i(3)so3-galactosylceramide and alpha-chymotrypsin

Sulphated galactocerebroside (sulphatide) has been established as a ligand for L-selectin and shown to trigger intracellular signals in human neutrophils. We have found that sulphatide activated transcription factor NF-kappa B in human neutrophils in a concentration-dependent manner whereas non-sulphated galactocerebroside did not demonstrate such an effect. The activation was inhibitable by pretreatment with primary monoclonal anti-L-selectin antibody (clone LAM1-116). Binding of the primary antibody to L-selectin was insufficient to induce NF-kappa B activation but cross-linking of L-selectin with a secondary antibody was effective. alpha-Chymotrypsin, the agent known to shed L-selectin, activated NF-kappa B by itself. The response to sulphatides was inhibited by jasplakinolide, an actin-polymerising agent known to downregulate surface expression of L-selectin, Fc gamma RIIIb, CD43 and CD44. Recently we have reported that sulphatide stimulated the attachment of human neutrophils to collagen via Mac1 (CD11b/CD18) integrin [Sud'ina et al., Biochem. J. 359 (2001) 621-629]. We now show signalling from sulphatide to NF-kappa B activation and discuss its involvement in neutrophil adhesion.

Topics: Antibodies, Monoclonal; Cell Adhesion; Chymotrypsin; Depsipeptides; Electrophoretic Mobility Shift Assay; Galactosylceramides; Humans; L-Selectin; Neutrophils; NF-kappa B; Peptides, Cyclic; Sulfoglycosphingolipids