Natural Products with Toll-Like Receptor 4 Antagonist Activity

Table 1

Ligands and immune cells expressing Toll-Like Receptors. Mo, monocytes; MΦ, macrophages, DC, dendritic cells; MC, mast cells; B, B lymphocytes; T, T lymphocytes; NK, NK cells; HSPs, heat shock proteins; HMGB1, high mobility group box 1; mRNA, messenger RNA; ssRNA, single-stranded RNA.

TLR	Subcellular	Immune cell	PAMPs	DAMPs
	localization	expression
TLR1/TLR2	Plasma membrane	Mo, MΦ, DC, B	Triacylated lipoproteins; Peptidoglycan; Lipopolysaccharide
				TLR2/TLR6	Plasma membrane	Mo, MΦ, MC, B	Diacylated lipopeptides; Lipoteichoic acid; Zymosan	HSPs; HMGB1; Versican; Hyaluronan
				TLR3	Endosome	B, T, NK, DC	Double strand RNA	mRNA
TLR4	Plasma membrane/endosome	Mo, MΦ, DC, MC	Lipopolysaccharide; F protein of syncytial virus; Mannuronic acid polymers; Teichuronic acid; Flavolipin; Mannan; NS1 protein of dengue virus	HSPs; HMGB1; Hyaluronan; Biglycan; Fibronectin; Heparan sulphate; Tenascin C
TLR5	Plasma membrane	Mo, MΦ, DC	Flagellin
TLR7	Endosome	Mo, MΦ, DC, B	ssRNA	ssRNA
TLR8	Endosome	Mo, MΦ, DC, MC	ssRNA	ssRNA
TLR9	Endosome	Mo, MΦ, DC, B, T	CpG DNA	Chromatin IgG complex
TLR10/TLR2; TLR10	Plasma membrane/; endosome	Mo, DC, B	Gram-positive molecules; Influenza virus molecules