The HM48-1 monoclonal antibody specifically binds to CD48 (previously known as BCM1 in mice, Blast-1 in human, and OX-45 in the rat), a GPI-anchored member of the Ig superfamily. It is widely distributed on leukocytes, but not on non-hematopoietic cells, and its ligands include CD2 (LFA-2) and CD244 (2B4 antigen). The HM48-1 mAb blocks binding of soluble CD2 to CD48-bearing cells, blocks the interaction of CD2 and CD244, inhibits spleen cell proliferative responses to mitogens, augments the proliferative response of spleen cells when cross-linked with anti-CD3e mAbs, and inhibits priming of CTL in vitro. In vivo administration of HM48-1 antibody can prolong survival of cardiac allografts, an effect which is greatly enhanced by the addition of anti-CD2 mAb 12-15. This hamster mAb to a mouse leukocyte antigen does not cross-react with rat leukocytes.
The antibody was conjugated to BD Horizon™ BUV496 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.