Pattern recognition receptor (PRR) which binds Gram-positive and Gram-negative bacteria (PubMed:7867067). Also plays a role in binding of unopsonized particles by alveolar macrophages (By similarity). Binds to the secretoglobin SCGB3A2 (By similarity). Homotrimer; disulfide-linked (PubMed:7867067). Trimers may assemble in larger oligomers thus resulting in the creation of a large surface capable of interacting with very large ligands (PubMed:17405873). Expressed in subpopulations of macrophages in the spleen and the medullary cord of lymph nodes (at protein level). N-glycosylated.