NEW YORK, Dec. 22, 2014 /PRNewswire-USNewswire/
-- Researchers at NYU Langone Medical Center and elsewhere say
that a vaccination they have developed to fight a brain-based,
wasting syndrome among deer and other animals may hold promise on
two additional fronts: Protecting U.S. livestock from contracting
the disease, and preventing similar brain infections in humans.
The study, to be published in Vaccine online Dec. 21, documents a scientific milestone: The
first successful vaccination of deer against chronic wasting
disease (CWD), a fatal brain disorder caused by unusual infectious
proteins known as prions. Prions propagate by converting otherwise
healthy proteins into a disease state.
Equally important, the researchers say, this study may hold
promise against human diseases suspected to be caused by prion
infections, such as Creutzfeldt-Jakob disease, kuru, familial
insomnia, and variably protease-sensitive prionopathy. Some studies
also have associated prion-like infections with Alzheimer's
disease.
"Now that we have found that preventing prion infection is
possible in animals, it's likely feasible in humans as well," says
senior study investigator and neurologist Thomas Wisniewski, MD, a professor at NYU
Langone.
CWD afflicts as much as 100 percent of North America's captive deer population, as
well as large numbers of other cervids that populate the plains and
forests of the Northern Hemishpere, including wild deer, elk,
caribou and moose. There is growing concern among scientists that
CWD could possibly spread to livestock in the same regions,
especially cattle, a major life stream for the U.S. economy, in
much the same manner that bovine spongiform encephalopathy, or Mad
Cow Disease, another prion-based infection, spread through the
United Kingdom almost two decades
ago.
According to Dr. Wisniewski and his research team, if further
vaccine experiments prove successful, a relatively small number of
animals (as few as 10 percent) could be inoculated to induce herd
immunity, in which disease transmission is essentially stopped in a
much larger group.
For the study, five deer were given the vaccine; another six
were given a placebo. All of the deer were exposed to
prion-infected brain tissue; they also were housed together,
engaging in group activities similar to those in the wild.
Scientists say this kept them in constant exposure to the
infectious prions. The animals receiving the vaccine were given
eight boosters over 11 months until key immune antibodies were
detectable in blood, saliva, and feces. The deer also were
monitored daily for signs of illness, and investigators performed
biopsies of the animals' tonsils and gut tissue every three months
to search for signs of CWD infection.
Within two years, all of the deer given the placebo developed
CWD. Four deer given the real vaccine took significantly longer to
develop infection -- and the fifth one continues to remain
infection free.
Wisniewski and his team made the vaccine using Salmonella
bacteria, which easily enters the gut, to mirror the most common
mode of natural infection -- ingestion of prion-contaminated food
or feces. To prepare the vaccine, the team inserted a prion-like
protein into the genome of an attenuated, or no longer dangerous,
Salmonella bacterium. This engineered the Salmonella to induce an
immune response in the gut, producing anti-prion antibodies.
"Although our anti-prion vaccine experiments have so far been
successful on mice and deer, we predict that the method and concept
could become a widespread technique for not only preventing, but
potentially treating many prion diseases," says lead study
investigator Fernando Goni, PhD, an
associate professor at NYU Langone.
Funding for the study was provided by the National Institutes of
Health grants NIH NS047433, ARRA NS047433-06S1 and the Seix Dow
Foundation.
In addition to Wisniewski and Goni, other NYU investigators involved in the study were
Kinlung Wong, BSc; Daniel Peyser,
MSc; and Jinfeng Zu, PhD. Research support was also provided by
Candace Mathiason, PhD; Jeanette Hayes-Klug; Amy
Nalls; Kelly Anderson; and
Edward Hoover, DVM, MS, of the
College of Colorado State University in
Fort Collins, where the deer were kept; Lucia Yim, PhD; Veronica
Estevez, MSc; and Jose A. Chabalgoity, PhD, at the
University of Uruguay in
Montevideo, where the vaccine was
developed; and David R. Brown, MD,
at the University of Bath in the United
Kingdom.
For more information, go to:
http://adc.med.nyu.edu/researchers/affiliated-labs/dr-thomas-wisniewski
www.elsevier.com/locate/vaccine
Media Contact:
David March
212 .404.3528│david.march@nyumc.org
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SOURCE NYU Langone Medical Center