CD303 (BDCA-2) antibodies have been used, for example, to identify, characterize, and enumerate plasmacytoid dendritic cells in whole blood of healthy and HIV-infected individuals, and for analyzing the role of DC-SIGN in HIV infection and transmission. Furthermore, CD303 (BDCA-2) antibodies have been used to identify and enumerate plasmacytoid dendritic cells in blood and bone marrow samples before and after hematopoietic stem cell mobilization or transplantation. CD303 (BDCA-2) antibodies have also been used for immunohistochemical staining, for example, to identify plasmacytoid dendritic cells in tissue sections from patients with different inflammatory skin diseases.
Clone REA693 recognizes the CD303 (BDCA-2) antigen which is expressed on human plasmacytoid dendritic cells in blood, lymphoid (e.g. tonsils and bone marrow), and non-lymphoid tissue. Specific expression allows direct identification of plasmacytoid dendritic cells using just one marker. CD303 (BDCA-2)+
plasmacytoid dendritic cells in blood and bone marrow are CD11c–
, CD304 (BDCA-4/Neuropilin-1)+
, CD141 (BDCA-3)low
, CD1c (BDCA-1)–
, and CD2–
. They express neither myeloid lineage markers (CD13, CD33) nor Fc receptors (CD32, CD64, FcRI). CD303 (BDCA-2) is strongly expressed on freshly isolated plasmacytoid dendritic cells but down-regulated within 48 hours of culturing. Unlike CD304 (BDCA-4/Neuropilin-1), CD303 (BDCA-2) is not detectable on ex vivo
generated monocyte-derived or hematopoietic precursor cell-derived CD1a+
The CD303 (BDCA-2) antigen is a novel type II transmembrane C-type lectin. Remarkably, plasmacytoid dendritic cells can take up ligands via CD303 (BDCA-2), then process and present the ligands to T cells. Unlike binding of antibodies to CD304 (BDCA-4), binding of antibodies to CD303 (BDCA-2) inhibits type I IFN production, which is induced in plasmacytoid dendritic cells by, for example, the influenza virus.
Additional information: Clone REA693 displays negligible binding to Fc receptors.