Last year, Moderna quickly developed a candidate vaccine based on mRNA technology after the releasing of the Novel Coronavirus genome sequence by Chinese scientists. It made mRNA technology an overnight success. When immunized with mRNA vaccine, it acts as a blueprint for the immune system, meaning that the mRNA encodes the protein antigen, which is then produced by the host cell and induces an immune response that protects the body from the virus. However, the mRNA technology is not perfect, and one of the challenges is the requirement to maintain the stability of the cryogenic environment during vaccine transportation and storage.
Recently, scientists at the University of California, Riverside, San Diego, and Carnegie Mellon University were investigating whether eatable plants like lettuce could be turned into mRNA vaccine factories. If the new project is successful, it will mean that people can eat plant-based mRNA vaccines. This makes it possible to store vaccines at room temperature.
The goal of the project, funded by a $500,000 grant from the National Science Foundation, has three aspects: first, to demonstrate that DNA containing a vaccine mRNA could be successfully transplanted into plant cells and copied; The second is to prove that plants can produce enough mRNA; The third is to determine the correct dose.
“Ideally, one plant can produce enough mRNA to vaccinate a person,” said Juan Pablo Giraldo, assistant professor in the Department of Plant and Plant Sciences at THE University of California, Riverside, who led the study.
“We are testing this method with spinach and lettuce, and we have a long-term goal that one day people will be able to grow ‘vaccines’ in their homes,” Giraldo said. Eventually, farmers will be able to grow ‘vaccines’ on whole plots of land.”
The key to the work are chloroplasts, the tiny organs in plant cells that convert sunlight into energy the plant can use. “Chloroplasts are small solar factories that produce sugars and other molecules that make plants grow,” Giraldo said. They are also an untapped resource for making the molecules we need.”
In the past, Giraldo’s lab has shown that chloroplasts have the potential to express genes that are not natural components of plants. His team achieved this by delivering foreign genetic material into plant cells.
In the new project, Giraldo partnered with Nicole Steinmetz, a professor of nanoengineering at the University of California, San Diego, to deliver genetic material to chloroplasts using nanotechnology designed by her team.
“The idea is to reuse naturally occurring nanoparticles, plant viruses, to deliver genes to plants,” Steinmetz said. Some bioengineering studies are involved in this area, getting nanoparticles into chloroplasts and making them non-infectious to plants.”
“One of the reasons I work in nanotechnology is to be able to apply it to plants and create new technological solutions,” Giraldo said. Not just food, but also high-value products like medicine.”
Giraldo is also co-leading a related project that uses nanomaterials to deliver nitrogen (a fertilizer) directly to chloroplasts, where plants need it most.
Nitrogen is limited in the environment, but plants need it to grow. Most farmers apply nitrogen fertilizer to the soil, and as a result, about half of the nitrogen ends up in groundwater, polluting waterways and causing algal blooms and interactions with other organisms. It also produces another pollutant, nitrous oxide.
This alternative approach, which uses leaves to direct nitrogen into chloroplasts and control its release, is a more efficient application model that both helps farmers and improves the environment.
“I’m very excited about this study,” Giraldo said. I think it’s going to have a huge impact on people’s lives.”
