Plant-Based Systems for Producing Therapeutic Proteins: Current Status and Future Prospects.

Protein-based therapeutics have transformed modern disease treatment and now constitute a rapidly expanding segment of the pharmaceutical market. In this context, plant-based expression systems have emerged as a versatile alternative to conventional mammalian cell platforms for the production of recombinant proteins. Beyond their well-established advantages in cost, scalability, and biosafety, recent advances in transient expression technologies and plant cell culture systems have enabled rapid, high-yield production of complex biologics with increasing control over product quality. In particular, deconstructed viral vectors and Agrobacterium-mediated transient expression in plants enable rapid recombinant protein production, supporting their potential for applications requiring flexible and accelerated manufacturing. Concurrently, progress in host glycoengineering has enabled the generation of humanized and functionally tailored glycoforms, including antibody glycovariants with enhanced Fc-mediated effector functions. These advances have expanded the applicability of plant-based platforms to the production of monoclonal antibodies, antibody fragments, and emerging antibody-based modalities. In parallel, a broad range of single-chain therapeutic proteins, including enzymes, antimicrobial and antiviral agents, and proteins for inducing immune tolerance, have been successfully produced in plant systems as biologically active and functional therapeutics, demonstrating the broad utility of plant-based platforms across multiple therapeutic classes. This review provides a comprehensive overview of current plant-based production platforms, including whole-plant and plant cell suspension systems, and evaluates their comparative advantages and limitations relative to mammalian expression technologies. Recent progress in the development of therapeutic proteins, with an emphasis on monoclonal antibodies for passive immunization, is highlighted. Finally, the remaining technical, regulatory, and commercial challenges are discussed, along with future prospects for integrating plant-based systems into mainstream biopharmaceutical manufacturing.