EMERGE Episode 16: The potential of plasma HLA peptides beyond neoepitopes

Maria Wahle, a PhD student working in the lab of Matthias Mann at the Max-Planck-Institute of Biochemistry in Munich, presents her research on a new method for analysis of plasma HLA peptides using mass spectrometry. Soluble HLA (sHLA) peptides are thought to have great potential as biomarkers for different diseases such as cancer. However, efficient enrichment of sHLA peptides from body fluids like plasma has been a bottleneck, requiring 3-5 ml per patient. Maria presents IMBAS-MS, an automated magnetic bead based workflow for the efficient enrichment of HLA protein peptide complexes. The core of IMBAS-MS is the combination of biotinylated antibodies immobilized on streptavidin magnetic beads allowing for an automated one-pot enrichment from only 200 µl of plasma. In combination with Whisper low-flow gradients, data-independent acquisition (DIA), and computational library-based analysis we acquire deep immunopeptidomes from single measurements, elucidating its origins.