September 12, 2005
Researcher identifies new way of combating viral diseases
Four seemingly unrelated viral diseases may some day be defeated by a single treatment, according to a recent collaborative study involving researchers at the University of Georgia's College of Veterinary Medicine.
Their study focuses on viruses responsible for HIV, measles, Ebola and Marburg and includes investigators from Vanderbilt University Medical Center and the Centers for Disease Control and Prevention. The study is being funded by a grant from the Hudson-Alpha Institute for Biotechnology.
In the September issue of the Journal of Virology, Thomas Hodge, research professor of infectious diseases at the veterinary college, and his colleagues report that blocking a protein that helps transport viruses out of a cell keeps these four viruses from reproducing and infecting other cells.
Most antiviral therapies target the virus itself, but viruses are quick to adapt to the body's attempts to disable them, Hodge explained. They can mutate rapidly and develop resistance to almost any antiviral compound. By focusing on the host cell while most scientists concentrate on the virus, Hodge and his colleagues hope to identify new ways to combat viral diseases.
The researchers identified a cellular protein called Rab9 "“ a factor required for viruses to reproduce in a cell. Disrupting Rab9 prevented the replication of four different viruses "“ Marburg, Ebola, HIV-1, and measles viruses.
"We believe that interfering with the Rab9 pathway interferes with the ability of the viruses to exit the cell, thereby dramatically decreasing the ability of the virus to spread rapidly and produce infection," Hodge said.
Because these viruses depend heavily on this exit pathway, they probably would not be able to find another route out of the cell. This suggests that Rab9 and other components of this exit pathway might be attractive targets for antiviral therapies for a variety of viruses.
Blocking Rab9 may have significant side effects, but there are people who live without Rab9, Hodge explained. Although they have metabolic problems, they are generally able to control their condition with diet and medication. Temporarily blocking the Rab9 pathway would be unlikely to harm the body, Hodge added, because human cells tend to have backup systems that can compensate.
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