Virus ‘barcodes’ rapidly identify mutated strains

Scientists use SILAC labelling and mass spectrometry to identify proteins

UK researchers are developing a way to 'barcode' viral diseases to test new outbreaks for potentially lethal mutations.

Dr Julian Hiscox and Dr John Barr of the University of Leeds's Faculty of Biological Sciences are working with the Health Protection Agency Porton (HPA) to build a bank of molecular signatures that will help identify the severity of virus infection from characteristic changes seen in cells. Currently the team is barcoding different strains of influenza virus and human respiratory syncytial virus (HRSV) – a virus associated with the onset of asthma in young children.

‘Diseases such as flu infect and hijack our cells, turning them into virus producing factories,’ says Hiscox. ‘The infection causes the balance of proteins in a cell to change – some proteins are overproduced and others suppressed. Which proteins are affected and by how much varies depending on the type of virus, allowing us to identify a unique barcode of disease for each.’

The research, published in Proteomics, investigates changes in lung cells infected with swine flu from the 2009 outbreak compared with seasonal flu. The team used a labelling technique called SILAC to measure and compare thousands of different proteins in a sample.

This technique was used alongside mass spectrometry to identify the proteins most affected by viral infection and used these as molecular signatures to provide the 'barcode' of disease.

The paper reports how the virus infected several processes in the cell, with most changes seen in proteins involved in cell replication.

‘Swine flu affects the lungs in a similar way to seasonal flu and this was reflected in the barcodes we found for each,’ explained Barr.

‘Using this test might have been a way to identify how lethal the 2009 swine flu pandemic was going to be, lessening worldwide panic.’

The next step will be to test more lethal strains of influenza, such as bird flu, to see how the barcodes differ.

The Leeds group has already barcoded two types of HRSV. Co-author Professor Miles Carroll of HPA Porton says this method could also be applied to a variety of viruses, including tropical diseases that are prone to sudden outbreaks and can be lethal.

The National Institute for Health Research (NIHR), the Biotechnology and Biological Sciences Research Council (BBSRC) and the Medical Research Council (MRC) provided funding for the research.

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