Streamlined molecular farming of plant virus therapeutics for space flight and other low-resource environments.

The resupply of pharmaceuticals during long-term space missions is challenging due to long travel distances and the reduced shelf-life of pharmaceuticals under extraterrestrial conditions. On-demand pharmaceutical production using plants could address this limitation. Plants are already cultivated in space, but the production of pharmaceuticals in plants is hampered by traditionally complex purification processes. Here, we describe a simplified production and purification strategy for cowpea mosaic virus (CPMV), a plant virus-based therapeutic candidate with strong immunomodulatory properties suitable for cancer therapy and vaccine development. By combining vacuum infiltration and centrifugation, intact CPMV particles were recovered from the apoplast without damaging the plant tissue, eliminating the need for tissue disruption. Impurities in apoplast eluates were efficiently removed by ultrafiltration/diafiltration, exploiting the size difference between CPMV and contaminants. The process was scalable when applied to more than 50 plants. We assessed the robustness of this production process under simulated space conditions, including microgravity, temperature shifts, and exposure to reactive oxygen species (ROS). Microgravity altered plant morphology, whereas temperature changes and ROS stress affected CPMV yields in a time-dependent manner. Beyond applications in space, these findings enable terrestrial strategies for plant molecular farming in low-resource environments.