The 219133 monoclonal antibody specifically recognizes C-type lectin-like receptor 2 (CLEC-2). CLEC-2 is a ~32 kDa type II transmembrane glycoprotein that is encoded by CLEC1B (C-type lectin domain family 1 member B). CLEC-2 (CLEC1B) is expressed on platelets, megakaryocytes, and myeloid cells. The extracellular domain of this molecule contains a single carbohydrate recognition domain (CRD), whereas the cytoplasmic region contains a YXXL amino acid signaling motif which is also known as a hem-immunoreceptor tyrosine-based activation motif (hemITAM). Podoplanin binding to CLEC-2 (CLEC1B) leads to the transduction of tyrosine kinase signaling that can play roles in the activation and aggregation of platelets, tumor metastasis, or the formation of lymphatic vessels. CLEC-2 (CLEC1B) also serves as a receptor for the rhodocytin, a platelet-aggregating snake venom protein, or as a co-receptor for the attachment human immunodeficiency virus type 1 (HIV-1).
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.