Lecture 27: Intracellular Receptors

Question 1

What alerts the innate immune system to strangers and danger ?

Answer 1

PAMPs and DAMPS

Question 2

When are DAMPS released ?

Answer 2

In dangerous situations like stress, injury, cell death

Question 3

What can detect PAMPS and DAMPS ?

Answer 3

1. CLR
2. TLR
3. NLR
4. RLR

Question 4

What are CLRs ?

Answer 4

Transmembrane proteins localised at the plasma membrane

Question 5

What do CLR recognise?

Answer 5

Glycans from the wall of fungi and some bacteri

Question 6

What do CLR activate ?

Answer 6

Kinase syk and CARD9/MALT1/Bcl-10 adapter complex

Question 7

What are TLRs

Answer 7

Transmembrane proteins localised either at the plasma membrane or in endosomes

Question 8

What do TLR activate ?

Answer 8

MAP kinase, NFkappaB and IRF

Question 9

What are NLR ?

Answer 9

Cytoplasmic sensors

Question 10

What do NLPRs recognise ?

Answer 10

Bacterial, viral, parasitic and fungal PAMPS

Question 11

What does AIM2 detect ?

Answer 11

Viral and bacterial DNA

Question 12

What does AIM2 do ?

Answer 12

1. Forms inflammasomes
2. Activates caspase-1-mediated processing and activation of pro-interleukins IL-1B and IL18

Question 13

What do NOD1 and NOD2 recognise ?

Answer 13

Bacterial peptidoglycan

Question 14

What are RLRs ?

Answer 14

Cytoplasmic sensors of viral RNA

Question 15

What do RLRs signal via ?

Answer 15

MAVS

Question 16

What do RLRs trigger ?

Answer 16

Antiviral responses including the production of type 1 interferons

Question 17

How many NLRS in human genome ?

Answer 17

22

Question 18

What do all NLRs contain ?

Answer 18

1. N-terminal effector domain
2. Nucleotide binding domain
3. Leucine rich repeats

Question 19

When is apoptosome triggered ?

Answer 19

Following detection of cytosolic cyt. c by Apaf-1

Question 20

When are inflammasomes triggered ?

Answer 20

Following detection of PAMP or DAMP by NLR

Question 21

What do apoptosomes and inflammasome form ?

Answer 21

Large, multiprotein complexes to facilitate caspase activation

Question 22

What to apoptosomes activate ?

Answer 22

Caspase 9

Question 23

What do inflammasomes activate ?

Answer 23

Caspase 1

Question 24

What is apoptosis ?

Answer 24

Programmed cell death, immunologically silent

Question 25

What is pyropoptosis ?

Answer 25

Inflammatory cell death, IL-1B release inflammation

Question 26

What can inflammasomes in cells be visualised as ?

Answer 26

Distinct specks r puncta

Question 27

How is caspase 1 activated ?

Answer 27

NLRP3 inflammasome

Question 28

What are the PYTHIN proteins ?

Answer 28

Pyrin and HIN-200 domain containing

Question 29

What detects dsDNA in the cytosol ?

Answer 29

AIM2

Question 30

What does caspase 11 sense ?

Answer 30

Intracellular LPS

Question 31

What does caspase 11 activate ?

Answer 31

Non-canonical inflammasome

Question 32

What was caspase 11 identified as ?

Answer 32

3rd regulatory signal for non-canonical inflammasome

Question 33

What can active caspase 11 cleave ?

Answer 33

GSDMD

Question 34

What does the cleavage of GSDMD lead to ?

Answer 34

Pyroptosis

Question 35

What can caspase 11 not do ?

Answer 35

IL-1B or IL18 into their mature active forms

Question 36

What do RIG-I receptors recognise ?

Answer 36

dsRNA containing 5’PPP or 5’PP

Question 37

What do MDA5 form ?

Answer 37

Filaments along dsRNA backbone