Modulation of Immunoregulatory Properties of Mesenchymal Stromal Cells by Toll-Like Receptors: Potential Applications on GVHD

Table 1

Recognition and signaling by Toll-like receptors.

PAMP	TLR	Transcription factors	Target genes
Triacyl lipopeptide	TLR1/2	NF-κB	Proinflammatory cytokines
Diacyl lipopeptide	TLR2/6	NF-κB	Proinflammatory cytokines
dsRNA	TLR3^#	IRF	Type I INF
LPS	TLR4	NF-κB and IRF	Proinflammatory cytokines and type I INF
Flagellin	TLR5	NF-κB	Proinflammatory cytokines
ssRNA	TLR7/8^#	NF-κB and IRF (pDCs)	Proinflammatory cytokines and type I INF (pDCs)
CpG-DNA	TLR9^#	NF-κB and IRF (pDCs)	Proinflammatory cytokines and type I INF (pDCs)

Notes. PAMPs derived from viruses, bacteria, and fungi are recognized by Toll-like receptors, in homodimers or heterodimers, resulting in the activation of transcription factors with subsequent transcription of target genes. Located in the plasma membrane. Located in intracellular compartments.