The ability of rabbit alveolar macrophages to specifically recognize and adhere to surface derivatized with carbohydrates was examined. Otherwise inert polyacrylamide gels were derivatized with aminohexylglycosides as previously described (Guarnaccia, S.P., and Schnaar, R.L. (1982) J. Biol. Chem. 257, 14288-14292). Intact viable rabit alveolar macrophages, isolated by lung lavage, were placed in contact with surfaces derivatized with different glycosides. Only those surfaces derivatized with α-D-mannose residues were capable of supporting rabbit alveolar macrophage adhesion. Adhesion was rapid, obtaining maximal levels within 10 min, and occurred readily at either 0 or 37° C. The carbohydrate specificity of the cell adhesion was investigated by the use of soluble carbohydrate inhibitors. The potency of various saccharides to block the adhesion correlated with that demonstrated for blocking the uptake or binding of radiolabeled soluble glycoproteins (Shepherd, V.L., Lee, Y.C., Schlesinger, P.H., and Stahl, P.D. (1981) Proc. Natl. Acad. Sci. U.S.A. 78, 1019-1022). Thus, the order of potency observed was: D-Man ≃ L-Fuc > D-GlcNAc ≃ D-Glc >> D-Gal ≃ D-GalNAc ≃ L-rhamnose. While soluble monosaccharides were capable of blocking adhesion when added in millimolar concentrations, polymannosylated neoglycoproteins were able to block adhesion in the nanomolar concentration range. Adhesion to the mannose-derivatized surface was a dynamic event even at 0°C, since adhesion was less susceptible to monosaccharide inhibition at later incubation times. Surfaces derivatized with aminohexyl S-mannoside ligands were more effective in supporting adhesion than those derivatized with the corresponding O-mannosides. Soluble inhibitor studies suggest that this was due to a more favorable conformation of the S-glycoside for binding to the cell surface receptor. The results reported here demonstrate that the previously reported alveolar macrophage mannose/fucose receptor can mediate carbohydrate-specific cell adhesion.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Biological Chemistry|
|State||Published - 1984|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology