Imaging technology helps fight bad cold virus

Is your toddler suffering from bad cold again? It could be respiratory syncytial virus (RSV).

A new high-end imaging technology studying the structure of the RSV virion and its activity in living cells could help researchers unlock the secrets of the virus - how it enters cells, replicates, how many genomes it inserts into its hosts and perhaps why certain lung cells escape the infection relatively unscathed.

"We want to develop tools that would allow us to get at how the virus really works," said Philip Santangelo, associate professor at Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University.

"We really need to be able to follow the infection in a single living cell without affecting how the virus infects its hosts, and this technology should allow us to do that," he added.

Using direct stochastic optical reconstruction microscopy (dSTORM) imaging, they were able to characterise some aspects of the virus particle itself at super-resolution, down to 20 nanometers.

The research team, which included scientists from Vanderbilt University and Emory University, used a probe technology that quickly attaches to RNA within cells. The probe uses multiple fluorophores to indicate the presence of the viral RNA, allowing the researchers to see where it goes in host cells - and to watch as infectious particles leave the cells to spread the infection, said the study published in the journal ACS Nano.

"Being able to see the genome and the progeny RNA that comes from the genome with the probes we use really give us much more insight into the replication cycle. This gives us much more information about what the virus is really doing. If we can visualise the entry, assembly and replication of the virus, that would allow us to decide what to go after to fight the virus," Santangelo added.

For some children, especially premature babies and those with underlying health conditions, RSV can lead to pneumonia and bronchitis - which can require hospitalisation and have long-term consequences.

While RSV will be the first target for the work, the researchers believe the imaging technique they developed could be used to study other RNA viruses, including influenza and Ebola.

Among the mysteries that the researchers would like to tackle is why certain lung cells are severely infected - while others appear to escape ill effects.