MHC-associated peptide proteomics (MAPPs) enables direct identification of peptides naturally processed and presented by APCs, providing experimental evidence for antigen processing and HLA class II presentation. In this dataset published in PMID: 41085630, an HLA-DR–focused MAPPs workflow was used on monocyte-derived dendritic cells (moDCs) from 8 donors loaded with infliximab, enabling characterization of the infliximab-derived HLA-DR T cell epitopes for this HLA donor cohort. Samples were measured using a 30 spd Evosep One LC method and MS analysis on a timsTOF-SCP in DDA-PASEF mode.