Production of a monoclonal antibody in plants with a humanized N-glycosylation pattern

In recent years, plants have become an attractive alternative for the production of recombinant proteins. However, their inability to perform authentic mammalian N-glycosylation may cause limitations for the production of therapeutics. A major concern is the presence of beta1,2-xylose and core alpha1,3-fucose residues on complex N-linked glycans, as these N-glycan epitopes are immunogenic in mammals. In our attempts towards the humanization of plant N-glycans, we have generated an Arabidopsis thaliana knockout line that synthesizes complex N-glycans lacking immunogenic xylose and fucose epitopes. Here, we report the expression of a monoclonal antibody in these glycan-engineered plants that carry a homogeneous mammalian-like complex N-glycan pattern without beta1,2-xylose and core alpha1,3-fucose. Plant and Chinese hamster ovary (CHO)-derived immunoglobulins (IgGs) exhibited no differences in electrophoretic mobility and enzyme-linked immunosorbent specificity assays. Our results demonstrate the feasibility of a knockout strategy for N-glycan engineering of plants towards mammalian-like structures, thus providing a significant improvement in the use of plants as an expression platform.