PROVIDENCE, R.I. -- For the first time, scientists have observed the herpes simplex virus traveling from the nerve ending to the nerve cell body within a living nerve cell, according to a team of researchers led by Elaine Bearer, M.D., at Brown University and the Marine Biological Laboratory at Woods Hole, Mass.
Herpes virus causes diseases ranging from the common cold sore to chicken pox. Genital herpes in women causes a significant risk of death for newborn babies.
Scientists have known that the herpes virus enters a mucous membrane, such as the lip, at the nerve ending and travels along the string-like nerve to the central nervous system near the brain, where the virus replicates or enters latency.
Until this study no one had observed and recorded that movement, said Bearer, associate professor in Brown's Department of Pathology and Laboratory Medicine. Understanding how a virus travels within the nerve cell may lead to better treatment and perhaps cures for potentially lethal viral infections.
"Our ability to directly observe the intracellular movements of the virus will enable us to discover the molecules and mechanisms by which herpes gets into the central nervous system," Bearer said.
To duplicate the movement from nerve ending to cell nucleus, Bearer and colleagues used a nerve cell from a Woods Hole squid as the model because the animal's "giant" axon -- 7 centimeters in length and 1 millimeter in diameter -- was largest enough to inject and provided good visibility.
The scientists stripped herpes simplex virus Type I of its envelope and injected the human virus into the squid axon. The study showed that the viral particles travel at an "enormously" fast and consistent speed of 2.2 microns per second, which indicates a single mechanism for movement, Bearer said.
"For a long time, it was believed that herpes traveled back to the central nervous system by infecting other cells in the nerve sheath," Bearer said. The virus does
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Contact: Janet Kerlin
Janet_Kerlin@brown.edu
401-863-2476
Brown University
2-Jul-2000