Clone REA391 recognizes the human CD307e antigen, a 106 kDa single-pass type I membrane protein also known as Fc receptor-like protein 5 (FcRL5) or immune receptor translocation-associated protein 2 (IRTA2). CD307e possesses a cytoplasmic tail with inhibitory ITIM phosphorylation signaling motifs and was found to inhibit B cell antigen receptor signaling by recruiting SHP1 to two ITIM motifs upon B cell antigen receptor co-stimulation, resulting in diminished calcium influx and protein tyrosine phosphorylation. Co-stimulation of CD307e and the B cell antigen receptor promotes proliferation and differentiation of naive B cells. CD307e is expressed on both mature B cells and plasma cells, and is induced by EBV proteins. It is overexpressed on malignant B cells of hairy cell leukemia, chronic lymphocytic leukemia, mantle cell lymphoma, and multiple myeloma patients. In addition, serum levels of soluble CD307e are elevated in patients with several types of B cell tumors.
Additional information: Clone REA391 displays negligible binding to Fc receptors.
FCRL5, BXMAS1, CD307, FCRH5, IRTA2, PRO820