A SV-40 immortalized murine endothelial cell line from peripheral lymph node high endothelium expresses a new alpha-L-fucose binding protein.
Résumé
Endothelial cells from mouse peripheral lymph nodes were immortalized by cationic liposome-mediated transfection using a plasmid construct containing both the gene coding for the large T antigen of simian virus 40 and a geneticin resistance gene suitable for selection. A cell line (HECa10) was isolated on the basis of its capacity to specifically bind fucoside carrying glycoconjugates; these cells present the main characteristics of endothelial cells: production of angiotensin converting enzyme and of factor VIII-related antigen. Upon stimulation, they express E-selectin which binds oligosaccharides containing the Lewisx determinant (Fuc alpha 3[Gal beta 4 GlcNAc beta 3Gal beta) and the MECA 79 addressin which is characteristic for the peripheral lymph node high endothelium and is a L-selectin ligand. HECa10 cells, as well as peripheral lymph node high endothelial cells in primary culture, express a second fucoside binding protein which differs from E-selectin. Indeed, this new fucoside-binding protein is constitutively expressed on unstimulated cells while E-selectin is not. Furthermore, HECa10 cells mediate selective lymphoid cell adhesion in a selectin/addressin-dependent mechanism, mainly inhibited by MECA 79 antibody and, in a fucose-binding lectin-dependent manner, mainly inhibited by the specific neoglycoprotein.