Swiss TB Award for Mireia Coscollá Devís

There is a continuous “arm’s race” between immune systems and pathogens. The immune system develops antibodies against invading germs such as bacteria, viruses or parasites. These, in turn, answer with antigenic variation, i.e. they change their traits to undergo immune response. Most of the pathogens profit from this basic mechanism in infection biology.

However, the Mycobacterium tuberculosis, the pathogen causing tuberculosis in humans, diverges from this pattern. In collaboration with the New York University, Mireia Coscolla and her team led by Sébastien Gagneux could show that the antigens of the TB bacteria recognised by the immune system exhibit similar traits between different strains and are hyperconserved. This possibly created an evolutionary advantage for the TB-bacteria. For, during a TB-infection, these highly conserved antigens provoke a severe immune response that enables the bacteria to enter the lungs from where they are easily transmitted from humans to humans by coughing. “The almost lack of antigenic variation is the result of the long co-evolution between bacteria and humans” says Coscolla. “A deeper understanding of these evolutionary processes is crucial to develop a new vaccine against the deadly disease.”