title: PI(3)P-p40phox binding regulates NADPH oxidase activation in mouse macrophages and magnitude of inflammatory responses in vivo.
abstract: Mutations in the leukocyte NADPH oxidase that abrogate superoxide production result in chronic granulomatous disease (CGD), an inherited immunodeficiency associated with recurrent infections and inflammatory complications. The cytosolic regulatory subunit p40phoxplays a specialized role in stimulating NADPH oxidase activity on intracellular membranes via its phosphatidylinositol 3-phosphate [PI(3)P]-binding domain, as revealed by studies largely focused on neutrophils. Whether PI(3)P-p40phox-regulated superoxide production contributes to regulating inflammatory responses is not well understood. Here, we report that mice expressing p40phoxR58A, which lacks PI(3)P binding, had impaired macrophage NADPH oxidase activity and increased sterile inflammation. p40phoxR58A/R58Amacrophages exhibited diminished phagosome reactive oxygen species (ROS) in response to certain particulate and soluble ligands, including IgG-opsonized particles and a TLR2 agonist, along with unexpected defects in plasma membrane oxidase activity. Compared with wild-type (WT) mice, p40phoxR58A/R58Amice had elevated numbers of newly recruited neutrophils and monocytes in peritoneal inflammation elicited by zymosan, monosodium urate (MSU) crystals, or sodium periodate. At later time points, higher numbers of inflammatory macrophages in p40phoxR58A/R58Amice were consistent with delayed resolution. Our studies demonstrate a critical role of PI(3)P-p40phoxbinding for optimal activation of the NADPH oxidase in macrophages. Furthermore, selective loss of PI(3)P-regulated NADPH oxidase activity was sufficient to enhance significantly responses to inflammation and delay resolution.
authors.affiliation: Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; and.
authors.forename: Juhi
authors.initials: J
authors.lastname: Bagaitkar
authors.affiliation: Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; and.
authors.forename: Emilia A
authors.initials: EA
authors.lastname: Barbu
authors.affiliation: Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; and.
authors.forename: Lizet J
authors.initials: LJ
authors.lastname: Perez-Zapata
authors.affiliation: Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; and.
authors.forename: Anthony
authors.initials: A
authors.lastname: Austin
authors.affiliation: Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; and.
authors.forename: Guangming
authors.initials: G
authors.lastname: Huang
authors.affiliation: Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; and.
authors.forename: Sabine
authors.initials: S
authors.lastname: Pallat
authors.affiliation: Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA; and dinauer_m@kids.wustl.edu.|Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA.
authors.forename: Mary C
authors.initials: MC
authors.lastname: Dinauer
mesh_terms: D000067531:Alarmins / Q000378:metabolism; D000818:Animals; D007249:Inflammation / Q000378:metabolism* / Q000473:pathology*; D008024:Ligands; D017737:Macrophages, Peritoneal / Q000201:enzymology* / Q000473:pathology*; D008810:Mice, Inbred C57BL; D010587:Phagocytosis; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D011485:Protein Binding; D017382:Reactive Oxygen Species / Q000378:metabolism; D051193:Toll-Like Receptors / Q000819:agonists / Q000378:metabolism
chemical_list: D000067531:Alarmins; D008024:Ligands; D018129:Phosphatidylinositol Phosphates; D010750:Phosphoproteins; D017382:Reactive Oxygen Species; D051193:Toll-Like Receptors; C085072:neutrophil cytosol factor 40K; C055525:phosphatidylinositol 3-phosphate
keywords: CGD; ROS; sterile inflammation