CXCR4 Antibody

CXCR4, a G-protein coupled receptor (GPCR) with seven transmembrane domains, is a CXC chemokine  receptor specific for stromal-derived-factor-1 (SDF-1 or CXCL12). CXCR4 was initially discovered as one of the co-receptors for HIV entry into CD4+ T cells (1). Blocking CXCR4 could be potentially used as novel therapeutics for HIV treatment.

CXCR4 signaling plays an important role in  the migration, proliferation and quiescence of hematopoietic stem cell  and their retention within the bone marrow, where it has high levels of SDF-1/CXCL12(2). It has been demonstrated that CXCR4 signaling mediates CD20 up-regulation on B cells (3).

CXCR4 is highly expressed in more than 23 types of cancer, including breast cancer, ovarian cancer, melanoma, and prostate cancer, while there is very less or no expression of CXCR4 in healthy tissues. CXCR4 expression in cancer cells has been reported to be associated with tumor survival, growth and metastasis in tissues with high levels of SDF-1/CXCL12, such as lungs, liver and bone marrow (4, 5).

CXCR4 has been shown to regulate neuronal migration, cell positioning and axon wiring (6, 7). CXCR4 mutant mice displayed aberrant neuronal distribution, which implicates the role in neuronal disorders such as epilepsy. CXCR4 is also involved in  WHIM syndrome (8). WHIM mutations in CXCR4 were recently found in patients with Waldenstrom's macroglobulinemia, and these mutations are correlated to clinical resistance to ibrutinib (9, 10).