A Monoclonal Antibody Produced in Glycoengineered Plants Potently Neutralizes Monkeypox Virus

Abstract

The 2022 global outbreaks of monkeypox virus (MPXV) and increased human-to-human transmission calls for the urgent development of countermeasures to protect people who cannot benefit from vaccination. Here, we describe the development of glycovariants of 7D11, a neutralizing monoclonal IgG antibody (mAb) directed against the L1 transmembrane protein of the related vaccinia virus, in a plant-based system as a potential therapeutic against the current MPVX outbreak. Our results indicated that 7D11 mAb quickly accumulates to high levels within a week after gene introduction to plants. Plant-produced 7D11 mAb assembled correctly into the tetrameric IgG structure and can be easily purified to homogeneity. 7D11 mAb exhibited a largely homogeneous N-glycosylation profile, with or without plant-specific xylose and fucose residues, depending on the expression host, namely wild-type or glycoengineered plants. Plant-made 7D11 retained specific binding to its antigen and displayed a strong neutralization activity against MPXV, as least as potent as the reported activity against vaccinia virus. Our study highlights the utility of anti-L1 mAbs as MPXV therapeutics, and the use of glycoengineered plants to develop mAb glycovariants for potentially enhancing the efficacy of mAbs to combat ever-emerging/re-emerging viral diseases.

Codon optimization regulates IgG3 and IgM expression and glycosylation in N. benthamiana

“…Agroinfiltration was used extensively over the last decade for the transient expression of recombinant proteins in N. benthamiana . This applies also to mAbs, especially to IgG1, with large variation in expression levels ( Shanmugaraj et al, 2020 ; Chen, 2022 ; Esqueda et al, 2023 ). Comparably moderate levels were obtained by transient expression of other Ab isotypes and subtypes, like IgM and IgG3 ( Loos et al, 2014 ; Kallolimath et al, 2020 ; Kallolimath et al, 2021 ; Sun et al, 2021 ; Kallolimath et al, 2023 ).…”