VP16 is known to be important for starting the lytic, or reproductive, cycle upon infection of a cell. However, "it has been dogma that VP16 is not involved in reactivation from the dormant stage," Sawtell said.
But in this study, which used a mouse model, production of VP16 was a prerequisite for the virus's reactivation.
"Further," Sawtell explained, "latency in the nervous system is favored because VP16 is not transported efficiently to the nerve cell nucleus."
"There's evidence that it's not transported efficiently. VP16 is likely to be left behind, which promotes the establishment of latency," Sawtell said.
In essence, the herpes virus uses VP16 to balance the lytic and dormant stages of its life cycle.
In a second study, this one appearing recently in the online issue of Nature Immunology, a team of Canadian and U.S. researchers say they've discovered one way that the immune system activates itself to hunt down type 1 herpes.
The authors stated that the findings may one day have implications in the fight against HIV and even cancer, in addition to herpes.
The U.S. Centers for Disease Control and Prevention has more on genital herpes.
SOURCES: Nancy Sawtell, Ph.D., researcher, division of infectious diseases, Cincinnati Children's Hospital Medical Center; March 23, 2009, news release, University of Montreal, Canada; March 26, 2009, PLoS Pathogens
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