How does the cold virus make us feel so miserable? Jack Elias, a pulmonary specialist at Yale, and his colleagues at the University of Virginia may be getting close to an answer. The researchers infected student volunteers with the virus and took fluid samples from their noses once a day. (They also took samples before infecting the students.) Fluid samples taken from the students after infection were found to be full of a protein called interleukin-6, or il-6, which is known to inflame respiratory tract cells; samples taken before the infection were free of the protein, says Elias. Working with cultures of respiratory tract cells, Elias’s team found that the gene that codes for il-6 is inactive unless a protein known as nf-kb (nuclear factor-kappa beta) attaches to the gene. But nf-kb is normally tied up by still another protein. The cold virus, the researchers found, somehow makes this latter protein release nf-kb, turning on the production of il-6, which may be the source of most cold symptoms. What we now have is a first hint of what the mechanisms are that allow the virus to trigger symptoms, Elias says. If you can control nf-kb, then you’ve got a whole new series of ways that you can treat--or maybe even prevent--the common cold.