When a pathogen attacks, your immune system mounts a two-stage response: an instant, generic one and a slower one tailored to the specific pathogen.
In the first response, cells release interferon—an alert to tissues around the body to produce up to 350 different proteins in the hope that they will halt the virus.
The scientists took advantage of a library of genes built up by American scientists, each of which encodes one of these 350 proteins. When a coronavirus was administered to cells, each of which contained one of these genes, they found that one molecule, LY6E, stood out as far more effective than the others at counteracting it.
They found the same for a number of coronaviruses they tested, including those that cause MERS, SARS (Severe Acute Respiratory Syndrome) and some that cause the common cold.
"I was very surprised to see such a strong effect," said Dr. Stephanie Pfänder, now at Ruhr Universität Bochum, Germany, who worked on the project.
What surprised them more was that, in a mouse model, the coronaviruses specially targeted the cells involved in the body's second, tailored immune response. If these immune cells don't swiftly produce LY6E, the coronavirus wipes them out, destroying the body's chance of launching the second wave of sustained defences against the disease.
"This is a very important molecule," said Prof. Thiel.
"If anybody in our population has a defect in that gene (which codes for it), they might be very vulnerable to infectious diseases." End quote
