Pseudomonas aeruginosa (Pa) respiratory infection is accompanied by the immune system’s over-activation, followed by chronic inflammation that ends up severely damaging the CF lung. The anti-inflammatory drugs nowadays available cannot selectively target the pathogenic immune system’s response. To address this issue, it would be important to know the molecular mechanisms through which Pa and the immune system interact. A new class of T lymphocytes (Th1/17) has recently been discovered, which have shown to be excessively activated by Pa clinical strains isolated after years of persistence in the CF lungs. The aim of the project is to identify the molecular mechanisms that induce the proliferation of Th1/17 lymphocytes because of Pa. Thanks to functional immunological approaches and advanced molecular biology techniques, such as massive RNA sequencing, the Th1/17 lymphocyte’s genes and the Pa responsible for their activation will be studied. The prospect is to identify new therapeutic targets with the ultimate goal of finding a more selective, thus effective, anti-inflammatory drug.