Harnessing the Microbiome to Enhance Cancer Immunotherapy

Table 1

Human TLRs.

Toll-like receptor	Recognized PAMP/DAMP	Localization	Cellular expression	Therapeutic agonist
TLR3	dsRNA	Endosome	Myeloid DC, B cells; Intestinal epithelium	Poly(I:C)
TLR4	LPS, heat shock proteins fibronectin, uric acid; glycolipids, heparan sulfate	Plasma; membrane	MΦ, myeloid DCs,; mast cells; Intestinal epithelium	LPS, MPL
TLR5	Flagellin	Plasma; membrane	MΦ, subset DC; Epithelium, granulocytes	Flagellin
TLR7/8	ssRNA	Endosome	MΦ, plasmacytoid DCs mast cells,; B cells, myeloid DCs	Imiquimod; Resiquimod
TLR9	Unmethylated CpG-rich DNA	Endosome	MΦ, plasmacytoid DCs; B cells	Unmethylated CpG

Abbreviations: DAMP, damage-associated molecular pattern; DC, dendritic cell; dsRNA, double-stranded RNA; LPS, lipopolysaccharide; MPL, monophosphoryl lipid A; PAMP, pathogen-associated molecular pattern; Poly(I:C), polyinosinic:polycytidylic acid; ssRNA, single-stranded RNA; TLR, toll-like receptor.