Objective Neutrophils are short-lived leukocytes with vital functions in host defense. Neutrophils are massively recruited to extravascular sites in response to danger signals. This immediate, life saving, inflammatory response can turn against the host if its intensity and duration are dysregulated leading to tissue injury and/or failed immune response to pathogens. The dual protective/pathologic role of neutrophils is reflected by the functions of neutrophil serine proteases, potent granule enzymes that hydrolyze other proteins. Neutrophil serine proteases (or NSPs) directly kill pathogens after fusion of the NSP-rich granules with the microbe-containing phagosome. However, when released extracellularly and in excess of the anti-protease shield, NSPs are harmful by fueling the inflammatory response and by destroying extracellular matrix proteins and immune defense proteins. The aim of the proposed work is to investigate the regulation of NSPs by the serpin (SERine Protease INhibitors) family of proteins in health and disease. Specifically, we will study the role of serpinB1, one of the best inhibitors of the three NSPs: neutrophil elastase, cathepsin G and proteinase-3. We have previously shown that (i) serpinB1, a cytoplasmic inhibitor of NSPs carried at high levels in neutrophils, provides a physiological and vital shield against pathologic actions of NSPs during lung infection, and (ii) serpinB1 prevents the early death of neutrophils during infection. Our preliminary data now indicates that serpinB1 is required to preserve the size of the neutrophil reservoir in bone marrow and protects lung epithelial cells against NSPs. The proposed work will elucidate the protective functions of serpinB1 in myeloid cells and lung epithelial cells. Overall, these studies will provide highly significant advances in understanding pathologic mechanisms due to excess NSPs in bone marrow homeostasis and pulmonary disease. Fields of science natural sciencesbiological sciencescell biologymedical and health sciencesbasic medicineimmunologymedical and health sciencesbasic medicinephysiologyhomeostasisnatural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes Programme(s) FP7-PEOPLE - Specific programme "People" implementing the Seventh Framework Programme of the European Community for research, technological development and demonstration activities (2007 to 2013) Topic(s) FP7-PEOPLE-2009-RG - Marie Curie Action: "Reintegration Grants" Call for proposal FP7-PEOPLE-2009-RG See other projects for this call Funding Scheme MC-IRG - International Re-integration Grants (IRG) Coordinator UNIVERSITAET BERN Address Hochschulstrasse 6 3012 Bern Switzerland See on map Region Schweiz/Suisse/Svizzera Espace Mittelland Bern / Berne Activity type Higher or Secondary Education Establishments Administrative Contact Britta Engelhardt (Prof.) Links Contact the organisation Opens in new window Website Opens in new window EU contribution € 100 000,00