Innate Immunity Flashcards
(34 cards)
What are the components of innate immunity?
Epithelial barriers (defensins and cathelicidins), circulating and tissue cells, plasma proteins (complement, cytokines, etc)
What are defensins?
toxic cationic peptides
What are cathelicidins?
toxic, neutralizing proteins
What types of PAMPs are associated with viruses?
ssRNA, dsRNA, CpG sections in DNA
What types of PAMPs are associated with all bacteria?
Pilin, Flagellin and Mannan
What types of PAMPs are associated with gram-negative bacteria?
LPS, lipoteichoic acid
What types of PAMPs are associated with fungi?
Mannan and dectin glucans
What are toll-like receptors (TLR)?
PRRs that are embeded in the plasma membrane or endosomal membranes
Where is the TLR1-TLR2 heterodimer found and what does it recognise?
cell membrane; bacterial lipopeptides
Where is the TLR2 homodimer found and what does it recognise?
cell membrane; bacterial peptidoglycan
Where is the TLR4 homodimer found and what does it recognise?
cell membrane; LPS
Where is the TLR5 homodimer found and what does it recognise?
cell membrane; bacterial flagellin
Where is the TLR2-TLR6 heterodimer found and what does it recognise?
cell membrane; bacterial lipopeptides
Where is the TLR3 homodimer found and what does it recognise?
endosome membrane; dsRNA
Where is the TLR7 homodimer found and what does it recognise?
endosome membrane; ssRNA
Where is the TLR8 homodimer found and what does it recognise?
endosome membrane; ssRNA
Where is the TLR9 homodimer found and what does it recognise?
endosome membrane; CpG DNA
What is the recognition portion of the TLRs composed of?
Leucine rich repeat motifs
Where are NOD-like receptors found and what do they recognise?
in the cytoplasm; bacterial components and damaged host cells
Where are RIG-like receptors found and what do they recognise?
in the cytoplasm; viral RNA
What is TIR?
Toll/IL-1 receptor. It transmits the signal when a TLR is activated
What is NLRP3 Inflammasome?
NLRP3 + ASC + innactive caspase. Allows for the production of IL-1 beta, which causes accute inflammation
What are natural killer cells?
lymphocyte-like cells that recognise and directly kill infected, stressed or malignant cells and release inflammatory cytokines (especially IFN gamma)
What is the inhibitory signal for NK cells?
Immunoreceptor tyrosine-based inhibition motif (ITIMs) recognise MCH class I
