title: Use of induced pluripotent stem cells to recapitulate pulmonary alveolar proteinosis pathogenesis.
abstract: BACKGROUND
  In patients with pulmonary alveolar proteinosis (PAP) syndrome, disruption of granulocyte/macrophage colony-stimulating factor (GM-CSF) signaling is associated with pathogenic surfactant accumulation from impaired clearance in alveolar macrophages.
  
  
  OBJECTIVE
  The aim of this study was to overcome these barriers by using monocyte-derived induced pluripotent stem (iPS) cells to recapitulate disease-specific and normal macrophages.
  
  
  METHODS
  We created iPS cells from two children with hereditary PAP (hPAP) caused by recessive CSF2RA(R217X) mutations and three normal people, differentiated them into macrophages (hPAP-iPS-Mφs and NL-iPS-Mφs, respectively), and evaluated macrophage functions with and without gene-correction to restore GM-CSF signaling in hPAP-iPS-Mφs.
  
  
  RESULTS
  Both hPAP and normal iPS cells had human embryonic stem cell-like morphology, expressed pluripotency markers, formed teratomas in vivo, had a normal karyotype, retained and expressed mutant or normal CSF2RA genes, respectively, and could be differentiated into macrophages with the typical morphology and phenotypic markers. Compared with normal, hPAP-iPS-Mφs had impaired GM-CSF receptor signaling and reduced GM-CSF-dependent gene expression, GM-CSF- but not M-CSF-dependent cell proliferation, surfactant clearance, and proinflammatory cytokine secretion. Restoration of GM-CSF receptor signaling corrected the surfactant clearance abnormality in hPAP-iPS-Mφs.
  
  
  CONCLUSIONS
  We used patient-specific iPS cells to accurately reproduce the molecular and cellular defects of alveolar macrophages that drive the pathogenesis of PAP in more than 90% of patients. These results demonstrate the critical role of GM-CSF signaling in surfactant homeostasis and PAP pathogenesis in humans and have therapeutic implications for hPAP.
authors.affiliation: 1 Division of Pulmonary Biology.
authors.forename: Takuji
authors.initials: T
authors.lastname: Suzuki
authors.forename: Christopher
authors.initials: C
authors.lastname: Mayhew
authors.forename: Anthony
authors.initials: A
authors.lastname: Sallese
authors.forename: Claudia
authors.initials: C
authors.lastname: Chalk
authors.forename: Brenna C
authors.initials: BC
authors.lastname: Carey
authors.forename: Punam
authors.initials: P
authors.lastname: Malik
authors.forename: Robert E
authors.initials: RE
authors.lastname: Wood
authors.forename: Bruce C
authors.initials: BC
authors.lastname: Trapnell
mesh_terms: D016022:Case-Control Studies; D002454:Cell Differentiation; D002478:Cells, Cultured; D002648:Child; D018014:Gene Transfer Techniques; D040181:Genetic Diseases, X-Linked / Q000503:physiopathology*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000502:physiology; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000378:metabolism*; D016676:Macrophages, Alveolar / Q000378:metabolism; D011649:Pulmonary Alveolar Proteinosis / Q000503:physiopathology*; D011663:Pulmonary Surfactants / Q000378:metabolism*; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / Q000172:deficiency* / Q000235:genetics / Q000627:therapeutic use; D015398:Signal Transduction
chemical_list: C521678:CSF2RA protein, human; D011663:Pulmonary Surfactants; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor