Passive immunization with antibodies shows promise to mitigate a prevalent type of enterotoxigenic Escherichia coli diarrhea in LMICs. A study aimed to look over the expression of a monoclonal anti-ETEC CfaE secretory IgA antibody in N. benthamiana plants to facilitate access to passive immunotherapy. Forms of mAb 68–81, SIgA1, and SIgA2 were generated in N. benthamiana by co-expressing the light chain and engineered heavy chains with J chain and secretory components. SDS-PAGE, size-exclusion chromatography, western blotting, and LC-MS peptide mapping were used to compare the assembly and antibody expression with CHO-derived antibodies. Rapid fluorescence/mass spectrometry and LC-ESI-MS were used to access N-linked glycosylation. In vitro susceptibility to gastric digestion was examined in an experimental setup. Antibody activity was compared for antigen binding, a Caco-2 cell-based ETEC adhesion assay, an ETEC hemagglutination inhibition assay, and a murine in vivo challenge experiment. In plants, the SIAgA1 assembly seemed to be more effective than SIAgA2. Aversion to degradation by simulated gastric fluid was seen in both sub-classes as compared to CHO-produced 68–61 SIgA1. The in vivo immunological activities of the plants expressed SIgAs were comparable, although they had more homogeneous N-glycosylation than CHO-derived SIgAs. Antibodies produced in a plant line engineered for mammalian-like N glycosylation did not demonstrate altered functionality in vitro.In the murine infection model, the plant-derived SIgA2 mAb protected against diarrhea. Although antibody production and purification need to be improved, anti-ETEC SIgA antibodies produced in a low-cost plant platform are functionally comparable to CHO antibodies, indicating that they can be considered for passive immunotherapy in LMICs.
Link:www.tandfonline.com/doi/full/10.1080/19490976.2020.1859813
