Recombinant Human Dectin-1/CLEC7A Fc Chimera Protein, CF

Dectin-1, also known as CLEC7A and the beta -glucan receptor, is a type II transmembrane C-type lectin that participates in the innate immune response to fungal pathogens. Although Dectin-1 structurally resembles other CLEC molecules, it binds its ligands in a calcium-independent manner (1, 2). Mature human Dectin-1 consists of a short N-terminal ITAM-containing cytoplasmic tail, a transmembrane segment, and a C-terminal stalk with a carbohydrate recognition domain (CRD) in the extracellular domain (ECD) (3, 4). Alternate splicing generates one major isoform expressed on the surface of monocytes, macrophages, myeloid DC, neutrophils, eosinophils, B cells, and CD4+ T cells that lacks the stalk region (3-6). The mature ECD of human Dectin-1 shares 59% and 57% amino acid (aa) sequence identity with mouse and rat Dectin-1, respectively. The CRD of Dectin-1 selectively binds beta -glucan polymers, a major component of yeast and mycobacterial cell walls (5-7). Yeast beta -glucan is accessible to Dectin-1 only during the process of cell budding. Dectin-1 does not recognize the filamentous form of yeast (8). Dectin-1 mediates the phagocytosis of zymosan particles and intact yeast (8-10). In the membrane, Dectin-1 colocalizes with TLR2 in the presence of zymosan, and the two receptors cooperate in ligand recognition and the propagation of proinflammatory signaling (9, 11-13). Dectin-1 also interacts with tetraspanin CD37. This increases its stability on the cell membrane and inhibits ligand-induced signaling (14). Dectin-1 knockout mice show increased susceptibility to pathogenic infection (15, 16).