer 32

non-neutralising antiviral proteins facilitate virus entry into host cells

after first infection, antibodies are non-neutralising

on secondayr infection Fc domain of these antibodies allows entry into cell

Question 33

What is used as the prototype for ADEI?

Answer 33

Dengue

Question 34

Where does dengue replicate?

Answer 34

dendritic cells

Question 35

What does infection with Dengue generate?

Answer 35

neutralising Abs to infecting cells

Question 36

What is the mortality rate of Dengue haemorrhagic fever?

Answer 36

10-50%