Open AccessEngineering the interactions between a plant‐produced HIV antibody and human Fc receptors
Author(s) -
Stelter Szymon,
Paul Mathew J.,
Teh Audrey Y.H.,
Grandits Melanie,
Altmann Friedrich,
Vanier Jessica,
Bardor Muriel,
Castilho Alexandra,
Allen Rachel Louise,
Ma Julian KC.
Publication year - 2020
Publication title -
plant biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.525
H-Index - 115
eISSN - 1467-7652
pISSN - 1467-7644
DOI - 10.1111/pbi.13207
Subject(s) - glycosylation , monoclonal antibody , neonatal fc receptor , biology , receptor , glycan , antibody , fragment crystallizable region , nicotiana benthamiana , biochemistry , fc receptor , fucose , immunoglobulin g , microbiology and biotechnology , galactose , immunology , glycoprotein , gene
Summary Plants can provide a cost‐effective and scalable technology for production of therapeutic monoclonal antibodies, with the potential for precise engineering of glycosylation. Glycan structures in the antibody Fc region influence binding properties to Fc receptors, which opens opportunities for modulation of antibody effector functions. To test the impact of glycosylation in detail, on binding to human Fc receptors, different glycovariants of VRC 01, a broadly neutralizing HIV monoclonal antibody, were generated in Nicotiana benthamiana and characterized. These include glycovariants lacking plant characteristic α1,3‐fucose and β1,2‐xylose residues and glycans extended with terminal β1,4‐galactose. Surface plasmon resonance‐based assays were established for kinetic/affinity evaluation of antibody–FcγR interactions, and revealed that antibodies with typical plant glycosylation have a limited capacity to engage Fcγ RI , Fcγ RII a, Fcγ RII b and Fcγ RIII a; however, the binding characteristics can be restored and even improved with targeted glycoengineering. All plant‐made glycovariants had a slightly reduced affinity to the neonatal Fc receptor (FcRn) compared with HEK cell‐derived antibody. However, this was independent of plant glycosylation, but related to the oxidation status of two methionine residues in the Fc region. This points towards a need for process optimization to control oxidation levels and improve the quality of plant‐produced antibodies.