We have recently described a monoclonal antibody (mAb) 4G4 recognizing a 70-kD molecule constitutively expressed on human endothelial cells and on subpopulations of lymphocytes. We showed that this molecule, which we named lymphocyte-vascular adhesion protein 2 (L-VAP-2), mediates lymphocyte adhesion to cultured endothelial cells. Protein sequencing of tryptic peptides from immunoaffinity-purified L-VAP-2 revealed sequence identity between L-VAP-2 and CD73 (ecto-5'-nucleotidase, E.C.3.1.3.5), and COS cells transfected with a CD73 cDNA were positively stained with the mAb 4G4, which recognizes L-VAP-2. mAb 4G4 was also able to partially inhibit the ecto-5'-nucleotidase activity of peripheral blood lymphocytes. Moreover, cross-precipitation studies performed with mAb 4G4 and a CD73 workshop mAb 1E9 showed that these two antibodies recognize the same molecule. Since the tissue distribution and biochemical characteristics of the two molecules are also similar, we conclude that L-VAP-2 and CD73 are the same glycoprotein. Adhesion experiments showed significantly increased binding of freshly isolated lymphocytes to COS cells transfected with a CD73 cDNA, as compared to mock-transfected COS cells, and binding of lymphocytes to CD73-expressing COS cells was inhibited by the presence of mAb 4G4 in the adhesion assay. CD73 is a glycosyl phosphatidylinositol-linked molecule previously shown to have a cosignalling role in T lymphocyte proliferation. Our data suggest that it also has a function in mediating lymphocyte adhesion to the endothelium.
Article|
November 01 1995
CD73 is involved in lymphocyte binding to the endothelium: characterization of lymphocyte-vascular adhesion protein 2 identifies it as CD73.
L Airas,
L Airas
National Public Health Institute, Turku University, Finland.
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J Hellman,
J Hellman
National Public Health Institute, Turku University, Finland.
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M Salmi,
M Salmi
National Public Health Institute, Turku University, Finland.
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P Bono,
P Bono
National Public Health Institute, Turku University, Finland.
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T Puurunen,
T Puurunen
National Public Health Institute, Turku University, Finland.
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D J Smith,
D J Smith
National Public Health Institute, Turku University, Finland.
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S Jalkanen
S Jalkanen
National Public Health Institute, Turku University, Finland.
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L Airas
National Public Health Institute, Turku University, Finland.
J Hellman
National Public Health Institute, Turku University, Finland.
M Salmi
National Public Health Institute, Turku University, Finland.
P Bono
National Public Health Institute, Turku University, Finland.
T Puurunen
National Public Health Institute, Turku University, Finland.
D J Smith
National Public Health Institute, Turku University, Finland.
S Jalkanen
National Public Health Institute, Turku University, Finland.
Online ISSN: 1540-9538
Print ISSN: 0022-1007
J Exp Med (1995) 182 (5): 1603–1608.
Citation
L Airas, J Hellman, M Salmi, P Bono, T Puurunen, D J Smith, S Jalkanen; CD73 is involved in lymphocyte binding to the endothelium: characterization of lymphocyte-vascular adhesion protein 2 identifies it as CD73.. J Exp Med 1 November 1995; 182 (5): 1603–1608. doi: https://doi.org/10.1084/jem.182.5.1603
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