Immunomodulatory activity of extracellular Hsp70 mediated via paired receptors Siglec-5 and Siglec-14.

ABSTRACT: The intracellular chaperone heat-shock protein 70 (Hsp70) can be secreted from cells, but its extracellular role is unclear, as the protein has been reported to both activate and suppress the innate immune response. Potential immunomodulatory receptors on myelomonocytic lineage cells that bind extracellular Hsp70 are not well defined. Siglecs are Ig-superfamily lectins on mammalian leukocytes that recognize sialic acid-bearing glycans and thereby modulate immune responses. Siglec-5 and Siglec-14, expressed on monocytes and neutrophils, share identical ligand-binding domains but have opposing signaling functions. Based on phylogenetic analyses of these receptors, we predicted that endogenous sialic acid-independent ligands should exist. An unbiased screen revealed Hsp70 as a ligand for Sigl

SUBMITTER: Fong JJ 

PROVIDER: S-EPMC4682649 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature