TY - JOUR
T1 - PV-1 is recognized by the PAL-E antibody and forms complexes with NRP-1
AU - Keuschnigg, Johannes
AU - Tvorogov, Denis
AU - Elima, Kati
AU - Salmi, Marko
AU - Alitalo, Kari
AU - Salminen, Tiina
AU - Jalkanen, Sirpa
PY - 2012/7/5
Y1 - 2012/7/5
N2 - 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.
AB - 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.
KW - Antibodies/immunology
KW - Antibody Specificity/immunology
KW - Carrier Proteins/immunology
KW - Endothelium, Lymphatic/immunology
KW - Endothelium, Vascular/immunology
KW - Fluorescent Antibody Technique
KW - Humans
KW - Membrane Proteins/immunology
KW - Neuropilin-1/immunology
U2 - 10.1182/blood-2012-01-406876
DO - 10.1182/blood-2012-01-406876
M3 - Article
C2 - 22627768
SN - 0006-4971
VL - 120
JO - Blood
JF - Blood
IS - 1
ER -