To combat the common cold, scientists may need to devise one method to go after the rhinovirus C, right, a model of which UW-Madison researchers recently devised, and rhinovirus A, left, and B.

UW-Madison scientists haven’t cured the common cold, but they may have explained why nobody has — in a discovery that could lead to better drugs against sneezes and sniffles.

Campus researchers constructed a model of rhinovirus C, a particularly problematic strain of cold virus identified just seven years ago, and showed how it differs from rhinoviruses A and B.

Rhinoviruses cause about 85 percent of colds and account for some ear and sinus infections, bronchitis, pneumonia and asthma attacks.

Drugs against rhinoviruses haven’t done well in clinical trials. That is likely because they didn’t protect against rhinovirus C, according to the new study in Monday’s edition of the journal Virology.

“There was always a high failure rate,” said Ann Palmenberg, a UW-Madison biochemistry professor who led the research. “The drugs didn’t work against the Cs.”

The three-dimensional model Palmenberg’s lab designed of the protein shell of rhinovirus C could help scientists find a receptor that could be targeted by new drugs, she said.

Rhinovirus C viruses tend to cause severe colds, deep in the lungs, Palmenberg said. They are especially problematic in children, she said.

“The Cs are the bad nasties,” she said. “We have to devise two methods, one to go after the As and Bs, and one to go after the Cs.”

Palmenberg’s lab and a team from the University of Maryland were the first, in 2009, to sequence and analyze the genetic instructions for all 99 strains of rhinovirus known at the time.

The new study draws on that work and subsequent findings of 60 new strains of rhinovirus, most of them types of rhinovirus C.

Though rhinoviruses A and B have long been grown and studied in labs, it’s difficult to grow rhinovirus C, Palmenberg said. Gene chips can reveal their genetic sequences, however.

Palmenberg used the genetic sequences of about 500 rhinovirus C samples, many collected from UW Hospital asthma patients by Dr. Jim Gern, to develop the 3-D model.

The next step is identify the receptor unique to rhinovirus C. “If we can identify that new receptor, drugs that go after the receptor would go after the Cs,” Palmenberg said.


David Wahlberg is the health and medicine reporter for the Wisconsin State Journal.