Journal Article

Expanding the MAPPs Assay to Accommodate MHC-II Pan Receptors for Improved Predictability of Potential T Cell Epitopes

Looney, Cary M., Siegel, Michel, Bray-French, Katharine, Marban-Doran, Céline, Steiner, Guido, Springer, Sebastian, Ducret, Axel, Hickling, Timothy P., Hartman, Katharina

2023

Overview

A critical step in the immunogenicity cascade is attributed to human leukocyte antigen (HLA) II presentation triggering T cell immune responses. The liquid chromatography–tandem mass spectrometry (LC-MS/MS)-based major histocompatibility complex (MHC) II-associated peptide proteomics (MAPPs) assay is implemented during preclinical risk assessments to identify biotherapeutic-derived T cell epitopes. Although studies indicate that HLA-DP and HLA-DQ alleles are linked to immunogenicity, most MAPPs studies are restricted to using HLA-DR as the dominant HLA II genotype due to the lack of well-characterized immunoprecipitating antibodies. Here, we address this issue by testing various commercially available clones of MHC-II pan (CR3/43, WR18, and Tü39), HLA-DP (B7/21), and HLA-DQ (SPV-L3 and 1a3) antibodies in the MAPPs assay, and characterizing identified peptides according to binding specificity. Our results reveal that HLA II receptor-precipitating reagents with similar reported specificities differ based on clonality and that MHC-II pan antibodies do not entirely exhibit pan-specific tendencies. Since no individual antibody clone is able to recover the complete HLA II peptide repertoire, we recommend a mixed strategy of clones L243, WR18, and SPV-L3 in a single immunoprecipitation step for more robust compound-specific peptide detection. Ultimately, our optimized MAPPs strategy improves the predictability and additional identification of T cell epitopes in immunogenicity risk assessments.

• Publisher: MDPI AG,MDPI
• Subject: Adalimumab / Algorithms / anti-drug antibody / Antibodies / Antigen presentation / Antigenic determinants / Antigens / B cells / Biological products / Biological Sciences / CD4 antigen / Cell activation / Dendritic cells / Epitopes / genotype / Genotypes / Helper cells / Histocompatibility antigen HLA / Histocompatibility antigens / HLA antigens / HLA histocompatibility antigens / HLA II receptors / Identification / Immune response (cell-mediated) / Immunogenicity / Immunoprecipitation / in silico analysis / International economic relations / Liquid chromatography / Lymphocytes / Lymphocytes T / Major histocompatibility complex / MAPPs assay / Mass spectrometry / Mass spectroscopy / MHC antibodies / Peptides / Plasma cells / precipitin tests / Proteomics / risk / Risk assessment / Scientific equipment and supplies industry / T cell receptors / T cells / T-lymphocytes / tandem mass spectrometry