BDCA

BDCA stands for Blood Dendritic Cell Antigen, a nomenclature used to classify human circulating dendritic cell subsets by surface markers detected with antibodies in flow cytometry. The BDCA markers provide a framework for identifying major subsets of blood dendritic cells in combination with other lineage markers.

The best-established BDCA markers are BDCA-1 (CD1c), BDCA-2 (CD303), BDCA-3 (CD141), and BDCA-4 (CD304, also known as Neuropilin-1). BDCA-1 and BDCA-3 primarily mark myeloid dendritic cells, while BDCA-2 and BDCA-4 are associated with plasmacytoid dendritic cells, though expression can vary with activation and maturation. These markers are typically used alongside negative selection markers such as CD3, CD14, CD19, and CD56 to exclude T cells, monocytes, B cells, and NK cells.

In laboratory practice, BDCA markers are used for flow cytometric analysis and for sorting dendritic cell subsets for functional studies, cytokine production assays, or development of dendritic cell–based vaccines. They are particularly useful for studying the distribution and behavior of dendritic cell subsets in peripheral blood from healthy individuals and patients.

Limitations include variability in BDCA expression due to activation, disease states, or tissue localization; not all dendritic cells express BDCA markers, and tissue-resident dendritic cells may differ from circulating subsets. Thus, BDCA-based identification is most informative when used as part of a broader panel of markers and contextual clinical or experimental information.