( Opening a new front in the war against ...)New drug blocks influenza, including bird flu virus

The new work, reported online this week (Oct. 4, 2006) in the Journal of Virology, describes the discovery of a peptide -- a small protein molecule -- that effectively blocks the influenza virus from attaching to and entering the cells of its host, thwarting its ability to replicate and infect more cells.

The new finding is important because it could make available a class of new antiviral drugs to prevent and treat influenza at a time when fear of a global pandemic is heightened and available antiviral drugs are losing their potency.

"This gives us another tool," says Stacey Schultz-Cherry, a UW-Madison professor of medical microbiology and immunology and the senior author of the new report. "We're quickly losing our antivirals."

The new drug, which was tested on cells in culture and in mice, conferred complete protection against infection and was highly effective in treating animals in the early stages of infection. Untreated infected animals typically died within a week. All of the infected animals treated with small doses of the drug at the onset of symptoms survived.

"Pretreatment with (the peptide) provided 100 percent protection against numerous subtypes (of flu), including the highly pathogenic H5N1 viruses...," according to the Journal of Virology report.

The new drug, known as "entry blocker," is a fragment of a larger human protein whose role in biology is to help things pass through membranes such as those that encapsulate cells.

Although the peptide's precise mechanism for thwarting flu remains to be deciphered, it seems to work by blocking the virus' ability to latch onto a key cell surface molecule that the virus uses to get inside cells. To survive and reproduc
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Source:University of Wisconsin-Madison