The UP-H1 monoclonal antibody recognizes Immune receptor expressed by myeloid cells 2 (IREM-2) which is also known as CD300 antigen like family member E (CD300e), CMRF35-like molecule 2 (CLM2), or Polymeric immunoglobulin receptor 2 (PIgR2). IREM-2 is a 34 kDa type I transmembrane glycoprotein which belongs to the CMFRF35 subfamily of the immunoglobulin (Ig) superfamily. IREM-2 is expressed on monocytes, macrophages and myeloid dendritic cells (mDCs), but not on lymphoid dendritic cells or granulocytes. IREM-2 associates with DAP-12, an ITAM-containing adapter molecule, which provides activating signals. Crosslinking of IREM-2 leads to intracellular calcium mobilization, release of proinflammatory cytokines such as TNF, and increased expression of activation markers on monocytes and mDCs. IREM-2 activation of mDCs can reportedly enhance the alloreactive response of naive T cells.
The antibody was conjugated to BD Horizon BUV615 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome with an Ex Max near 350 nm and an Em Max near 615 nm. BD Horizon Brilliant BUV615 can be excited by the ultraviolet laser (355 nm) and detected with a 610/20 filter and a 595 nm LP. Due to the excitation of the acceptor dye by the blue/yellow-green laser line, there may be significant spillover into channels detecting PE-CF594 like emissions (eg, 610/20-nm filter).