Hydrogen/deuterium exchange mass spectrometry and computational modeling reveal a discontinuous epitope of an antibody/TL1A Interaction

MAbs. 2018 Jan;10(1):95-103. doi: 10.1080/19420862.2017.1393595. Epub 2017 Nov 14.

Abstract

TL1A, a tumor necrosis factor-like cytokine, is a ligand for the death domain receptor DR3. TL1A, upon binding to DR3, can stimulate lymphocytes and trigger secretion of proinflammatory cytokines. Therefore, blockade of TL1A/DR3 interaction may be a potential therapeutic strategy for autoimmune and inflammatory diseases. Recently, the anti-TL1A monoclonal antibody 1 (mAb1) with a strong potency in blocking the TL1A/DR3 interaction was identified. Here, we report on the use of hydrogen/deuterium exchange mass spectrometry (HDX-MS) to obtain molecular-level details of mAb1's binding epitope on TL1A. HDX coupled with electron-transfer dissociation MS provided residue-level epitope information. The HDX dataset, in combination with solvent accessible surface area (SASA) analysis and computational modeling, revealed a discontinuous epitope within the predicted interaction interface of TL1A and DR3. The epitope regions span a distance within the approximate size of the variable domains of mAb1's heavy and light chains, indicating it uses a unique mechanism of action to block the TL1A/DR3 interaction.

Keywords: HDX-MS; TL1A; computational modeling; electron-transfer dissociation; epitope mapping; hydrogen deuterium exchange.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / chemistry
  • Antibodies, Monoclonal / immunology
  • Antibodies, Monoclonal / metabolism*
  • Binding Sites, Antibody
  • CHO Cells
  • Cricetulus
  • Deuterium Exchange Measurement / methods*
  • Epitope Mapping / methods*
  • Epitopes / immunology*
  • Humans
  • Kinetics
  • Mass Spectrometry / methods*
  • Molecular Docking Simulation*
  • Protein Binding
  • Protein Conformation
  • Protein Interaction Domains and Motifs
  • Receptors, Tumor Necrosis Factor, Member 25 / immunology
  • Receptors, Tumor Necrosis Factor, Member 25 / metabolism
  • Tumor Necrosis Factor Ligand Superfamily Member 15 / chemistry
  • Tumor Necrosis Factor Ligand Superfamily Member 15 / immunology
  • Tumor Necrosis Factor Ligand Superfamily Member 15 / metabolism*

Substances

  • Antibodies, Monoclonal
  • Epitopes
  • Receptors, Tumor Necrosis Factor, Member 25
  • TNFRSF25 protein, human
  • TNFSF15 protein, human
  • Tumor Necrosis Factor Ligand Superfamily Member 15