We all heard the story of Jack and the giant bean stalk growing up and at one point thought “A cow for beans? What an idiot!” But perhaps Jack was just ahead of his time.
Our tale begins with the humble antibody…
Antibodies are the body’s way of seeking out intruders and illness in order to neutralize or destroy threats. They play a sort of good cop/bad cop role in our lives. Not only do they help the body combat disease (good cop), but they also play a significant role in auto-immune diseases (bad cop). Their presence can often be used to diagnose many diseases as well.
Antibodies can also be manufactured to identify almost anything. They are commonly used in labs to label cells and proteins, make things glow through immunofluorescence, or link up to facilitate chemical reactions.
The most stunning use of antibodies currently can be found in disease research and treatments. Antibodies are on their way out of the lab and are being used as therapeutic molecules for a whole host of diseases. Here is where Jack might have been on to something.
Plantibodies: the magical bean
Historically, antibodies have been made through injecting an antigen into an animal such as a rabbit. The rabbit would then naturally produce antibodies against that antigen. These antibodies could then be purified from the animals blood (this does not kill the animal) and used for disease treatment or research.
The first downside of this method is the upkeep of all the animals needed to produce large amounts of antibody. Also, since the animals used are closely related to humans, there is also the possibility of contamination. The animal might have an illness that the researchers are not aware of that could then be passed on through their blood. The highest precautions are taken to prevent this, but it is still a possibility.
But now, scientists are trading in the cow for the beans.
Plantibodies are human antibodies produced by genetically engineered plants. Unless you have a very strange family history, you are not closely related to any plants. This means that plants cannot pass on their diseases to people. They are also cheap to grow and can be raised in mass quantities.
How do they make these magical beans you might be thinking? Scientists are able to genetically engineer plants that have animal DNA included in their own. They then take the antibody of interest from the animal and inject it into the plants where it will be replicated through the plant’s own process of glycosylation. The antibodies can then be purified from the plants and used just like any other antibody.
Tobacco, understandably, has gotten a bad rap in the past few decades. Killing people is not very beneficial for anyone’s reputation. But that is all about to change. Tobacco has found a new PR manager in plantibodies.
The cost of producing antibodies in animals is high. Labs often pay thousands for small amounts. Because of this high production cost, treatable diseases like rabies are often a death sentence in developing countries. The low cost of plantibody production could change all of this.
Tobacco has been cultivated for centuries now. It is low cost, and can easily be grown in vast amounts. It can also be used to create antibodies. In fact, tobacco already has been used in labs to create antibodies (and potential treatments/cures) for Ebola, rabies, and West Nile.
We have just scratched the surface of what plantibodies can do. These plants are expected to yield over 10 kg of therapeutic protein per acre in tobacco, maize, soybean, and alfalfa plants. The cost of this production is expected to be only 1/1oth of the cost of production in animals.
Plantibodies can also be made from modifying seeds. Instead of injecting antibodies into a grown plant, they are instead placed inside seeds. When the seed later germinates, it has everything it needs to create plantibodies. This would allow for easy production and growth. These seeds can be stored for years and still be viable. If there is ever an epidemic, we could just break out the seeds and start growing. Seeds are also much easier to ship. They could be injected in a lab in the US, and then shipped to third world countries at little expense. Thus enabling them to grow their own therapies.
As mentioned before, plants cannot contract or spread human diseases. So there is no worry about production spreading diseases like HIV, prion diseases, or any other blood born pathogens.
Perhaps the most interesting application of plantibodies is the possibility of eating your treatment, no shot required. If antibodies could be produced in bananas or lettuce, you could treat or even prevent West Nile at meal times. No band-aids required.
So perhaps Jack wasn’t so foolish; he just wanted to cure the world. Though perhaps he should double check his science before planting the beans next time.
Drug discovery takes a long time and a lot of money. And most fail. Even if you have a miracle drug, it is takes a long time to get FDA approval.
Currently the biggest problem for plantibody production is that it falls under GMO regulations. And with so many states and groups pushing against these, plantibody production faces many problems. While most drugs only have to get approval from the FDA to be deemed safe, plantibodies are regulated by the FDA, EPA, and USDA.
While all of these regulations are put in place for public safety, perhaps it is time to revisit the regulation on plantibodies to make research a little easier. I personally would much rather eat a salad than get a shot any day.
Sadly, these plantibodies have not yet led to any magical giant bean stalks, but research is surely underway.