UK scientists think that they may have found a way to beat flu and possibly even SARS. Dr Tracy Hussell and colleagues at Imperial College London have found a way of controlling the way in which the immune system responds to flu. Research suggests that the immune system can react too strongly if we are infected with certain strains of flu, and that this immune react to infection can sometimes prove fatal. When flu infects the body it triggers the immune system into action and cells called T-cells begin to produce high levels of inflammatory molecules called cytokines. These cells are needed to help the body to destroy invading cells, however when levels get too high they can block the airways and prevent efficient transfer of oxygen into the bloodstream. Hussell found that blocking a molecule called OX40 prevents these immune system cells from clogging up airways. OX40’s job is to instruct activated T-cells to remain in the lungs for longer than normal in order to help fight infection, however when there is an excessive immune response there are so many cells entering the lungs that there is no need for the cells to hang around. Tests on mice infected with influenza A, the strain responsible for the 1919 flu pandemic that killed roughly 20 million people, revealed that blocking OX40 with an experimental drug called OX40:Ig effectively halted the excessive immune response and relieved the animals’ symptoms. Hussell says that the findings suggest that OX40:Ig could be used to treat any disease caused by an excessive T-cell inflammatory response, for example asthma, pneumonia, bronchitis, or possibly even SARS.
SOURCE/REFERENCE: Reported by www.bbc.co.uk on the 20th October 2003.
