Anti–L-selectin oligonucleotide ligands recognize CD62L-positive leukocytes: Binding affinity and specificity of univalent and bivalent ligands
✍ Scribed by Steven Ringquist; David Parma
- Book ID
- 101242980
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 172 KB
- Volume
- 33
- Category
- Article
- ISSN
- 0196-4763
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✦ Synopsis
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 aptam-ers 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.