title: Intratracheal instillation of high dose adenoviral vectors is sufficient to induce lung injury and fibrosis in mice.
abstract: BACKGROUND
  Replication deficient adenoviruses (Ad) vectors are common tools in gene therapy. Since Ad vectors are known to activate innate and adaptive immunity, we investigated whether intratracheal administration of Ad vectors alone is sufficient to induce lung injury and pulmonary fibrosis.
  
  
  METHODS
  We instilled Ad viruses ranging from 107 to 1.625×109 ifu/mouse as well as the same volume of PBS and bleomycin. 14 and 21 days after administration, we collected bronchoalveolar lavage fluid (BALF) and mouse lung tissues. We measured the protein concentration, total and differential cell counts, and TGF-β1 production, performed Trichrome staining and Sircol assay, determined gene and protein levels of profibrotic cytokines, MMPs, and Wnt signaling proteins, and conducted TUNEL staining and co-immunofluorescence for GFP and α-SMA staining.
  
  
  RESULTS
  Instillation of high dose Ad vectors (1.625×109 ifu/mouse) into mouse lungs induced high levels of protein content, inflammatory cells, and TGF-β1 in BALF, comparable to those in bleomycin-instilled lungs. The collagen content and mRNA levels of Col1a1, Col1a2, PCNA, and α-SMA were also increased in the lungs. Instillation of both bleomycin and Ad vectors increased expression levels of TNFα and IL-1β but not IL-10. Instillation of bleomycin but not Ad increased the expression of IL-1α, IL-13 and IL-16. Treatment with bleomycin or Ad vectors increased expression levels of integrin α1, α5, and αv, MMP9, whereas treatment with bleomycin but not Ad vectors induced MMP2 expression levels. Both bleomycin and Ad vectors induced mRNA levels of Wnt2, 2b, 5b, and Lrp6. Intratracheal instillation of Ad viruses also induced DNA damages and Ad viral infection-mediated fibrosis is not limited to the infection sites.
  
  
  CONCLUSIONS
  Our results suggest that administration of Ad vectors induces an inflammatory response, lung injury, and pulmonary fibrosis in a dose dependent manner.
authors.affiliation: Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Qiyuan
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Tianji
authors.initials: T
authors.lastname: Chen
authors.affiliation: Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Melike
authors.initials: M
authors.lastname: Bozkanat
authors.affiliation: Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States of America; Children's Hospital University of Illinois, Chicago, Illinois, United States of America.
authors.forename: Joyce Christina F
authors.initials: JC
authors.lastname: Ibe
authors.affiliation: Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, The Ohio State University, Columbus, Ohio, United States of America.
authors.forename: John W
authors.initials: JW
authors.lastname: Christman
authors.affiliation: Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States of America; Children's Hospital University of Illinois, Chicago, Illinois, United States of America.
authors.forename: J Usha
authors.initials: JU
authors.lastname: Raj
authors.affiliation: Department of Pediatrics, University of Illinois at Chicago, Chicago, Illinois, United States of America; University of Illinois Cancer Center, University of Illinois at Chicago, Chicago, Illinois, United States of America.
authors.forename: Guofei
authors.initials: G
authors.lastname: Zhou
mesh_terms: D000199:Actins / Q000096:biosynthesis; D000256:Adenoviridae / Q000276:immunology*; D000818:Animals; D001761:Bleomycin / Q000008:administration & dosage*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D024042:Collagen Type I / Q000096:biosynthesis; D000090602:Collagen Type I, alpha 1 Chain; D004195:Disease Models, Animal; D007249:Inflammation / Q000276:immunology* / Q000821:virology; D016023:Integrins / Q000096:biosynthesis; D018793:Interleukin-13 / Q000096:biosynthesis; D019410:Interleukin-16 / Q000096:biosynthesis; D053582:Interleukin-1alpha / Q000096:biosynthesis; D053583:Interleukin-1beta / Q000096:biosynthesis; D055370:Lung Injury / Q000276:immunology* / Q000821:virology; D008297:Male; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis; D011658:Pulmonary Fibrosis / Q000276:immunology* / Q000821:virology; D053773:Transforming Growth Factor beta1 / Q000096:biosynthesis; D051153:Wnt Proteins / Q000096:biosynthesis
chemical_list: D000199:Actins; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; C587672:IL1B protein, mouse; D016023:Integrins; D018793:Interleukin-13; D019410:Interleukin-16; D053582:Interleukin-1alpha; D053583:Interleukin-1beta; D018809:Proliferating Cell Nuclear Antigen; D053773:Transforming Growth Factor beta1; D051153:Wnt Proteins; C544013:alpha-smooth muscle actin, mouse; D001761:Bleomycin; D020778:Matrix Metalloproteinase 2; C522362:Mmp2 protein, mouse; D020780:Matrix Metalloproteinase 9; C501830:Mmp9 protein, mouse