Reduced Susceptibility of Recombinant Polyclonal Antibodies to Inhibitory Anti-Variable Domain Antibody Responses

Abstract

The immunogenicity of therapeutic Abs is a concern as anti-drug Abs may impact negatively on the pharmacodynamics and safety profile of Ab drugs. The factors governing induction of anti-drug Abs are not fully understood. In this study, we describe a model based on mouse-human chimeric Abs for the study of Ab immunogenicity in vivo. Six chimeric Abs containing human V regions and mouse C regions were generated from six human anti-Rhesus D Abs and the Ag-binding characteristics of the parental human Abs were retained. Analysis of the immune response toward the individual chimeric Abs revealed the induction of anti-variable domain Abs including anti-idiotypic Abs against some of these, thereby demonstrating the applicability of the model for studying anti-drug Ab responses in vivo. Immunization of BALB/c, C57, and outbred NMRI mice with a polyclonal composition consisting of all six chimeric Abs demonstrated that the immunogenicity of the individual Abs was haplotype dependent. Chimeric Abs, which were nonimmunogenic when administered individually, did not become immunogenic as part of the polyclonal composition, implying the absence of epitope spreading. Ex vivo Ab-binding studies established a clear correlation between the level of immunogenicity of the Abs comprised in the composition and the impact on the pharmacology of the Abs. These analyses demonstrate that under these conditions this polyclonal Ab composition was generally less susceptible to blocking Abs than the respective mAbs.

Immunogenicity of aggregates of recombinant human growth hormone in mouse models

“…In contrast, previous studies using interferon a2b transgenic mice showed that tolerance could be broken in response to administration of aggregated protein. 21 Important differences between the current study and the previous studies may be related to the natural function and abundance of the respective proteins, 5 as well as the mouse strains 60 used to generate the transgenic mice. The current study used the strain B6.SJL-Tg(HBB-GH1)420King/J, which results from the cross breeding of C57BL/6J with SJL strains, whereas the interferon a2b study was based on the strain FVB/N.…”

Immunogenicity of protein therapeutics

“…Although the use of the respective animal proteins might help elucidate basic immunological properties of the molecules studied, animal and human MHC are not equivalent because they can have different amino acid side-chain restrictions. This is best illustrated by the variability of immune response to chimeric antibodies in different strains of inbred mice [38]. For human homologs, standard animal models are even less predictive because the induction of immunogenicity in humans is based on breaking B and T cell tolerance, although such models do allow comparison of relative immunogenicity of different preparations of the same protein.…”

Characterization of Individual Human Antibodies That Bind Pertussis Toxin Stimulated by Acellular Immunization

“…Plasmablast cells were isolated by flow cytometry and sorted into single wells of 96-well plates (50 plates per donor), and the antibody-containing supernatants were screened by a custom Luminex assay for PTx reactivity (see Table S1 in the supplemental material). The antibody variable heavy chain (V H ) and variable light chain (V L ) sequences were then amplified from PTx-reactive wells by use of established methodologies ( 14 , 15 ), resulting in identification of five unique antibody sequences ( Fig. 1 ).…”