Extracellular lectin functioning as a pattern-recognition receptor in innate immunity. Binds the sugar moieties of pathogen-associated molecular patterns (PAMPs) displayed on microbes and activates the lectin pathway of the complement system. May also activate monocytes through a G protein-coupled receptor, FFAR2, inducing the secretion of interleukin-8/IL-8 . Binds preferentially to 9-O-acetylated 2-6-linked sialic acid derivatives and to various glycans containing sialic acid engaged in a 2-3 linkage.
Subcellular locations: Secreted, Cell membrane
Found on the monocyte and granulocyte surface .
Peripheral blood leukocytes, monocytes and granulocytes. Also detected in spleen, lung, and thymus, may be due to the presence of tissue macrophages or trapped blood in these tissues. Not detected on lymphocytes.