Peptides Derived from the Lectin Domain of Selectin Adhesion Molecules Inhibit Leukocyte Rolling In Vivo

Objective: The selectins are a family of adhesion molecules that mediate leukocyte rolling, a prerequisite for their later firm adhesion and migration to sites of inflammation. The N-terminal lectin domain of selectins is important for Ca²⁺-dependent binding to oligosaccharide ligands. We set out to study the effect of peptides corresponding to residues 11-20, 23-30, 36-50, 54-63, 70-79 and 109-118 (counting from the N-terminus of the mature proteins) of the lectin domain of human L-, P- and E-selectins on leukocyte rolling in vivo. Methods: Peptides were applied by local intravascular microinfusion via a glass micropipette into rat mesenteric venules. Visibly rolling cells were counted off-line and compared with rolling cells counted during control periods. Results: Peptides corresponding to residues 70-79 of P-selectin and 11-20 of L-selectin reduced leukocyte rolling flux in rat mesenteric venules to less than 30% of that measured during control infusion. Peptides corresponding to residues 109-118 of P-selectin, 54-63 of L-selectin and 23-30 of E-selectin also reduced leukocyte rolling flux, although to a lesser degree. Conclusions: We have shown that small peptides based on the lectin domain of all three selectins can be effective inhibitors of leukocyte rolling in vivo.