Just as the cold season descends, scientists at The Johns Hopkins University are predicting a new wave of cheap, widely available medicines to stop sexually transmitted diseases, protect stomachs from gastrointestinal viruses and defend against the common cold.
Too good to be true? Not according to Hopkins scientists who have declared a revolution against a scourge of emerging infectious diseases. The arsenal, developed with new antibodies created in the lab, can be produced in common field crops, such as corn and soy, and provide protection against diarrheal diseases, respiratory ailments, and STDs.
The developments have enormous implications in the public health arena, the scientists say, because of the relatively recent identification of new battlefields for the fight -- mucosal surfaces, places such as the mouth, the vagina, and the nose, which are evolved by the body to interact safely with the external environment. Specifically, scientists are targeting the respiratory, gastrointestinal and genital/urinary tracts, where most pathogens are initially transmitted.
The scientists herald these new advances in biotechnology and provide an overview of burgeoning research with monoclonal antibodies (MABs) in the January-March issue of Emerging Infectious Diseases, a publication of the Centers for Disease Control.
"There's finally an understanding of how important mucosal surfaces are," said Kevin Whaley, a research scientist in biophysics and one of the authors of the report. "Immunology, of course, has been around forever and ever, but mucosal immunology is relatively new.
"Soon, we believe, with the use of monoclonal antibodies, a person could take a small tablet for traveler's diseases in the stomach, a squirt from an inhaler for respiratory protection, and, for general urinary tract infection, put a gel or controlled-release device in the vagina. New sexual lubricants could also be produced to block transmission of sexually transmitted diseases."
Although MABs are already entering the marketplace for therapeutic uses, Whaley and his colleagues argue that they could be far more effective on a global scale as preventatives through direct application on mucosal surfaces. MABs could serve in ways that vaccines do now, but more immediately and more directly.
"This represents a big shift in how the technology can be used," Whaley said. "A lot of the emerging infectious diseases are due to existing technology. Antibiotics, for example, are really part of the problem. We, as consumers, abuse antibiotics and doctors over-prescribe antibiotics, so every time we develop one of these new antibodies for therapeutic use, we force a pathogen into a unique strategy where it selects for resistant strains But if we start talking about prevention rather than therapy, we can get these antibodies directly to mucosal surfaces where they can prevent things from ever getting into the body and replicating."
More than 80 MABs are in clinical trials now. Just this month in Nature Biotechnology, Hopkins scientists reported the successful use of an antibody derived from soy that stopped the spread of genital herpes in mice.A scientist from London, Julian Ma, reported in the journal Nature Medicine that MABs made in tobacco had been used to prevent tooth decay in primates.
At the moment, MABs produced in cell cultures sell for $200 to $1,000 a gram. However, Whaley said, since scientists have discovered that MABs can also be derived from ordinary agricultural fields, it now seems likely that the so-called "plantibodies" could reasonably be produced by the boatload at a cost of less than $1 per gram.
Although it will take a few years to test the MABs in humans and conduct safety trials, Whaley and his colleagues predict that various applications will be commercially available before many ballyhooed new vaccines. Best of all, they believe they will be sold over-the-counter without prescription and, perhaps, become as common as toothpaste.
"Whenever you hear about some new emerging infectious disease, you also hear that someone's making a vaccine against it," Whaley said. "Then you wait and wait and wait. We've been hearing about vaccines for HIV and herpes and cancer for a very long time. You've got to think, "How long will we let that mythology keep going on"'
"From a public health viewpoint, there's not going to be a magic bullet, but there will become a variety of things people can do. For sexual health, it takes condoms, behavioral modification, microbicides and vaccines. It takes multiple layers of things to create public health. This is just one more opportunity to intervene."
Other authors of the report are Hopkins biophysicist Richard A. Cone and research scientist Larry Zeitlin of a biotechnical company called ReProtect. The three men are conducting research on monoclonal antibodies under a private initiative with ReProtect, which is operating under a research agreement with the university. Because ReProtect may, in the future, profit from commercial sales related to the research, the university manages its agreement with the company in accordance with its conflict of interest policies.
Emerging Infectious Diseases: http://www.
Nature Biotechnology report:
Richard Cone home page: http://www.jhu.edu/~biophys/Cone/cone.html