Coughing, sneezing, a stuffy head and fever may signal the onset of a cold, but these symptoms are really caused by the body fighting off the infection.
Now scientists at Johns Hopkins School of Medicine have found the switch that turns these reactions off ? it?s the same one that triggers the immune response.
“In cases when you can?t stop the system, we have found the immune system just goes out of control and you have an auto-immune response,” said Jun O. Liu, professor of pharmacology, neuroscience and oncology at Hopkins.
There are over 1 billion colds in the United States each year. Adults and children probably will have more colds than any other type of illness. Children average three to eight colds per year, and continue getting them throughout childhood. Parents often get them from their children. Colds are the most common reason that children miss school and parents miss work.
The key to curbing excess immune activity rests with carabin, a protein made by the specialized white blood cells that march in when a virus attacks. These cells begin producing carabin as soon as they go on the offensive against viral invaders, according to the article Liu published in the journal Nature this week. The more carabin present in the bloodstream, the more passive killer T-cells become.
Liu was not surprised by the findings. Many biological systems have a built-in inhibition, including cell growth and division. The malfunctioning or lack of these inhibitions leads to diseases ranging from cancer to auto-immune diseases like Lupus, where the immune system attacks healthy tissue.
If Carabin turns out, after further study, to be a keystone natural inhibitor of immune responses, Liu added, it may prove useful in stopping such unwanted immune reactions as the rejection of transplanted organs.
Currently there is no easy method to synthesize or extract the complex protein, Liu said. “This study is more interesting and significant from the perspective of our general understanding of the immune system.”
