Consumables

CD303, also known as blood dendritic cell antigen 2 (BDCA-2), is a type II transmembrane glycoprotein that belongs to the C-type lectin superfamily. CD303 is the most specific marker for the human plasmacytoid dendritic cell (pDC) and is only expressed in humans. CD303 consists of a single extracellular carbohydrate recognition domain (CRD), a transmembrane region, and a short cytoplasmic domain without an obvious signaling motif. CD303 transmits intracellular signals through an associated transmembrane adapter, the FcεRγ , which recruits the protein tyrosine kinase Syk, inducing protein tyrosine phosphorylation and calcium mobilization. CD303 signaling inhibits type I IFN secretion, preventing immune surveillance. CD303 is also involved in other pDC functions such as the inhibition of soluble TNF-related apoptosis-inducing ligand (TRAIL) secretion, which mediates the killing of target cells that express the TRAIL receptor. Although CD303 is a key marker of pDC, the nature and identity of CD303 ligands are presently unknown.