MT4 (6B6) reacts with the 190, 205 and 220 kDa isoforms of the glycoprotein cell-surface antigen, CD45RB. The antigen is expressed primarily on a subset of human B and T lymphocytes, monocytes, macrophages and granulocytes (weak). CD4+, CD45RA- (memory T cells) cells show a differential expression of CD45RB. Bright CD45RB expression correlates with higher proliferation and IFNγ production when compared with dim CD45RB expression. CD45RB expression may be a mechanism for fine-tuning the responsiveness of memory cells in vivo.
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.