In the Bioprocess Engineering department at Fraunhofer IME, recombinant technical and therapeutic proteins have been produced in plants and plant cell cultures for 20 years. The recombinant technical and therapeutic proteins are produced in both stably transformed and transiently transformed cell lines.
The more than 100 different products include enzymes for the food and feed industry as well as growth factors, cytokines, monoclonal antibodies and proteinogenic vaccines for the pharmaceutical industry. In particular, the plant cell line Nicotiana tabacum BY-2 (BY-2) is used due to its high growth rate, comparable to mammalian cells, the high cell densities that can be achieved in bioreactors, and a high yield of the recombinant target protein. In addition, the BY-2 cell line does not contain secondary metabolites of concern such as alkaloids and human pathogens do not replicate in this organism, which simplifies the requirements for production under sterile conditions. Moreover, the department established suitable protocols to efficiently separate contaminants such as plant proteins (host cell proteins, HCP) and interfering secondary metabolites such as phenols from the target protein. Hence, the department can provide purified recombinant protein within six to eight weeks.