The innate immune system is an ancient host defense mechanism found in almost every multicellular organism from plants to humans. In invertebrates it is the sole mechanism of defense against pathogens but in higher vertebrates constitutes the first line of defense.
|
Receptor |
Bacteria |
Viruses |
Fungi |
Parasites |
Small/Synthetic Molecules |
Endogenous Ligands |
|
TLR1
/
TLR2 |
Triacyl lipopeptides lipoarabinomannan
(LAM) from mycobacterium
|
|
Yeast/ Zymosan
|
Glycosylphosphatidyl inositol linked
proteins,
T. cruzi
|
|
|
|
TLR2
/
TLR2 (?) |
Published literature suggests the
existence of TLR2 homo-dimers, though specific ligands have yet to
be identified. |
|
TLR2
/
TLR6 |
diacyl
lipopeptides, LTA peptidoglycan
|
|
Yeast/ Zymosan
|
Glycosylphosphatidyl inositol linked
proteins,
T. cruzi
|
|
|
|
TLR3 |
|
dsRNA |
|
|
|
|
|
TLR4 |
LPS |
|
|
|
(Mouse TLR4),
Taxol |
Hsp60, Hsp70?, Hyaluronic Acid?
Heparan Sulfate? Fibrinogen?
|
|
TLR5 |
Flagellin |
|
|
|
|
|
|
TLR7 |
|
ssRNA |
|
|
Imidazoquinolines (Mouse TLR7),
Loxoribine
|
|
|
TLR8 |
ssRNA |
|
|
|
(Human TLR8) Imidazoquinolines |
|
|
TLR9 |
Bacterial CpG
|
Viral CpG |
|
|
|
|
|
TLR10 |
Unknown ligand(s) |
|
TLR11 |
(Mouse TLR11) Uropathogenic Bacteria
|
|
|
(Mouse TLR11)
T. gondii profilin,
apicomplexan profilins? |
|
|
|
TLR12 |
Unknown ligand(s) |
|
TLR13 |
Unknown ligand(s)
|