The O323 monoclonal antibody specifically recognizes CD27 which is also known as Tumor necrosis factor receptor superfamily member 7 (TNFRSF7), T14, Tp55, or S152. CD27 exists as a ~110-120 kDa disulfide-linked homodimer comprised of two single-pass type I transmembrane glycoproteins that are encoded by CD27 (CD27 molecule). CD27 is expressed on medullary thymocytes and T cells, with higher expression on activated T cells, and subsets of mature B cells and natural killer (NK) cells. A soluble 28-32 kDa form of CD27 is produced by lymphocytes upon cellular activation. Binding of the CD27 antigen, expressed on T cells, to its ligand, CD70 (CD27L), provides a costimulatory signal, leading to T cell proliferation, production of cytotoxic T cells, and enhanced production of cytokines. Binding of CD70 to CD27 expressed on B cells leads to B cell proliferation and the generation of plasma cells and immunoglobulin production. The CD27 antigen becomes hyperphosphorylated on serine residues upon activation of T cells. Signaling through the CD27 antigen activates NFκB and stress activated protein kinase (SAPK)/c Jun N terminal kinase (JNK).
The antibody was conjugated to BD Horizon BB700, which is part of the BD Horizon Brilliant™ Blue family of dyes. It is a polymer-based tandem dye developed exclusively by BD Biosciences. With an excitation max of 485 nm and an emission max of 693 nm, BD Horizon BB700 can be excited by the 488 nm laser and detected in a standard PerCP-Cy™5.5 set (eg, 695/40-nm filter). This dye provides a much brighter alternative to PerCP-Cy5.5 with less cross laser excitation off the 405 nm and 355 nm lasers.