title: A secretory leukocyte protease inhibitor variant with improved activity against lung infection.
abstract: Secretory leukocyte protease inhibitor (SLPI) is an important respiratory tract host defense protein, which is proteolytically inactivated by excessive neutrophil elastase (NE) during chronic Pseudomonas infection in the cystic fibrosis (CF) lung. We generated two putative NE-resistant variants of SLPI by site-directed mutagenesis, SLPI-A16G and SLPI-S15G-A16G, with a view to improving SLPI's proteolytic stability. Both variants showed enhanced resistance to degradation in the presence of excess NE as well as CF patient sputum compared with SLPI-wild type (SLPI-WT). The ability of both variants to bind bacterial lipopolysaccharides and interact with nuclear factor-κB DNA binding sites was also preserved. Finally, we demonstrate increased anti-inflammatory activity of the SLPI-A16G protein compared with SLPI-WT in a murine model of pulmonary Pseudomonas infection. This study demonstrates the increased stability of these SLPI variants compared with SLPI-WT and their therapeutic potential as a putative anti-inflammatory treatment for CF lung disease.
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, Northern Ireland, UK.
authors.forename: N
authors.initials: N
authors.lastname: Camper
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, Northern Ireland, UK.
authors.forename: A M A
authors.initials: AM
authors.lastname: Glasgow
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, Northern Ireland, UK.
authors.forename: M
authors.initials: M
authors.lastname: Osbourn
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, Northern Ireland, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Quinn
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, Northern Ireland, UK.
authors.forename: D M
authors.initials: DM
authors.lastname: Small
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, Northern Ireland, UK.
authors.forename: D T
authors.initials: DT
authors.lastname: McLean
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, Northern Ireland, UK.
authors.forename: F T
authors.initials: FT
authors.lastname: Lundy
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, Northern Ireland, UK.
authors.forename: J S
authors.initials: JS
authors.lastname: Elborn
authors.affiliation: Our Lady's Children's Hospital, Crumlin, Ireland, UK.
authors.forename: P
authors.initials: P
authors.lastname: McNally
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, Northern Ireland, UK.
authors.forename: R J
authors.initials: RJ
authors.lastname: Ingram
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, Northern Ireland, UK.
authors.forename: S
authors.initials: S
authors.lastname: Weldon
authors.affiliation: Centre for Infection and Immunity, Queen's University Belfast, Belfast, Northern Ireland, UK.
authors.forename: C C
authors.initials: CC
authors.lastname: Taggart
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002908:Chronic Disease; D003550:Cystic Fibrosis / Q000150:complications / Q000276:immunology*; D004195:Disease Models, Animal; D006801:Humans; D007113:Immunity, Innate; D019272:Leukocyte Elastase / Q000378:metabolism*; D008168:Lung / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D008810:Mice, Inbred C57BL; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D020556:Neutrophil Infiltration; D059748:Proteolysis; D011552:Pseudomonas Infections / Q000150:complications / Q000276:immunology*; D011550:Pseudomonas aeruginosa / Q000276:immunology*; D053481:Secretory Leukocyte Peptidase Inhibitor / Q000235:genetics / Q000378:metabolism*
chemical_list: C506814:SLPI protein, human; D053481:Secretory Leukocyte Peptidase Inhibitor; D019272:Leukocyte Elastase