Monoclonal antibodies are increasingly used in clinical practice to treat cancers, inflammatory diseases and infectious diseases. They also represent a very promising alternative to antibiotics in the fight against multi-resistant bacteria. This project aims to isolate for therapeutic purposes human monoclonal antibodies targeting virulence factors of Pseudomonas aeruginosa. P. aeruginosa is becoming increasingly resistant to antibiotics and thus an important global public health threat. Furthermore, this bacterium is highly prevalent in cystic fibrosis patients and its acquisition is a major predictor of the severity of this disease. We have chosen to target two essential virulence factors of P. aeruginosa, the type III secretion system proteins PcrV, PscF,and PopB/PopD), and the type Vb secretion system protein Pdta protein. We propose to isolate and characterize human monoclonal antibodies against these factors in order to develop them as therapeutic molecules.