PRR Families

Question 1

How are a wide variety of PAMP ligands recognized?

Answer 1

families of PRRs

Question 2

What are the 5 main PRR families?

Answer 2

TLR/ CLR/ NLR/ RLR/ ALR

Question 3

what happens when PRRs bind to PAMPs?

Answer 3

signalling pathways initiated- contributing to innate/ inflammatory responses

Question 4

Where are TLRs located?

Answer 4

Plasma membrane/ membranes of endosomes/ lysosomes

Question 5

What is a component of the TLR exterior domain?

Answer 5

LRR = leucine-rich repeats

Question 6

What is the interior domain of TLR called?

Answer 6

TIR domain = toll interleukin receptor

Question 7

What happens after ligand binds to TLR exterior domain?

Answer 7

ligand (PAMP/ DAMP) induced TLR dimerization

Question 8

How many TLRs are there?

Answer 8

13

Question 9

What are dimers with extracellular leucine-rich domains that bind PAMPS/ DAMPS?

Answer 9

TLRs

Question 10

Since TLRs recognize many different pathogens, what determines what each TLR will bind?

Answer 10

= location
extracellular ligands- PM
ligands released by endocytosed microbes- endosomes/ lysosomes

Question 11

What is the ligand of TLR2?

Answer 11

peptidoglycan

Question 12

What microbe would peptidoglycan be on?

Answer 12

gram-positive bacteria

Question 13

What is the ligand of TLR3?

Answer 13

double-stranded RNA

Question 14

What microbe is double-stranded RNA on?

Answer 14

viruses

Question 15

What is the ligand of TLR4?

Answer 15

Lipopolysaccharide

Question 16

What is the microbe target of TLR4?

Answer 16

gram-negative bacteria (lipopolysaccharide)

Question 17

What is the ligand of TLR5?

Answer 17

Flagellin

Question 18

What microbe is flagellin on?

Answer 18

bacteria

Question 19

What microbe is lipopolysaccharide on?

Answer 19

gram-negative bacteria

Question 20

What does TLR binding of PAMP activate?

Answer 20

signalling pathways

Question 21

Where are adaptor proteins recruited to by the different TLRs?

Answer 21

Toll/IL-1R = TIR domain

Question 22

What are the 3 TLR activated pathways?

Answer 22

NF-KB/ IRF (interferon regulating factor)/ MAP Kinase pathway

Question 23

What TLR-activated pathway is responsible for transcription factor activation/ innate/ inflammatory gene activation?

Answer 23

NF-KB

Question 24

What TLR-activated pathway is responsible for the activation of genes encoding IFNa/b and viral compounds?

Answer 24

IRF/ interferon regulating factor

Question 25

What TLR-activated pathway is responsible for the activation of downstream transcription factors (AP-1)/ activator protein controls differentiation/ apoptosis?

Answer 25

MAP Kinase

Question 26

What are the 2 adaptors recruited to activated TLR dimers?

Answer 26

MyD88/ TRIF

Question 27

What do the adaptors MyD88/ TRIF do when recruited to TLR dimer?

Answer 27

bind multiple components/ generate scaffold/ initiate signalling pathway

Question 28

What are the downstream components of the pathway?

Answer 28

activation/ transcription of desired genes

Question 29

What are the 10 steps in TLR signalling?

Answer 29

1. Bind ligand 2. Receptor dimerization 3. Recruit adaptor protein 4. Recruit kinases 5. Phosphorylation 6. Activate MAPK pathway 7. Activate complexes 8. Translocate to nucleus 9. Activation/ gene transcription 10. Target production- cytokines/chemokines/ antimicrobial

Question 30

What PRR recognizes carbohydrate components of fungi/ parasites/ viruses?

Answer 30

CLR - C-type lectin receptor

Question 31

What does the transcription triggered by CLR signalling pathways induce?

Answer 31

expression of proinflammatory cytokines = IL-1B/ TBF/ IL-23

Question 32

What proinflammatory cytokines are produced through CLR pathway activation?

Answer 32

L-1B/ TBF/ IL-23

Question 33

What PRR family do NOD1/ NOD2 belong to?

Answer 33

NLR

Question 34

What part of the cell is NLR associated with?

Answer 34

endosome/ strictly within cell

Question 35

What receptors initiate autophagy by forming autophagosomes?

Answer 35

NLR: NOD1/ NOD2

Question 36

What receptor type recognizes viral double-stranded RNAs?

Answer 36

RLR = RIG1

Question 37

What part of the RLR receptor binds RNA?

Answer 37

helicase domain

Question 38

Where are RLRs located?

Answer 38

cytoplasm

Question 39

What is the adaptor molecule of RLRs?

Answer 39

MAVS

Question 40

What PRRs can both initiate NF-KB pathway?

Answer 40

TLR/ RLR

Question 41

What cytosolic receptors bind bacterial/ viral double-stranded DNA?

Answer 41

ALRs

Question 42

What does the binding of multiple ALRs to dsDNA via pyrin domains yield?

Answer 42

Inflamasomes

Question 43

What do inflammasomes generate?

Answer 43

pro-inflammatory cytokines IL-1B/ IL-18

Question 44

PRR signalling activates the expression of genes for what 5 major things?

Answer 44

Antimicrobial proteins Type 1 interferons Cytokines Chemokines Enzymes

Question 45

What produced by PRR signalling has very potent antiviral activity?

Answer 45

Type 1 interferons

Question 46

What inhibits virus replication/ activates NK cells/ regulates activity of macrophages/ T cells?

Answer 46

Interferons a/b

Question 47

What are produced by virus-infected cells/ macrophages/ dendritic cells/ NK cells?

Answer 47

Interferons a/b

Question 48

What kind of molecule is Interleukin-1?

Answer 48

cytokine

Question 49

What are 2 examples of cytokines?

Answer 49

Interleukin 1/ TNF-a

Question 50

What cytokine activates macrophages/ vascular permeability/ fever?

Answer 50

TNF-a

Question 51

What is an example of a chemokine?

Answer 51

IL-8

Question 52

What does IL-8 do?

Answer 52

chemoattract cells to infection site

Question 53

What are 2 enzymes produced by PRR signalling paths?

Answer 53

iNOS/ COX2

Question 54

What functions as protein hormones?

Answer 54

Cytokines