BLOCK A Pathogen Recognition

Question 1

Pattern Recognition Receptors (PRRs)

Answer 1

Receptors that recognize pathogen-associated molecular patterns (PAMPs) by germline-encoded receptors of the innate immune system.

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Question 2

Toll-like Receptors (TLRs)

Answer 2

Family of PRRs recognizing molecular patterns not found in healthy vertebrate cells.

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Question 3

Inflammasomes

Answer 3

Multiprotein complexes that drive pro-inflammatory cytokine production and induce cell death.

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Question 4

Innate Immunity

Answer 4

Early phase of the host response that predates separation of animal and plant lineages.

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Question 5

Acquired Immunity

Answer 5

Generated by specific lymphocytes, discriminates between individual pathogens, and is associated with ‘memory’.

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Question 6

Mucins

Answer 6

prevents adhesion to epithelium by microorganisms.

Question 7

Lysozyme

Answer 7

Glycosidase that attacks peptidoglycan in bacterial cell wall.

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Question 8

Defensins

Answer 8

Disrupts the cell membranes of bacteria and fungi via pore formation.

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Question 9

Cathelicidins

Answer 9

Disrupt cell membrane of wide range of microorganisms.

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Question 10

Histatins

Answer 10

Active against pathogenic fungi.

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Question 11

RegIII family

Answer 11

Family C-type lectins targeting peptidoglycans, promoting pore formation.

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Question 12

Mannose-binding lectin

Answer 12

Recognizes sugars like mannose and fucose.

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Question 13

Ficolin

Answer 13

Recognizes oligosaccharides containing acetylated sugars.

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Question 14

C-reactive protein

Answer 14

Recognizes phosphorylcholine.

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Question 15

NOD-Like receptors (NLRs)

Answer 15

Cytoplasmic receptor proteins that are intracellular sensors of bacterial invasion and cellular damage.

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Question 16

NLRP3

Answer 16

Forms an inflammasome complex that includes the adapter protein ASC.

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Question 17

ASC

Answer 17

Apoptosis-associated speck-like protein containing a CARD, recruits and activates caspase-1.

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Question 18

What do both TLR and iL-1R have?

Answer 18

The same form of DOMAIN (TIR)

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Question 19

How do Toll and IL-1 receptors differ?

Answer 19

IL-1R has Ig-like domain whilst TLR (Toll) has leucine rich repeats

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Question 20

Both Toll and IL-1 play a role in inflammatory response with

Answer 20

TLR recognising PAMPS and IL-1R brining to the pro inflammatory cytokine IL-1

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Question 21

MyD88

Answer 21

Adaptor protein triggering NF-κB activation and cytokine production in TLR signaling.

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Question 22

TRIF

Answer 22

Adaptor protein involved in TLR signaling leading to type I interferon production.

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Question 23

LPS

Answer 23

Lipopolysaccharide, recognized by TLR4 in bacterial infections.

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Question 24

MAPK pathways

Answer 24

Activated in TLR signaling, contributing to inflammation, cell survival, and apoptosis.

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Question 25

innate immunity

Answer 25

Discriminates between groups of pathogens. ## Footnote Predates separation of animal and plant lineage.

Question 26

Adaptive immunity

Answer 26

Generated by specific lymphocytes (type of white blood cell). ## Footnote Discriminates between individual pathogens.

Question 27

How many PRR's are known?

Answer 27

100 BUT, 4 main ones to study in-depth. ## Footnote No footnote

Question 28

What are the type of PRRs

Answer 28

C type lectin family, Scavenger receptors, Complement and Fc receptors, TOLL-like receptors. ## Footnote No footnote

Question 29

C type lectin family

Answer 29

Recognises b-1,3-linked glucans, common component of fungal cell walls. ## Footnote No footnote

Question 30

Mannose receptor is apart of what family?

Answer 30

C type lectin family. ## Footnote No footnote

Question 31

Mannose receptor

Answer 31

May recognise mannose-containing structures on pathogens but also plays a role in clearance of host proteins. ## Footnote No footnote

Question 32

Scavenger

Answer 32

Structurally heterogenous. Recognises various anionic polymers and acetylated low density lipoproteins. ## Footnote No footnote

Question 33

Complement and Fc receptors

Answer 33

Recognise complement-coated and antibody coated organisms. ## Footnote No footnote

Question 34

TLR4 PATHWAYS

Answer 34

Key outcomes of TLR4 signalling - Pro-inflammatory cytokines (TNF-A, IL-6, IL-1B) Via NF-kB activation, Type 1 interferons, Activation of MAPK pathways which contribute to inflammation, Antimicrobial defence. ## Footnote No footnote

Question 35

PRRs are key to....... And provide...... (3 terms)

Answer 35

Immune surveillance and inflammation. ## Footnote No footnote

Question 36

Difference between Heterodimers and Homodimers

Answer 36

Heter = when two difference receptors dimerise, Homo = same receptors dimerise. ## Footnote No footnote

Question 37

In order for Signal transduction to occur TLR4 pathway, TLR-4 recognises..........

Answer 37

LPS in association with the accessory protein MD-2. Stabilisation leads to signal transduction. ## Footnote No footnote