Negative regulation of Toll-like receptor-4 signaling through the binding of glycosylphosphatidylinositol-anchored glycoprotein, CD14, with the sialic acid-binding lectin, CD33.

ABSTRACT: When monocyte-derived immature dendritic cells (imDCs) were stimulated with LPS in the presence of anti-CD33/Siglec-3 mAb, the production of IL-12 and phosphorylation of NF-κB decreased significantly. The cell surface proteins of imDCs were chemically cross-linked, and CD33-linked proteins were analyzed by SDS-PAGE and immunoblotting. It was CD14 that was found to be cross-linked with CD33. A proximity ligation assay also indicated that CD33 was colocalized with CD14 on the cell surface of imDCs. Sialic acid-dependent binding of CD33 to CD14 was confirmed by a plate assay using recombinant CD33 and CD14. Three types of cells (HEK293T cells expressing the LPS receptor complex (Toll-like receptor (TLR) cells), and the LPS receptor complex plus either wild-type CD33 (TLR/CD33WT cells) or muta

SUBMITTER: Ishida A 

PROVIDER: S-EPMC4155695 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature