Characterization of CD4 T Cell Epitopes of Infliximab and Rituximab Identified from Healthy Donors

Abstract

The chimeric antibodies anti-CD20 rituximab (Rtx) and anti-TNFα infliximab (Ifx) induce antidrug antibodies (ADAs) in many patients with inflammatory diseases. Because of the key role of CD4 T lymphocytes in the initiation of antibody responses, we localized the CD4 T cell epitopes of Rtx and Ifx. With the perspective to anticipate immunogenicity of therapeutic antibodies, identification of the CD4 T cell epitopes was performed using cells collected in healthy donors. Nine T cell epitopes were identified in the variable chains of both antibodies by deriving CD4 T cell lines raised against either Rtx or Ifx. The T cell epitopes often exhibited a good affinity for human leukocyte antigen (HLA)-DR molecules and were part of the peptides identified by MHC-associated peptide proteomics assay from HLA-DR molecules of dendritic cells (DCs) loaded with the antibodies. Two-third of the T cell epitopes identified from the healthy donors stimulated peripheral blood mononuclear cells from patients having developed ADAs against Rtx or Ifx and promoted the secretion of a diversity of cytokines. These data emphasize the predictive value of evaluating the T cell repertoire of healthy donors and the composition of peptides bound to HLA-DR of DCs to anticipate and prevent immunogenicity of therapeutic antibodies.

Silicone Oil Particles in Prefilled Syringes With Human Monoclonal Antibody, Representative of Real-World Drug Products, Did Not Increase Immunogenicity in In Vivo and In Vitro Model Systems

“…It is noted that the identical peptide component or T-cell epitope of a given antigen can elicit immunological responses both in donors and in their cells ex vivo. [30][31][32][33] This is consistent with our findings that the orthogonal model systems used here show qualitatively similar responses to given sets of mAb aggregates from previous work 18,24 and other positive-or negative-control samples tested here. Also, responses in PBMC assays are reflective of the relative clinical immunogenicity rates.…”

A single T cell epitope drives the neutralizing anti-drug antibody response to natalizumab in multiple sclerosis patients

“…The highly diverse anti-idiotypic response is consistent with the presence of multiple B cell epitopes recognized by naïve B cells and contrasts with the T cell response that is largely limited to a single epitope that we mapped to the FR2-CDR2 region of NZM light chain. This finding highlights the merit of the humanization technology in limiting the T cell immunogenicity of therapeutic antibodies, since chimeric antibodies were found to elicit T cell responses against multiple epitopes in the FRs and CDRs of both heavy and light chains 20 . As expected, the residual immunogenicity is primarily in the CDR regions 21 , but it is still limited by HLA restriction and processing by antigen-presenting cells.…”

Applying MAPPs Assays to Assess Drug Immunogenicity

“…A previous study by Hamze et al compared T cell epitope mapping data, MAPPs data, and HLA binding assay data (8). HLA-DR binders identified for the monoclonal antibodies rituximab and infliximab covered most of the variable antibody sequence, which did not allow for proper matching with T cell epitope data.…”