A SV40 IMMORTALIZED MURINE ENDOTHELIAL-CELL LINE FROM PERIPHERAL LYMPH-NODE HIGH ENDOTHELIUM EXPRESSES A NEW ALPHA-L-FUCOSE BINDING-PROTEIN

Endothelial cells from mouse peripheral lymph nodes were immortalized by cationic liposome-mediated transfection using a plasmid construct c ontaining both the gene coding for the large T antigen of simian virus 40 and a geneticin resistance gene suitable for selection. A cell lin e (HECa10) was isolated on the basis of its capacity to specifically b ind fucoside carrying glycoconjugates; these cells present the main ch aracteristics of endothelial cells: production of angiotensin converti ng enzyme and of factor VIII-related antigen. Upon stimulation, they e xpress E-selectin which binds oligosaccharides containing the Lewis(x) determinant (Fuc alpha 3[Gal beta 4 GlcNAc beta 3Gal beta) and the ME CA 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, expre ss a second fucoside binding protein which differs from E-selectin. In deed, 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-depe ndent mechanism, mainly inhibited by MECA 79 antibody and, in a fucose -binding lectin-dependent manner, mainly inhibited by the specific neo glycoprotein.