Study: gene protects against flu and other viral diseases
The IFITM3 gene protects against flu and other viral diseases. This has now been found in a study published in the journal "Nature". If the gene is missing, a generally harmless flu develops into a life-threatening form in mice, similar to the Spanish flu. According to the study, patients who had to be hospitalized because of the H1N1 / 09 swine flu had defective versions of the IFITM3 gene.
Without the severe disease course of the flu IFITM3 sits on chromosome 11 and contains the genetic information for the "interferon induced transmembrane protein 3". The gene belongs to the interferon response to viral infections. In previous studies, a link between the IFITM3 gene and the defense against West Nile fever, influenza A and dengue was established. Aaron Everitt of the Wellcome Trust Sanger Institute in Hinxton near Cambridge and his team have now carried out systematic studies of the role of the gene for the first time. For this purpose, the IFITM3 gene was specifically switched off in knockout mice. The scientists were then able to observe severe disease courses in the animals. Mice, which usually had only mild flu, now showed strong symptoms of influenza. They also lost more than 25 percent of their weight.
IFITM3 gene is just one of many causes Usually mice eliminate the virus from their lungs within two days. The knockout mice with the IFITM3 gene switched off continued to struggle with their lives after a week, although the infection was also restricted to their lungs. Everitt's resulting conclusions state that the IFITM3 gene plays a crucial role in immune defense. To confirm this, the scientists examined 53 people who were hospitalized for severe swine flu in hospitals. In three of the patients examined, they discovered a mutation that leads to the production of truncated IFITM3 proteins. Such a mutation is usually much less common in only one in 400 people. Everett concludes that an altered IFITM3 gene is responsible for the severe course of the flu. However, since the mutation was only found in a few patients, it can be assumed that there are other causes. In the future, the scientists will have to look for further mutations in the interferon metabolism. The genetic analysis could eventually be used to diagnose increased susceptibility to viral diseases. Those affected could then be vaccinated accordingly. (ag)
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