The 13E11 monoclonal antibody specifically binds to CC chemokine receptor-like 1 (CCRL1) that is also known as C-C chemokine receptor type 11 (C-C CKR-11), or ChemoCentryx chemokine receptor (CCX-CKR). CCRL1 is a seven-transmembrane glycoprotein receptor that is encoded by ACKR4 (Atypical chemokine receptor 4) which belongs to the atypical chemokine receptor subfamily within the chemokine receptor superfamily. CCRL1 is expressed on stromal cells of lymph nodes, dermal lymphatic endothelial cells, and thymic epithelial cells. CCRL1 binds to several "homeostatic" chemokines including CCL19 (ELC), CCL21 (SLC), CCL25 (TECK) and CXCL13 (BLC) that can otherwise bind to functional chemokine receptors like CCR7, CCR9 or CXCR5. CCRL1 can thus serve as a decoy receptor that allows cellular uptake and degradation of these chemokines in a G protein-independent manner. This receptor may shape chemokine gradients in tissues by scavenging chemokines and thereby regulate the chemotaxis of thymic precursor cells, various leucocytes, including lymphocytes and dendritic cells, and cancer cells. CCRL1 expression is upregulated on some breast and hepatic cancer cell lines. The 13E11 antibody reportedly has ligand-like activity that results in the cellular internalization of CCRL1. This antibody recognizes an epitope in the N-terminus of the first extracellular domain of CCRL1.
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).