title: PV-1 is recognized by the PAL-E antibody and forms complexes with NRP-1.
abstract: Pathologische anatomie leiden endothelium (PAL-E) antibody has been used for more than 20 years as a prototype marker for vascular endothelium. The elusive target of this antibody has been claimed to be plasmalemma vesicle-associated protein-1 (PV-1) and neuropilin-1 (NRP-1). Using immunofluorescence, we show that PAL-E, anti-PV-1, anti-NRP-1, and anti-CD31 antibodies show largely identical staining patterns in the vasculature of different tissues. However, PV-1-transfected cells only bind PAL-E and anti-PV-1 antibodies, whereas NRP-1 transfectants stain with anti-NRP-1 antibodies in flow cytometry. Using lysates from tissues and transfected cells, we further confirm that the molecule recognized by PAL-E and anti-PV-1 antibodies is not NRP-1 but PV-1. Nevertheless, coimmunoprecipitation studies unambiguously demonstrate that NRP-1 can form complexes with PV-1. This connects, for the first time, 2 molecules involved in leukocyte trafficking and angiogenesis, thereby opening interesting possibilities for future research in this field.
authors.affiliation: MediCity Research Laboratory, University of Turku, Turku, Finland.
authors.forename: Johannes
authors.initials: J
authors.lastname: Keuschnigg
authors.forename: Denis
authors.initials: D
authors.lastname: Tvorogov
authors.forename: Kati
authors.initials: K
authors.lastname: Elima
authors.forename: Marko
authors.initials: M
authors.lastname: Salmi
authors.forename: Kari
authors.initials: K
authors.lastname: Alitalo
authors.forename: Tiina
authors.initials: T
authors.lastname: Salminen
authors.forename: Sirpa
authors.initials: S
authors.lastname: Jalkanen
mesh_terms: D000906:Antibodies / Q000276:immunology*; D000918:Antibody Specificity / Q000276:immunology*; D002352:Carrier Proteins / Q000276:immunology* / Q000378:metabolism; D004729:Endothelium, Lymphatic / Q000276:immunology; D004730:Endothelium, Vascular / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D008565:Membrane Proteins / Q000276:immunology* / Q000378:metabolism; D039942:Neuropilin-1 / Q000276:immunology* / Q000378:metabolism
chemical_list: D000906:Antibodies; D002352:Carrier Proteins; D008565:Membrane Proteins; C486771:PLVAP protein, human; D039942:Neuropilin-1