Gene-specific Ebola therapies protect non-human primates from lethal diseaseJanuary 13, 2006Scientists have developed a successful strategy for interfering with Ebola virus infection that protected 75 percent of nonhuman primates exposed to the lethal disease. This is the first successful antiviral intervention against filoviruses like Ebola in nonhuman primates. The findings could serve as the basis for a new approach to quickly develop virus-specific therapies for known, emerging, and genetically engineered pathogens. In today's online issue of the journal Public Library of Science Pathogens, a research team led by Sina Bavari and colleagues at the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) reports using novel "antisense" drugs to interrupt normal Ebola virus replication. The work was performed in collaboration with AVI BioPharma, a U.S. biotechnology firm. According to the study's authors, antisense drugs are useful against viral diseases because they are designed to enter cells and eliminate viruses by preventing their replication. The drugs, which act by blocking critical viral genetic sequences, may be more potent than anti-virals such as protease inhibitors, which seek to inhibit a protein needed for viral replication. Ebola virus causes hemorrhagic fever with case fatality rates as high as 80 percent in humans. The virus, which is infectious by aerosol (although more commonly spread through blood and bodily fluids of infected patients), is of concern both as a global health threat and a potential agent of biological warfare or terrorism. Currently there are no available vaccines or therapies. "One advantage of this strategy is that it directly targets the virus," said the paper's first author, Kelly L. Warfield. "With Ebola infection, the virus grows so fast that it overtakes the host immune system. What we did, essentially, was to hold off the viral replication long enough for the host to mount an immune response and clear the virus." Working with a class of compounds known as antisense phosphorodiamidate morpholino oligomers, or PMOs, the team first performed a series of studies to identify PMOs that demonstrated activity against Ebola virus. Next, three of the PMOs were tested in mice, both individually and in combination. The combination of all three was found to be the most effective therapeutic approach in mice, whether the PMOs were administered before or after Ebola infection. Combination therapy was also tested in guinea pigs, where it appeared to be most effective when administered after infection. To further evaluate the efficacy of the three-PMO combination, four rhesus monkeys were treated with the drug two days prior to Ebola virus exposure. Three of the four were protected from Ebola infection. "These results, while preliminary, are very encouraging," said Colonel George W. Korch, USAMRIID commander, "especially when you consider that Ebola virus has, to date, been fairly intractable to effective treatment. We look forward to additional findings of success using these PMOs." US Army Medical Research Institute of Infectious Diseases |
|||||||||||||||||||||
| Related Ebola Current Events and Ebola News Articles 1930s drug slows tumor growth Drugs sometimes have beneficial side effects. A glaucoma treatment causes luscious eyelashes. A blood pressure drug also aids those with a rare genetic disease. Exon-skipping drug prevents muscle wasting, maintains muscle function in dystrophin deficient mice An exon skipping PPMO has demonstrated dramatic effects in the prevention and treatment of severely affected, dystrophin and utrophin-deficient mice, preventing severe deterioration of the treated animals and extending their lifespan. Outfoxing pox: Developing a new class of vaccine candidates In the annals of medicine, Edward Jenner's 1796 vaccination of a young boy against smallpox, using fluid from cowpox blisters, remains a landmark case. In a new study, Kathryn Sykes, a researcher at Arizona State University's Biodesign Institute and her colleagues have taken a fresh look at cowpox. World will miss 2010 target to stem biodiversity loss, experts say The world will miss its agreed target to stem biodiversity loss by next year, according to experts convening in Cape Town for a landmark conference devoted to biodiversity science. Scientists block Ebola infection in cell-culture experiments Researchers at the University of Texas Medical Branch at Galveston have discovered two biochemical pathways that the Ebola virus relies on to infect cells. OHSU scientists partner with others to form center aimed at combating infectious diseases Oregon Health & Science University and the University of Washington, along with a number of partner institutions across the Northwest, have received federal funding to form a regional research center aimed at combating emerging or re-emerging infectious diseases that pose a serious threat to human health. Drug blocks 2 of world's deadliest emerging viruses Two highly lethal viruses that have emerged in recent outbreaks are susceptible to chloroquine, an established drug used to prevent and treat malaria, according to a new basic science study by researchers at Weill Cornell Medical College in the Journal of Virology. Penn Study Identifies How Ebola Virus Avoids the Immune System Researchers at the University of Pennsylvania School of Medicine have likely found one reason why the Ebola virus is such a powerful, deadly, and effective virus. Using a cell culture model for Ebola virus infection, they have discovered that the virus disables a cellular protein called tetherin that normally can block the spread of virus from cell to cell. Iowa State University researchers discover structure of key Ebola protein Research led by Iowa State University scientists has them a step closer to finding a way to counter the Ebola virus. UT Southwestern researchers develop new strategy for broad spectrum anti-viral drugs Bavituximab, an anti-viral drug developed by UT Southwestern Medical Center researchers, shows promise as a new strategy to fight viral diseases, including potential bioterrorism agents. More Ebola Current Events and Ebola News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||