Innate Immunity Part I- Lecture 4 Flashcards
Where do you find TLR 2,6?
Peptidoglycan/ Gram-positive bacteria
Where do you find TLR 4?
LPS/ Gram-negative bacteria/endotoxin
Can activate both MyD88 and TRIF pathways to activate transcription factors
Where do you find TLR 5?
Flagella
Where do you find TLR 9?
CpG
Where do you find TLR 3?
dsRNA
Where do you find TLR 7, 8?
ssRNA
Which are the Extracellular TLR’s?
1,2,4,5,6
1, 2, 5, 6- activate MyD88 pathway
4- activates both MyD88 and TRIF pathways
Which are the Intracellular TLR’s?
3, 7, 8, 9
7, 9- activate MyD88 pathway
3- activates TRIF pathway
What are the ligands for NLR’s and when they bind what happens?
Intracellular proteins
Formation of the inflammasome and caspase-mediated apoptosis
What are the ligands for scavenger receptors?
Negatively charged bacterial components
What are the ligands for Lectin receptors and whats 1 key fact for each the Lectin receptor and the Ligand?
Carbohydrates
NB! Eukaryote: terminal sugar is galactose or sialic acid
Ligand from Bacterial/PAMP: terminal sugar is mannose
Ultimately, what occurs after the binding of either NLR’s, Scavengers, or Lectin?
All receptors lead to signaling pathways ultimately resulting in cytokine mediated inflammation, and/or phagocytosis
For DAMPs HMGB1, RAGE, and HSPs, what does each bind to?
Where are the receptors found?
HMGB1 binds to RAGE
HSPs bind to CD91
*Receptors are found on dendritic cells
What is the source of antimicrobial peptides?
Epithelial cells or granule containing leukocytes
What are 2 antimicrobial peptides and what are their functions?
Defensins: direct toxicity, kill microbes via disruption of membrane.
Cathe’licidins: direct toxicity, released by neutrophils predominately.
