U of S Researchers Develop New Vaccine Candidate Against Hepatitis C

Posted January 10, 2006


FOR IMMEDIATE RELEASE - Tuesday, January 10, 2006 2006-01-02-OTHER

U of S Researchers Develop New Vaccine Candidate Against Hepatitis C

Researchers at the University of Saskatchewan's Vaccine and Infectious
Disease Organization (VIDO) have developed a vaccine candidate for hepatitis
C, leading to hope in the fight against a disease for which no vaccines are
yet available.

VIDO is the first in Canada to show that this vaccination technique may be
effective against HCV. The study was published in this month's Journal of
General Virology.

The team, funded by the Canadian Institutes of Health Research (CIHR) and
the Canadian Network for Vaccines and Immunotherapeutics (CANVAC), produced
a vaccine candidate that decreased the amount of a carrier virus expressing
hepatitis C virus (HCV) protein in mice by 100,000 times compared to the
control.

"This technique uses the body's own cells, called dendritic cells, to
vaccinate against hepatitis C," said Dr. Bhagirath Singh, Scientific
Director of the CIHR Institute of Infection and Immunity.

Dendritic cells are key components of the immune system, activating and
shaping the immune response. "The vaccine reduced the amount of hepatitis C
protein in a highly significant manner," he said. "This offers a very
promising approach to prevent liver disease caused by the virus and to
ultimately eliminate it from the body."

About 20 per cent of people who contract HCV overcome the virus on their
own. For those who develop chronic hepatitis, the immune system cannot clear
the infection.

"In patients with chronic hepatitis C, there is evidence that the function
of their dendritic cells is altered," said Sylvia van den Hurk, senior VIDO
scientist and member of the research team that developed the vaccine
candidate.

"We thought that if we could 'teach' the dendritic cells how to properly
activate the immune response and deliver them back to the patient as a
vaccine, the patients would clear or at least control the infection."

HCV is the leading cause for liver transplants in the western world, and its
annual death toll is expected to triple in the next 10 years. Worldwide,
there are about five times more people infected by HCV than with the HIV
virus. Treatment of hepatitis C, which like HIV is spread by blood-to-blood
contact, is costly and ineffective in about half the patients.

Researchers working in this field have a tough job, says van den Hurk. "The
hepatitis C virus is always mutating. For example, one patient can be
infected with a strain that spawns sub-strains with different sequences.
They are all present at the same time, in the same patient."

The VIDO vaccine uses a viral protein that is common among different
strains, ensuring that the vaccine will be effective against them.

The researchers exposed dendritic cells in vitro to a HCV protein. The cells
were also exposed to a strong immune stimulator to increase the immune
response and then injected into mice as a vaccine. Because HCV does not
infect mice, mice were challenged with a carrier virus containing the
hepatitis C protein. The levels of HCV protein in immunized mice using this
model were five orders of magnitude lower than the control.

Co-authors on the study include Hong Yu, a post-doctoral fellow at VIDO and
recipient of a National Canadian Research Training Program in Hepatitis C
post-doctoral fellowship award, and VIDO director Lorne Babiuk. Hui Huang
and Jim Xiang are members of the Saskatchewan Cancer Agency.

VIDO is recognized by the scientific community as a world leader in RandD
and commercialization of vaccines and novel formulation and delivery systems
for livestock and human diseases. VIDO is a financially self-reliant,
non-profit organization owned by the U of Sand operates with substantial
support from the Government of Canada and the governments of Alberta and
Saskatchewan, as well as industry competitive grants.

The CIHR is the Government of Canada's agency for health research. CIHR's
mission is to create new scientific knowledge and to catalyze its
translation into improved health, more effective health services and
products, and a strengthened Canadian health care system. Composed of 13
institutes, CIHR provides leadership and support to close to 10,000 health
researchers and trainees across Canada.

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For more information:

Tess Laidlaw
Communications Officer, VIDO
University of Saskatchewan
(306) 966-1506
laidlaw@usask.ca
www.vido.org

Marie-France Poirier
CIHR Media Relations
(613) 941-4563
mediarelations@cihr-irsc.gc.ca
www.cihr-irsc.gc.ca