Innate Immunity Flashcards
TLR-2
bacterial lipoglycans; peptidoglycans
cell surface
TLR-4
LPS
cell surface and endosomes
TLR-5
Flagellin
cell surface
TLR-9
unmethylated CpG oligonucleotides
endosomes
Detection of Extraceullular microbes
TLRs, NLRs, Mannose receptors, dectins (fungal glycans), complement system
TLR signaling - from extracellular foreign bodies
MyD88 -> IRAK -> NF-kB
NLR signaling
NLRP-3 inflammasome -> cleaves caspase-1 to activate it -> caspase 1 cleaves Pro-IL-1B to IL-1B…
IL-1B causes fever, acute inflammation and recruits neutrophils and monocytes to sites of infection
TLR signaling from endosomal TLRs
occurs mainly because of single stranded DNA or double stranded RNA
sensors: RIG-i, MDA5 (both work through MAVS in the mitochondria) and STING (in the ER)
results in activating NF-kB, Type I interferons and IRF7
Type I interferons
IFN-alpha and IFN-beta
IFN-gamma is type II
results: induce resistance to viral replication in all cells, increase expression of ligands for receptors on NK cells and activate NK cells to kill virus-infected cells
NK cell killing/activation
IL-12 from macrophages and then secrete IFN-gamma to further activate macrophages
NKG2D - receptor that activates NK cell to kill/secrete granules
ADCC - Fc receptor on NK cell bound to an antibody that recognizes the target cell
how do you turn off innate response
IL-10 secreted
IL-1 receptor antagonist
B-1 B cells
B lymphocytes in peritoneal cavity and mucosal tissues
produce IgM when they recognize PAMP
NKT cells
recognize CD1
invariant T cell receptor -> all of these cells have the same receptor
