title: Ephrin-B3 binds specifically to B lymphocytes in blood and induces migration.
abstract: Eph receptors and ephrin ligands have been shown to be differentially expressed on leucocytes. Here, we show that one member of the ephrin-B subfamily of ephrins, ephrin-B3, specifically binds to B lymphocytes in blood. No binding was observed to T lymphocytes or monocytes. The ephrin-B3 binding receptor on B lymphocytes is so far not identified, but our results here indicate that ephrin-B3 binds to a protein not belonging to the Eph receptor family. Recently, we have shown that ephrin-B3 binds to a sulphated cell surface receptor on HEK293T cells and that this binding can be blocked with heparin. Ephrin-B3 binding to B lymphocytes is partially affected by heparin, and a basic amino acid in the extracellular juxtamembrane region, Arg-188, is here shown to be involved in this binding. The functional consequence of ephrin-B3 binding to B lymphocytes is induced migration, in particular of the memory cells. To conclude, ephrin-B3 binds to B lymphocytes, most likely via a non-classical receptor, and induces migration of the memory B cell subpopulation.
authors: Department of Medical Genetics, Oslo University Hospital, Ullevaal, Oslo, Norway.
authors: H L
authors: HL
authors: Holen
authors: L
authors: L
authors: Zernichow
authors: K E
authors: KE
authors: Fjelland
authors: I M
authors: IM
authors: Evenroed
authors: H
authors: H
authors: Tveit
authors: H-C
authors: HC
authors: Aasheim
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology*; D002465:Cell Movement / Q000276:immunology*; D036389:Ephrin-B3 / Q000276:immunology*; D057809:HEK293 Cells; D006493:Heparin / Q000276:immunology; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology; D011956:Receptors, Cell Surface / Q000276:immunology
chemical_list: D036389:Ephrin-B3; D011956:Receptors, Cell Surface; D006493:Heparin