The 33D1 antibody recognizes Dendritic cell inhibitory receptor 2 (Dcir2) which is also known as, Dendritic Cells antigen, Dendritic Cell (DC) Marker, or 33D1 antigen. This antigen is expressed on most dendritic cells of spleen, lymph node, and Peyer's patch, but not liver, bone marrow, or epidermal dendritic cells; macrophages; other leukocytes; or erythroid cells. Within the spleen, the majority of 33D1+ DC are localized in the marginal zones. Thymic dendritic cells may express a low level of the 33D1 Antigen. It has been reported that bone-marrow DC can be induced to express the 33D1 antigen by culture in the presence of GM-CSF, and the resulting 33D1+ DC are effective in in vitro (induction of MLR) and in vivo (anti-tumoral vaccination) assays for antigen presentation. However, the addition of IL-4 to GM-CSF in bone-marrow cultures resulted in loss of 33D1 expression and enhanced the MLR-stimulatory activity of the DC. It has also been reported that 33D1 expression is upregulated when liver-derived DC are cultured on collagen-coated plates in the presence of GM-CSF. In vivo functional 33D1+ DC are induced in the brains of mice chronically infected with Toxoplasma gondii, probably via the parasite's induction of GM-CSF.
The antibody was conjugated to BD Horizon BB515 which is part of the BD Horizon Brilliant™ Blue family of dyes. With an Ex Max near 490 nm and an Em Max near 515 nm, BD Horizon BB515 can be excited by the blue laser (488 nm) laser and detected with a 530/30 nm filter. This dye has been exclusively developed by BD Biosciences and is up to seven times brighter than FITC with less spillover into the PE channel. Due to similar excitation and emission properties, BB515, FITC, and Alexa Fluor® 488 cannot be used simultaneously. It is not recommended to use BB515 in cocktails that include Streptavidin conjugates as it may cause high background.