Innate Immunity II Flashcards
what occurs in the body if the chemical and physical barriers are successful in repelling a pathogen ?
pathogen encounter may not even be perceived by host
what occurs when pathogen expands at greater rate than immediate defenses can eliminate?
soluble chemicals and cellular receptors develop and inflammation operates to allow entry of innate cells from the blood and temp rises
what is PAMP?
pathogen associated molecular pattern, a conserved structure of a pathogen that is bound by an innate receptor
which cells have innate receptors?
- cellular barrier cells like epithelial cells, keratinocytes, or endothelial cells
- immune cells like macrophages, dendritic cells, lymphocytes
how do innate receptors trigger phagocytosis?
without signaling, except for signaling through toll-like receptors (TLR)
what are innate receptors known as?
pattern recognition receptors (PRR)
which is the only innate receptor/PRR that causes signaling to occur?
TLR (toll like receptors)
describe receptor mediated phagocytosis
- innate receptors bind microorganisms
- microorganisms are internalized by receptor mediated endocytosis
- endosome fuses with lysosome to form endolysosome where microorganisms are degraded
describe TLR
they are PRR with: extracellular domain for PAMP engagement that has leucine rich repeat region (LRR) AND cytoplasmic signaling domain Toll Interleukin 1 receptor TIR
what is the extracellular domain for TLR
leucine rich repeat region (LRR)
what is the cytoplasmic domain for TLR
toll interleukin 1 receptor (TIR)
what important TLR are located on the plasma membrane of innate cells?
- TLR4
2. TLR5
what important TLR are located in endosomes inside the cell?
- TLR3
- TLR7
- TLR9
which is TLR4 homodimer ‘s ligand?
lipopolysaccharide (LPS)
what microorganisms does TLR4 reconize?
gram negative bacteria
what cells express TLR4?
- macrophages
- dendritic cells
- mast cells
- eosinophils
where is TLR4 located?
plasma membrane
what is TLR7’s ligand?
single stranded viral RNAs
what microorganism does TLR7 recognize?
RNA viruses
what cells express TLR7?
- plasmacytoid dendritic cells
- NK cells
- eosinophils
- B cells
where is TLR7 located?
endosomes
what is TLR9’s ligand?
unmethylated CpG-rich DNA
what microorganism does TLR9 recognize?
- bacteria
2. DNA viruses
what cells express TLR9
- plasmacytoid dendritic cells
- B cells
- eosinophils
- basophils
where is TLR9 located?
endosome
what is TLR3’s ligand?
double stranded viral RNA
what microorganisms TLR3 recognize?
RNA viruses
what cells express TLR3?
NK cells
where are TLR3 located?
endosomes
what chromosome is TLR4?
9
what chromosome is TLR7?
X
what chromosome is TLR9?
3
what chromosome is TLR3?
4
