Common cold cure considered “possible”

Sneezing. Sniffling. Coughing. There’s not much you can do to stop the common cold except wait it out. But a new study published in Nature Microbiology may have lit the path to discovering a drug that can stop the virus in its tracks, scientists say.

Researchers in California recently discovered a protein needed for the viruses that cause the common cold to spread inside your body. Get rid of the protein, get rid of the virus.

That’s just what scientists at Stanford University and the University of California-San Francisco did, first in human cancer cells, then in lung cells and finally in live mice. The results of their study suggest a drug that can keep the virus away from that protein may be able to stave off your winter cold.

“There’s still a long road to go,” said Jan Carette, an associate professor of microbiology and immunology at Stanford University. “But I do think it’s an important step.”

A cure to the common cold has been elusive to scientists, in part because about 160 strains of rhinovirus can cause your sniffling, foggy head cold. To prevent the flu, by comparison, scientists target three to four strains of influenza each year. Scientists have been able to create vaccines that are fairly effective at targeting influenza, but going after 160 varieties of rhinovirus is much more difficult. Add to the puzzle the speed at which viruses mutate, and it’s easy to see why treating the common cold has long been a frustrating scientific enigma.

Scientists do know a few things about the spread of those rhinoviruses, which belong to a genus called enteroviruses. The virus penetrates a host cell and uses some of its own proteins and some of its host’s proteins to replicate, creating hundreds of copies of itself. Those copies spread to other healthy host cells and start the process again, until the immune system realizes the body is under attack and starts to fight the infection.

The California scientists searched for a way to inhibit the virus from spreading from cell to cell, which could lead to a new antiviral drug.

Carette started his hunt for a possible cure to the common cold by knocking out genes for possible “host proteins” one by one using CRISPR, a gene-editing technique that can alter specific DNA sequences from a cell or organism’s genome.

Carette’s team knocked out a different gene in thousands of cancer cells until they had systematically deleted each gene in the human genome. Each cell lacked one gene and one corresponding protein. Then, his team exposed the cells to two enteroviruses.

Some of the cells succumbed to the viruses, but others flourished.

The absence of one obscure protein consistently stopped the virus in its tracks: SETD3.

The researchers then turned off the gene for SETD3 in healthy human lung cells, which are often infected by rhinovirus strains. The virus failed to multiply and spread there.

Finally, Carette said, they used a live mouse to test whether an organism without the protein could avoid the virus.