February 23, 2013
Scientists Develop New Drug Effective Against Drug-Resistant Influenza
Lee Rannals for redOrbit.com — Your Universe Online
Scientists writing in the journal Science say they have found a new class of influenza drug is effective against drug-resistant strains of the flu virus.
University of British Columbia (UBC) researchers published details about the development of a new drug candidate that is capable of preventing flu virus from spreading from one cell to the next. So far, the drug has tested successfully in mice trials, using lethal strains of the flu virus.
The flu virus utilizes a protein known as hemagglutinin to spread in the body, binding to the healthy cell's receptors. Once it has inserted its RNA and replicated, the virus then uses an enzyme, known as neuraminidase, to sever the connection and move on to the next healthy cell.
"Our drug agent uses the same approach as current flu treatments — by preventing neuraminidase from cutting its ties with the infected cell," senior author UBC Chemistry Prof. Steve Withers, said in a statement. "But our agent latches onto this enzyme like a broken key, stuck in a lock, rendering it useless."
According to the World Health Organization (WHO), the flu virus affects three to five million people around the world each year, causing 250,000 to 500,000 deaths.
"One of the major challenges of the current flu treatments is that new strains of the flu virus are becoming resistant, leaving us vulnerable to the next pandemic," said Withers, whose team includes researchers from Canada, the UK, and Australia.
"By taking advantage of the virus's own 'molecular machinery' to attach itself," Withers added. "The new drug could remain effective longer, since resistant virus strains cannot arise without destroying their own mechanism for infection."
Simon Fraser University virologist Masahiro Niikura and his doctoral student Nicole Bance reported in Science Express about how they discovered a new class of molecular compounds that can kill off the influenza virus as well. Their new compounds can lead to a new generation of anti-influenza drugs that the virus' strains are unable to adapt to. Ultimately, their drug could help buy scientists more time in developing new vaccines for emerging strains of the flu.
“Our new compounds are structurally more similar to sialic acid than Tamiflu," said Niikura, a Faculty of Health Sciences associate professor. "We expect this closer match will make it much more difficult for influenza to adapt to new drugs.”
Also, according to a recent redOrbit article, scientists say they found an important clue about how some people who are surrounded by infected people do not get the flu. This team wrote in Nature Immunology that some T-cells found on exposed body surface help to ward off infection better than others due to the selective expression of a certain protein known as IFITM3.
“If we learn how to increase the number and longevity of T-cells expressing IFITM3, this could lead to improved vaccines that promote the generation of more resistant T-cells able to provide the greatest protection, for longer,” study co-author Jose Villadangos, a biologist from the University of Melbourne, said in a statement.