Pre-fractionation extends, but creates a bias in the detectable HLA class Ι ligandome

ABSTRACT: HLA class Ι molecules on the cell surface enable CD8+ T lymphocytes to recognize cellular alterations in the form of antigens, including mutations, protein copy number alterations, aberrant post-translational modifications or pathogen proteins. At any given moment, tens of thousands of different self and foreign HLA class Ι peptide ligands may be presented on the cell surface by MHC class Ι complexes. Analysis of the HLA ligandome thrusts therefore unique challenges due to their enormous biochemical diversity and inherently wide range of abundances. Despite advances in enrichment, separation, MS instrumentation and fragmentation, it is still not achievable to cover the HLA class Ι ligandome in sufficient depth to support routine identification of e.g. viral pathogens or immuno-therapeutically important tumor neo-antigens. In this study, we evaluate two pre-fractionation techniques, high pH reversed phase and strong cation exchange for complementary analysis of HLA class Ι peptide ligands, benchmarking them against analyses circumventing pre-fractionation. We observe that pre-fractionation substantially extends the detectable HLA class Ι ligandome, but also creates an identification bias. We advocate a rational choice between no-fractionation, high pH reversed phase or strong cation exchange pre-fractionation for deeper HLA class Ι ligandome analysis depending on the targeted HLA locus, allele or peptide ligand modification

INSTRUMENT(S): Orbitrap Fusion Lumos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): B Cell, Cell Suspension Culture

DISEASE(S): Disease Free

SUBMITTER: Laura Demmers  

LAB HEAD: W. Wu

PROVIDER: PXD011257 | Pride | 2019-02-25

REPOSITORIES: pride