Pattern recognition receptor (PRR) which binds Gram-positive and Gram-negative bacteria (PubMed:10224290). Also plays a role in binding of unopsonized particles by alveolar macrophages (PubMed:10224290). Binds to the secretoglobin SCGB3A2 (By similarity). Homotrimer; disulfide-linked. Trimers may assemble in larger oligomers thus resulting in the creation of a large surface capable of interacting with very large ligands. Expressed in alveolar macrophages, macrophages of lymph node sinues, and Kupffer cells in liver (at protein level). N-glycosylated.