Zurich researchers have helped identify new molecules that are instrumental in the replication of the influenza virus – a development which they say makes a significant contribution towards finding new flu treatments.
Flu epidemics occur almost every year around the world, with some strains, such as H1N1 (swine flu) external linkin 2009-2010, causing global pandemics. In recent years it has been found that some influenza A viruses (IAV) are resistant to existing flu drugs, which can result in patients not responding to medication.
In Switzerland, seasonal flu accounts for up to 5,000 hospitalisations among vulnerable groups such as the elderly, and up to 1,500 deaths a year, according to the Federal Health Office.
Researchers know that influenza is triggered by infections with flu viruses which multiply heavily in the respiratory tract. For this, the viruses rely on host molecules. This has led to attempts to identify and block key host molecules to stop the virus replicating.
The international study, which involved the University of Zurich, also took this approach. Researchers - also from Germany and the United States - analysed datasets from independent publications on IAV host molecules. These studies focus on the totality of the genes and proteins required for the virus and generate a vast quantity of data.
They discovered 20 previously unknown host molecules that promote the growth of influenza A viruses, a statement from the University of Zurich said on Friday. The results are published in the journal Cell Host & Microbeexternal link.
“These unchangeable host proteins are vital for the replication of the viruses,” explained
Silke Stertzexternal link, a professor from the Institute of Medical Virology at the University of Zurich. “We can now use these to stop the virus from spreading further.”
20,000 new viruses from one cell
One of these host proteins is UBR4, which the virus needs to transport viral proteins to the cell membrane and construct new particles. This takes place as follows: the influenza A virus invades the host cell. The viral components are then carried to the cell surface, where they form new viruses. As a result, as many as 20,000 new influenza viruses can develop from one single infected host cell.
The study revealed that blocking UBR4 inhibits the production of new virus particles in infected cells. This “therefore provides evidence that blocking host molecules is feasible as a therapeutic strategy for the treatment of influenza,” the statement continued.
In addition, the research team has created a web-portalexternal link on influenza and host interaction which is available to other researchers.
“We expect the approach described in this study and the use of ‘big data’ to bridge the gap between biomedical research and therapeutic development, and facilitate fresh insights into previously unanswered medical questions,” said co-author Sumit Chanda from Sanford Burnham Prebys Medical Discovery Institute (SBP) in California.
swissinfo.ch and agencies