| 背景 | Like CD304 (BDCA-4/Neuropilin-1), the CD303 (BDCA-2) antigen1-4 is a specific marker for CD11c–CD123+ plasmacytoid dendritic cells (PDCs) in blood1,3 and bone marrow5. Additionally, CD303 (BDCA-2) expression is strictly confined to PDCs in tissue, e.g., tonsils or lymph nodes3,5. CD303 (BDCA-2) is a novel type II transmembrane C-type lectin3.5. Unlike binding of antibodies to CD304 (BDCA-4), binding of antibodies to CD303 (BDCA-2) inhibits IFN type I production, which is induced in PDCs by, e.g., influenza virus, CpG oligonucleotides, or serum of systemic lupus erythematosus patients3,5,7. Remarkably, PDCs can take up ligand via CD303 (BDCA-2) and process and present ligand to T cells1,3. CD303 (BDCA-2)+ dendritic cells show a plasmacytoid morphology, express the pre-T cell receptor α-chain and are CD4+, CD45RA+, CD304 (BDCA-4/Neuropilin-1)+, CD141 (BDCA-3)dim, CD1c (BDCA-1)–, and CD2–. They lack expression of lineage markers (CD3, CD14, CD16, CD19, CD20, CD56) and express neither myeloid markers such as CD13 and CD33, nor Fc receptors such as CD32, CD64, or FcεRI1.Unlike CD304 (BDCA-4/Neuropilin-1), CD303 (BDCA-2) is not detectable on CD1a+ dendritic cells generated ex vivo from monocytes or hematopoietic precursor cells. |
