Epitope Screening Using Hydrogen/Deuterium Exchange Mass Spectrometry
(HDX-MS): An Optimized Workflow for Accelerated Evaluation of Lead
Monoclonal Antibodies
Abstract
Background: Epitope mapping is an increasingly important aspect of
biotherapeutic and vaccine development. Recent advances in therapeutic
antibody design and production has enabled candidate mAbs to be
identified at a rapidly increasing rate resulting in a significant
bottleneck in the characterization of ‘structural’ epitopes, that are
challenging to determine using existing high throughput epitope mapping
tools. Here, Hydrogen/Deuterium Exchange Mass Spectrometry (HDX-MS)
epitope screening workflow was introduced that is well suited for
accelerated characterization of epitopes with a common antigen. Main
methods and major results: The method is demonstrated on set of 6
candidate mAbs targeting Pertactin (PRN). Using this approach, five of
the six epitopes was unambiguously determined using two HDX mixing
timepoints in 24 hours total run time, corresponding to substantial
decrease in the instrument time required to map a single epitope using
conventional HDX workflows. Conclusion: An accelerated HDX-MS epitope
screening workflow was developed. The two-timepoint ‘screening’ workflow
mapped all six mAbs and generated high confidence epitopes for five of
the six mAbs assayed. The substantial improvement in the rate of data
collection can advance HDX-MS for higher throughput investigations
supporting the ability to evaluate a broader number of mAb candidates at
an earlier stage of vaccine development.