Kevin Whaley, a research scientist at Johns Hopkins University, is one of a group of scientists developing new uses for monoclonal antibodies, "Monoclonal antibodis are a twenty year-old technology, so we have a lot of proof of concept for monoclonal antibodies. There are now over the last 2 to 3 years, six monoclonal antibody-based products approved by the FDA. We are now putting out our first products with monoclonal antibodies that we have produced against herpes, HSV2, and we also have produced a plantibody against sperm.."
Using natures own example, Whaley and his colleagues isolated cells from an infertile woman to create a spermicidal monoclonal antibody. The antibodies cause sperm to clump together so that the sperm cant get to the egg, thereby preventing pregnancy. The sperm are actually not killed, they bind to each other or are trapped in mucous in the vagina, which flows out over a twenty-four hour period.
Antibodies are our immune systems natural defense mechanism against invaders that are harmful, viruses and bacteria. Perhaps the most well known antibodies are those in mothers milk that are imparted to the infant as it suckles. While the infants immune system is not fully functional for the first months of life, the mother gives her baby the antibodies it needs to protect it from diahheria and pneumonia. Antibodies are very specific in targeting infectious invaders. Vaccines prepared from weakened or dead viruses stimulate the production of antibodies against that disease. Our immune system then remembers to release the antibody specific to that pathogen.
Monoclonal antibodies are a special set of antibodies that reproduce indefinitely from one kind of cell, making them easier for scientists to manufacture. Scientists can deliver these monoclonal antibodies into the blood stream directly, a much safer and accurate therapy than introducing dead viruses that the body reacts to, as in vaccines. The one problem remaining in monoclonal antibody technology, the cost of producing the antibodies in laboratories, is now a thing of the past thanks to plantibodies because crops can cheaply produce proteins in large quantities. According to Whaley, "Plantibodies because they are going to be very low cost but give us the same specificity and potency, they are going to allow us to make these consumer-based products. Antibodies primarily up to this point have been therapeutic and very costly. We now hope to move them into consumer-based products, and that1s what plantibodies allow us to do."
Our Mouths as Flower Beds
The first convincing evidence that plantibodies are an effective way to prevent pathogens from entering the body for long periods of time came from a London-based study this summer by Julian Ma and hiscolleagues at Guys Hospital. Ma grew a monoclonal antibody in tobacco plants, which was targeted to stop oral carries. Patients in the study were treated with a solution containing the antibody and remained protected against cavities for up to four months after the antibody had been washed out of the mouth. How could a simple mouthwash stop cavities for four months? The antibody had changed the ecology of the mouth. Bugs of many types compete for space in our mouths, "weeding" one type of bad bug allowed a new one to "grow" in its place.
Plantibodies Growing in the U.S.
Here in the U.S., plantibody production is already under way. In a Texas greenhouse, rows of corn are producing anti-sperm and anti-herpes antibodies. Spermicidal antibodies tested very well in a Johns Hopkins study in rabbits, and the implications of an anti-herpes monoclonal antibody for the sexual health of a U.S. population which has 1 million people infected with herpes each year is vast.
Plantibodies combine agricultural common sense with a set of antibodies scientists have been growing in petri dishes for the last 20 years. Scientists have confidence that a new wave of over-the-counter products will forever change public health, and provide a continuous stream of therapies to fight new diseases. Says Whaley, "Because we have rapid turn-around time, we can in 2 to 3 years be producing large quantities against any pathogen. As soon as an individual becomes infected we can take their cells, produce the monoclonal antibody, put them in plants, and provide them to the core population initially, and then to the broader populace in the next two to three years."
Elsewhere on the Web
Scientific American Article on Plantibodies in Corn
Centers for Disease Control and Prevention
American Social Health Association