The TEA 2/16 monoclonal antibody specifically recognizes CD109 which is also known as C3 and PZP-like alpha-2-macroglobulin domain-containing protein 7 (CPAMD7), Gov platelet alloantigens, or 150 kDa TGF-beta-1-binding protein. CD109 is a 150-170 kDa glycosylphosphatidylinositol (GPI)-linked glycoprotein expressed on activated T cells, myeloid progenitor (CD34+) and mature myeloid lineage cells (monocytes, granulocytes, platelets), but not on CD34+ lymphoid progenitor cells. CD109 is also expressed on vein and artery endothelial cells. The expression of CD109 is upregulated on PHA-stimulated T cells. CD109 is reportedly expressed on long-term adult bone marrow cultured cells, where it is co-expressed with CD34 and CD90. Its biological role in hematopoiesis has not been fully elucidated. It may play a role in the negative regulation of transforming growth factor beta receptor signaling.
The antibody was conjugated to BD Horizon™ BUV661 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 661-nm. BD Horizon Brilliant BUV661 can be excited by the ultraviolet laser (355 nm) and detected with a 670/25 filter and a 630 nm LP. Due to cross laser excitation of this dye, there may be significant spillover into channels detecting APC-like emissions (eg, 670/25-nm filter).
Due to spectral differences between labeled cells and beads, using BD™ CompBeads can result in incorrect spillover values when used with BD Horizon BUV661 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended. Different BUV661 reagents (eg, CD4 vs. CD45) can have slightly different fluorescence spillover therefore, it may also be necessary to use clone-specific compensation controls when using these reagents.