Inflammasomes and antimicrobial immunity Flashcards Preview

Module 2 > Inflammasomes and antimicrobial immunity > Flashcards

Flashcards in Inflammasomes and antimicrobial immunity Deck (55):
1

Give examples of extracellular bacteria?

staph; strep; klebsiella

2

Give an example of cell surface bacteria

E.coli

3

Give eamples of intra-vacuolar bacteria?

salmonella; legionella; mycobacterium

4

Give examples of cytosolic bacteria?

listeria; shigella

5

What type of protein are injectisomes related to?

flagellar rotors

6

What is the gram stain of salmonella?

gram neg

7

Why is the injectisome useful for the innate immune system to recognise?

highly conserved

8

What type of pathogen is listeria?

gram pos cytosolic pathogen

9

How does listeria move wtihin the cell and spread to adjacent cells?

host actin machinery and produce listeriolyin O

10

What is the function of listeriolyin O?

pore forming toxin

11

What cells does TB live and replicate inside?

alveolar macrophages

12

What is essential for the virulence of TB?

ESX secretion system

13

What cytokines protect against M.tb?

IL-12; IFNy and IL-1b

14

What do AIM2 receptors recognise?

cytosolic dsDNA

15

Describe the PYHIN family proteins?

can activate inflammasomes; sontain can N-terminal pyrin domain but lack the LRR domain of NLRs instead have HIN domain

16

Name a member of the PYHIN family?

AIM2

17

What cells does IL-18 act upon?

NK cells and T cells

18

What cytokine does IL-18 induce NK cells and T cells to make?

IFNy

19

What is the result of IFN-induced cell autonomous defensce?

iNOS; NADPH oxidase; autophagy; GBP

20

What is an inflammasome?

a large multiprotein complex that activates caspase-1 via the adaptor protein Asc

21

How is pro-caspase 1 activated?

self-proteolytic cleavage into p20 and p10 active subunits

22

What are the inflammatory outcomes of inflammasome activation?

IL-1b and IL18 release; alarmin release; pyroptosis

23

What alarmins does inflammasome activation result in the release of?

IL-1a and HMGB1

24

What domain is responsible for recruiting Asc to the receptor?

pyrin domain

25

What domain links Asc to caspase -1?

CARD domains

26

What happens when there is a gain of function in caspase-1?

autonimmune/inflammatory diseases; fever syndromes

27

Why does gain of function in caspase-1 result in fever syndromes?

IL-1b acts on hypothalamus to cause fever

28

What does inflammasome pathways require?

priming of cells- expression of receptors and substrates

29

How does AIM2 cause inflammasome assembly?

HIN domains oligomerise around DNA leaving PYD open for binding to Asc which then polymerises and binds caspase1

30

What do NAIPs recognise?

T3SS rod or needle or bacterial flagellin

31

What do ligand bound NAIPs bind?

NLCR4

32

happens when NLRC4 is activated by NAIP?

able to activate caspase-1 by ASc or sometimes directly by its N-terminal CARD domain

33

What is the inflammasome assembly described as being like?

Prion-like

34

What type of bacteria do not have T3SS?

gram positive

35

How does listeria activate NLRP3?

produces toxin which produces pore resulting in K efflux and dissociation of NLrp3 chaperone proteins allowing its LRR domsns to join and bind Asc

36

What inflammasomes are activated by M.tb?

NLRP3 and AIM2

37

What are the features of pyroptosis?

osmotic swelling and bursting of cells; spillage of cellular contents and enhanced infalmmation

38

What protien is essential in pyroptosis?

gasdermin-D

39

What is the function of gasdermin-D?

forms pores in membranes

40

What cleaves gasdermin-D?

caspases 1,4,5

41

What is the functions of caspases 4 and 5?

cytosolic receptors for LPS

42

What is the mechanism of inflammasome activation by caspases 4 and 5?

non-canonical

43

How do caspase 4 and 5 result in inflammasome activation?

cleave gasdermin D which makes pores in membrane or by processing pannexin1 resulting K effluc and NLRP3 activation

44

What is the equivalent of caspases 4 and 5 in mice?

caspase 11

45

Why do cytosolic gram negative bacteria trigger pyroptosis?

result of direct activation of capse 4 by LPS

46

What 2 death domains does ASC consist of?

pyrin domain and CARD domain

47

What viral infections is AIM2 important in?

CMV vaccinia

48

What domain on caspases 4 and 5 binds to LPS?

CARD

49

What domain in NLRs mediates self-oligomerisation?

NOD domain

50

By what mechanism are IL-1b and IL18 released from the cell?

unconventional secretion- independent of the ER and golgi

51

What are the regultors of inflammasome assembly that modulate the interactions of death fold domains?

CARD-only proteins- COPs and PYD-only proteins (POPs)

52

How are COPs thought to work?

sequester caspase 1 thereby negative regulating inflammasomes

53

What is thought to be the function of caspase-12?

interacts with caspase 1 resulting in reduced caspase 1

54

What is the function of POPs?

binds ASC with its pyrin domain preventing its binding to other pyrin domains

55

What can induce POP1 expression?

TLR and IL-1R signalling