[en] The production of complex heterologous proteins (e.g. monoclonal antibodies, mAbs) in plants has several advantages animal based systems such as low cost, scalability and limited risk of contamination by human pathogens. mAbs are glycoproteins that require to be targeted to the plant secretory pathway in order to be properly folded and matured. They are ultimately delivered in the cell wall and are expected to be freely released in the extracellular space and the external medium, which would greatly simplify downstream processing. However, a significant part of plant produced and secreted mAbs remains bound to the cell wall, therefore hindering recovery. In this study, we evaluated the extra-cellular release of root-secreted proteins of wild-type plants and cell wall mutants of Arabidopsis thaliana. Recovered protein were either analyzed by SDS-PAGE for full proteome profiling or by gelatin zymography to reveal the activity of cell wall-bound proteases. The production, secretion and release of recombinant IgG will be eventually studied in transgenic hairy-roots generated from selected mutants.
