Researchers at the University of Wisconsin-Madison and Purdue University have discovered the atomic structure of an elusive cold virus associated with severe asthma and respiratory infections in children. Rhinovirus C, which is resistant to current antiviral drugs, is a major contributor to poor outcomes for individuals with chronic lung conditions and early exposure to the virus can cause lifelong lung scarring and lead to persistent respiratory problems, according to UW-Madison’s Ann Palmenberg, professor of biochemistry and with the Institute for Molecular Virology and co-author of the study.
By using a rhinovirus C preparation grown in the Palmenberg lab and an imaging technology new to Purdue, graduate student Yue Liu, first author of the study, was able to map the full atomic structure of a rhinovirus C particle. Discerning the structure of microscopic biological agents like viruses allows them to be studied and understood in ways not possible by other means, according to Science Daily. For example, Liu discovered the physical features of rhinovirus C that help explain why it is resistant to standard antiviral treatments and how it interacts with cells to cause infection.
Palmenberg says, “We found some interesting things. Unlike normal rhinoviruses, this one has spikes on the surface of the particles. We had not anticipated that.” This and other virus surface changes can help explain why clinical rhinovirus drug trials that rely on different virus surfaces have often failed when tested against rhinovirus C isolates over the last 4 to 5 years, according to Palmenberg. The spikes, however, present new binding sites for the human immune response to infection and may present promising new targets for the development of different drug types or they may contain structure elements that could be leveraged for effective vaccines.
The Science Daily report indicates that the results were unexpectedly quick and remarkable and with the new structure data, the team is much closer to finding answers. Mapping the rhinovirus C particles also showed where on these surfaces the virus likely makes contact with the CDHR3 molecules, which may present another opportunity to design drugs that may prevent infection. The virus was among the first samples analyzed with a new cryo-electron microscopy system at Purdue that allows for multiple imaging of single virus particles.
“Rhinovirus C has been the ‘missing link’ in explaining illness caused by the common cold,” says Michael Rossmann, Hanley Distinguished Professor of Biological Science at Purdue and co-lead of the study with Palmenberg. “This is sure to spark major new efforts toward the development of vaccines and antiviral drugs, particularly for the prevention of asthma.”
Photo Credit: Courtesy of the research team
Source: Science Daily