C-type lectin domain family 9 member A (CLEC9A)

CLEC9A is a **group V C-type lectin-like receptor** that appears as a type II transmembrane glycoprotein, expressed most highly and specifically on cDC1 (CD141^+^) dendritic cells in humans and CD8^+^ dendritic cells in mice[1][2][6]. Its extracellular domain contains a single C-type lectin-like domain lacking classical carbohydrate-binding residues, but containing conserved cysteine residues crucial for disulfide bond formation and dimerization[1][2]. CLEC9A functions as an **activation receptor** that mediates endocytosis (but not phagocytosis) of material from dead cells, and plays a critical role in the **cross-presentation** of antigens for activation of cytotoxic T lymphocytes (CD8^+^ T-cells)[2][5]. The intracellular tail contains an ITAM-like motif that recruits Syk kinase, leading to proinflammatory cytokine production. CLEC9A is a promising target in **immunotherapy and vaccine development**, offering selective delivery of antigens to a key dendritic cell subset for enhancement of immune responses against tumors and viruses[2][6].

Other names

CLEC9ACD370DNGR-1DNGR1C-type lectin domain containing 9AC-type lectin domain family 9 member AUNQ9341HEEE9341

Antigen delivery: Monoclonal antibodies targeting CLEC9A enable specific delivery of antigens to cDC1 dendritic cells, enhancing immune responses in the absence of additional adjuvants[6]. Immune activation: CLEC9A-mediated antigen presentation triggers proliferation of CD4^+^ and CD8^+^ T-cells[2][6].