The interdependence of machine learning and LC-MS approaches for an unbiased understanding of the cellular immunopeptidome

ABSTRACT Introduction The comprehensive collection of peptides presented by major histocompatibility complex (MHC) molecules on the cell surface is collectively known as the immunopeptidome. The analysis and interpretation of such data sets holds great promise for furthering our understanding of basic immunology and adaptive immune activation and regulation, and for direct rational discovery of T cell antigens and the design of T-cell-based therapeutics and vaccines. These applications are, however, challenged by the complex nature of immunopeptidome data. Areas covered Here, we describe the benefits and shortcomings of applying liquid chromatography-tandem mass spectrometry (MS) to obtain large-scale immunopeptidome data sets and illustrate how the accurate analysis and optimal interpretation of such data is reliant on the availability of refined and highly optimized machine learning approaches. Expert opinion Further, we demonstrate how the accuracy of immunoinformatics prediction methods within the field of MHC antigen presentation has benefited greatly from the availability of MS-immunopeptidomics data, and exemplify how optimal antigen discovery is best performed in a synergistic combination of MS experiments and such in silico models trained on large-scale immunopeptidomics data.