Innate Immunity Part I- Lecture 4

Question 1

Where do you find TLR 2,6?

Answer 1

Peptidoglycan/ Gram-positive bacteria

Question 2

Where do you find TLR 4?

Answer 2

LPS/ Gram-negative bacteria/endotoxin

Can activate both MyD88 and TRIF pathways to activate transcription factors

Question 3

Where do you find TLR 5?

Answer 3

Flagella

Question 4

Where do you find TLR 9?

Answer 4

CpG

Question 5

Where do you find TLR 3?

Answer 5

dsRNA

Question 6

Where do you find TLR 7, 8?

Answer 6

ssRNA

Question 7

Which are the Extracellular TLR’s?

Answer 7

1,2,4,5,6

1, 2, 5, 6- activate MyD88 pathway
4- activates both MyD88 and TRIF pathways

Question 8

Which are the Intracellular TLR’s?

Answer 8

3, 7, 8, 9

7, 9- activate MyD88 pathway

3- activates TRIF pathway

Question 9

What are the ligands for NLR’s and when they bind what happens?

Answer 9

Intracellular proteins

Formation of the inflammasome and caspase-mediated apoptosis

Question 10

What are the ligands for scavenger receptors?

Answer 10

Negatively charged bacterial components

Question 11

What are the ligands for Lectin receptors and whats 1 key fact for each the Lectin receptor and the Ligand?

Answer 11

Carbohydrates

NB! Eukaryote: terminal sugar is galactose or sialic acid
Ligand from Bacterial/PAMP: terminal sugar is mannose

Question 12

Ultimately, what occurs after the binding of either NLR’s, Scavengers, or Lectin?

Answer 12

All receptors lead to signaling pathways ultimately resulting in cytokine mediated inflammation, and/or phagocytosis

Question 13

For DAMPs HMGB1, RAGE, and HSPs, what does each bind to?

Where are the receptors found?

Answer 13

HMGB1 binds to RAGE

HSPs bind to CD91

*Receptors are found on dendritic cells

Question 14

What is the source of antimicrobial peptides?

Answer 14

Epithelial cells or granule containing leukocytes

Question 15

What are 2 antimicrobial peptides and what are their functions?

Answer 15

Defensins: direct toxicity, kill microbes via disruption of membrane.

Cathe’licidins: direct toxicity, released by neutrophils predominately.

Question 16

What is the main function of antimicrobial peptides?

Answer 16

• Kill microbes

- Attract immunological cells to help eliminate microbes

Question 17

What is the relationship between Macrophage Resident Cell and NK cells?

Answer 17

1) Release of IL 12 from Macrophage Resident Cell induces NK cell release of IFN gamma
2) Activation of Macrophage Resident Cell to kill phagocytosed pathogens

Question 18

What is an inhibitor of NK cells and what occurs if this is not present?

Answer 18

MHC class I

If not present, then NK cells kill it