The Bottini laboratory focuses on signaling pathways relevant to the etiopathogenesis and/or therapy of systemic autoimmunity. We specialize in the study of protein phosphatases, enzymes that control intracellular signaling by balancing the action of tyrosine kinases. A long-standing research line in the laboratory is focused on understanding the immunological mechanism of action of the tyrosine phosphatase PTPN22 that is encoded by a major autoimmunity gene. A second research line is focused on signaling in fibroblast-like synoviocytes, an important cell type that invades and destroys the joint in rheumatoid arthritis. Several lines of evidence suggest that targeting these cells would be beneficial for therapy of inflammatory arthritis. However the signal transduction pathways controlling the behavior of fibroblast-like synoviocytes are only partially understood. We are systematically studying the role of phosphatases in these cells, with the goal to identify molecules and pathways that can be harnessed for development of novel therapies.