Picking up on over 20 years of research, the National Institute of Health is funding a project with the Health Sciences Center to develop an edible vaccine. The University is working in collaboration with Virginia Tech, TechLab, Inc., and CropTech and is supported by a $3.3 million, five-year grant from the NIH.
The purpose of the project is to research and create vegetables that prevent Entamoeba histolyca, a deadly parasitic infection.
"The goal is to take genetic information from the Entamoeba and express it" in the form of a vegetable, Biology Prof. Michael Timko said. Timko is being assisted by graduate and post-doctoral students using tobacco to modify the vaccination process.
Timko began working on the vaccine with Dr. Barbara Mann, an assistant professor in the Infectious Diseases area of the Medical School, working from a small grant from the Jeffress Memorial Trust.
"We expect to have a product ready to be tested in five years," Dr. Barbara Mann said. "At that point, we should be testing animals."
They have since joined Medicine-Infectious Diseases Prof. William Petri of the Medical School and incorporated their work with the larger NIH proposal.
"While amebiasis is primarily a disease affecting poor children in poor countries, if we can prove that an edible vaccine works for the disease, it opens the door to many diseases that we have in this country," Petri said.
Entamoeba histolyca is a parasitic ameba that causes amebiasis, and is estimated to be the third leading cause of death due to parasitic disease.
Amebiasis causes colitis, dysentery and liver abscess, and kills an estimated 100,000 people every year, according to the World Health Association.
In previous studies the University research team prevented amebic infection in animals by immunization with lectin, a sugar binding protein. By genetically engineering vegetables to express the amebic lectin, the Tropical Disease Research Unit is trying to create a special tomato or carrot.
The advantages of an edible vaccine are cost-efficiency, because there will be less need to send a doctor overseas and because an edible vaccine does not require refrigeration or sterile syringes.
The vaccine works by interrupting the process by which the parasitic ameba kills cells in the large intestine. In a matter of seconds, the ameba contacts a host cell and destroys it.
The human cells are not killed directly, but are tricked into committing suicide by the ameba in a process known as apoptosis. Lectin is the molecule that sticks the ameba to the human cell to initiate suicide.
In addition to the development of the vaccine, University investigators are working with children in a refugee camp in Bangladesh to better understand how the human immune system fights off this infection.
Mann remains optimistic about the vaccination process.
"This project has great potential," she said. "It's exciting to be able to do something to help the world."
Timko said he is also excited.
"It's a blending of plant biology and medical science," he said. "Expect to see more of it in the future."