Anti-L-selectin oligonucleotide ligands recognize CD62L-positive leukocytes: binding affinity and specificity of univalent and bivalent ligands

Cytometry. 1998 Dec 1;33(4):394-405. doi: 10.1002/(sici)1097-0320(19981201)33:4<394::aid-cyto2>3.0.co;2-0.

Abstract

Oligonucleotide aptamers generated against purified LS-Rg, a human L-selectin/IgG fusion protein, bound human CD62L-positive leukocytes. FACS analysis of lymphocytes or neutrophils stained with fluorescently labeled aptamers indicated specificity and sensitivity for cellular L-selectin similar to that observed with anti-L-selectin antibody. Univalent aptamers were compared to bivalent aptamers as well as to the anti-adhesion, anti-L-selectin antibody DREG56. Equilibrium and kinetic binding experiments were performed to examine the affinity and kinetic binding parameters of L-selectin aptamers to evaluate their binding to CD62L-positive leukocytes and to test their potential as L-selectin antagonists. Binding experiments indicated that bivalent aptamers approached the affinity and the dissociation rate of bivalent antibody, and preferentially recognized cellular compared to soluble L-selectin, a potentially useful distinction in vivo. Anti-L-selectin aptamers also inhibited L-selectin dependent self-adhesion of neutrophils suggesting that in vitro univalent and bivalent aptamers provided anti-adhesion activity similar to that observed with blocking antibody and indicated a direct blocking mechanism of action during inhibition of L-selectin-dependent trafficking of lymphocytes observed in vivo.

MeSH terms

  • Base Sequence
  • Cell Adhesion
  • Humans
  • Kinetics
  • L-Selectin / analysis*
  • L-Selectin / immunology
  • Leukocytes / immunology*
  • Ligands
  • Lymphocytes / immunology
  • Molecular Sequence Data
  • Neutrophils / immunology
  • Neutrophils / metabolism
  • Oligonucleotides / immunology*
  • Solubility
  • Staining and Labeling

Substances

  • Ligands
  • Oligonucleotides
  • L-Selectin