In this study, T cell plasticity and survival and the role of different damage-associated molecular patterns, prostaglandins, and bacterial superantigens in chronic rhinosinutisis will be studied. The role of the specific mucosal milieu on T cell plasticity will be analyzed in vitro, in vivo in Rag2-/-yc-/-knockout mice transplanted with human inflamed mucosa, and ex vivo in human nasal mucosal tissue.