Professor Janet K. Yamamoto, PhD, from the Department of Infectious Diseases and Pathology, has been working on an HIV vaccine for 30 years, shown in the research lab at the Veterinary Academic Building at the University of Florida's College of Veterinary Medicine in Gainesville, Fla.
A Gainesville scientist has discovered that cats might provide promising clues for an HIV vaccine.
Janet Yamamoto, a petite and fiery professor of immunology at the University of Florida College of Veterinary Medicine who has spent the past 30 years studying feline immunodeficiency virus (FIV), has identified a common region in FIV and HIV: part of a protein on the virus that is critical to its survival and may be key to a vaccine.
“When I discovered FIV in 1986, it was a distant cousin to human HIV,” Yamamoto said, adding that “the protein sequence of the virus was similar between the two species.”
Now Yamamoto has found that a protein on the FIV virus triggered an immune response in blood from HIV-infected people. Her findings were published in the October issue of the Journal of Virology.
Stalled efforts in HIV vaccine
Yamamoto said efforts to develop HIV vaccines have not been very successful. In part, this is because they were based on antibodies (used successfully in flu vaccines) instead of T-cells — a type of white blood cell often compared to soldiers protecting the body’s immunity.
Yamamoto said she identified a region on FIV where T-cells were activated to produce more T-cells that killed HIV-infected cells only.
Importantly, that region also was unchanging, critical to finding a vaccine that will continue to protect people. “The fundamental issue is that the (HIV) virus changes rapidly” and has resisted previous vaccines, Yamamoto said.
“We needed to find areas on the virus that don’t change.”
Dr. Mobeen Rathore, director of the UF Center for HIV/AIDS Research, Education and Service in Jacksonville, also worked on the recent study.
“The virus is very smart. Every time we think we have a vaccine, the virus outsmarts us,” he said.
But this time, there’s a chance that the vaccine will work, he added.
The researchers now must continue to test their vaccine in cats.
“The good news is that cats will have a good second-generation vaccine,” Yamamoto said. “It’s good news for cat lovers.”
She discovered the first FIV vaccine in 2002.
In order to eventually be tested in humans, the vaccine must be tested in two animals, so monkey testing will follow, Yamamoto said. A similar protein region has been identified in SIV, or simian immunodeficiency virus, which infects monkeys.
“We could use those animals as a model,” Yamamoto explained. She added that despite the similarities in the virus among species, monkeys and cats cannot transmit the virus to humans.
At the same time, using the animal models to come up with a human vaccine is fairly intuitive and is not unlike the development of the smallpox vaccine from cow pox, Yamamoto said.
“I discover things by thinking simply,” Yamamoto said. “By thinking simply, you discover things.”
She added that researchers are at least five years away from studies in humans, provided the animal studies go well. She would like to get there, she said, by her retirement in seven years.
“I discovered FIV and the first cat vaccine,” she said. “Let me finish it up.”