Epitope-dependent mechanisms of CD27 neutralization revealed by X-ray crystallography. (March 2017)

• Record Type: Journal Article
• Authors: Obmolova, Galina; Teplyakov, Alexey; Malia, Thomas J.; Wunderler, Nicole; Kwok, Deborah; Barone, Linda; Sweet, Raymond; Ort, Tatiana; Scully, Michael; Gilliland, Gary L.
• Is Part Of: Molecular immunology. Volume 83(2017:Mar.)
• Page Start: 92
• Page End: 99
• Publication Date: 2017-03
• Subjects: ADCC antibody-dependent cell-mediated cytotoxicity -- CRD cysteine-rich domain -- ECD extracellular domain -- EDTA ethylenediaminetetraacetic acid -- ELISA enzyme-linked immunosorbent assay -- mAb monoclonal antibodiy -- HRP horseradish peroxidase -- PBS phosphate-buffered saline -- PDB Protein Data Bank -- PEG polyethyleneglycol -- PK pharmacokinetics -- SEC size exclusion chromatography -- SEM standard erro of mean -- SPR surface plasmon resonance -- TNF tumor necrosis factor -- RMSD root-mean-square deviation; CD27 -- Antibody -- Crystal structure -- Epitope -- Mechanism; Immunochemistry -- Periodicals; Molecular biology -- Periodicals; Immunochemistry -- Periodicals; Allergy and Immunology -- Periodicals; Molecular Biology -- Periodicals; Immunochimie -- Périodiques; Biologie moléculaire -- Périodiques; Immunochemistry; Molecular biology; Periodicals; Electronic journals; 571.96
• DOI: 10.1016/j.molimm.2017.01.005
• Languages: English
• ISSNs: 0161-5890

Abstract

Graphical abstract: Highlights: Two anti-CD27 antibodies exhibit distinctly different pharmacokinetics in monkeys. Crystal structure of CD27 with both mAbs reveals their non-overlapping epitopes. The different neutralization mechanisms of the two mAbs are linked to the epitopes. Abstract: CD27 is a T and B cell co-stimulatory protein of the TNF receptor superfamily dependent on the availability of the TNF-like ligand CD70. Two anti-CD27 neutralizing monoclonal antibodies were obtained from mouse hybridoma and subsequently humanized and optimized for binding the target. The two antibodies are similar in terms of their CD27-binding affinity and ability to block NF-κB signaling, however their clearance rates in monkeys are very different. The pharmacokinetics profiles could be epitope dependent. To identify the epitopes, we determined the crystal structure of the ternary complex between CD27 and the Fab fragments of these non-competing antibodies. The structure reveals the binding modes of the antibodies suggesting that their mechanisms of action are distinctly different and provides a possible explanation of the in vivo data.