Table 1.

Important microbial ligands of Toll-like receptors

Receptor	Ligand	Pathogen
TLR1	Triacyl lipopeptides	Bacteria, mycobacteria
TLR2	Peptidoglycan	Gram-positive bacteria
	Lipoteichoic acid	Gram-positive bacteria
	Lipoprotein, lipopetides	Different pathogens
	Atypical lipopolysaccharide	Leptospira interrogans
	Glycoinositolphospholipids	Trypanozoma cruzii
	Zymosan	Fungi
TLR3	Double-stranded RNA	Viruses
TLR4	Lipopolysaccharide	Gram-negative bacteria
	Fusion protein	Respiratory syncytial virus
	Taxol	Plants
TLR5	Flagellin	Bacteria
TLR6	Diacyl lipopeptides	Mycoplasma
TLR7	Single-stranded RNA	Viruses
	Imidazoquinoline, Loxoribine, Bropirimine	Synthetic compounds
TLR8	Single-stranded RNA	Viruses
	Imidazoquinoline	Synthetic compounds
TLR9	CpG-DNA	Bacteria, viruses
	Hemozoin	Plasmodium falciparum
TLR10	Nd	Nd
TLR11	Nd	Uropathogenic E. coli
	Profilin-like molecule	Toxoplasma gondii

CpG, unmethylated cytosine-guanosine; nd, not determined; TLR, Toll-like receptor.