title: Genetic replacement of surfactant protein-C reduces respiratory syncytial virus induced lung injury.
abstract: BACKGROUND
  Individuals with deficiencies of pulmonary surfactant protein C (SP-C) develop interstitial lung disease (ILD) that is exacerbated by viral infections including respiratory syncytial virus (RSV). SP-C gene targeted mice (Sftpc -/-) lack SP-C, develop an ILD-like disease and are susceptible to infection with RSV.
  
  
  METHODS
  In order to determine requirements for correction of RSV induced injury we have generated compound transgenic mice where SP-C expression can be induced on the Sftpc -/- background (SP-C/Sftpc -/-) by the administration of doxycycline (dox). The pattern of induced SP-C expression was determined by immunohistochemistry and processing by Western blot analysis. Tissue and cellular inflammation was measured following RSV infection and the RSV-induced cytokine response of isolated Sftpc +/+ and -/- type II cells determined.
  
  
  RESULTS
  After 5 days of dox administration transgene SP-C mRNA expression was detected by RT-PCR in the lungs of two independent lines of bitransgenic SP-C/Sftpc -/- mice (lines 55.3 and 54.2). ProSP-C was expressed in the lung, and mature SP-C was detected by Western blot analysis of the lavage fluid from both lines of SP-C/Sftpc -/- mice. Induced SP-C expression was localized to alveolar type II cells by immunostaining with an antibody to proSP-C. Line 55.3 SP-C/Sftpc -/- mice were maintained on or off dox for 7 days and infected with 2.6x107 RSV pfu. On day 3 post RSV infection total inflammatory cell counts were reduced in the lavage of dox treated 55.3 SP-C/Sftpc -/- mice (p = 0.004). The percentage of neutrophils was reduced (p = 0.05). The viral titers of lung homogenates from dox treated 55.3 SP-C/Sftpc -/- mice were decreased relative to 55.3 SP-C/Sftpc -/- mice without dox (p = 0.01). The cytokine response of Sftpc -/- type II cells to RSV was increased over that of Sftpc +/+ cells.
  
  
  CONCLUSIONS
  Transgenic restoration of SP-C reduced inflammation and improved viral clearance in the lungs of SP-C deficient mice. The loss of SP-C in alveolar type II cells compromises their response to infection. These findings show that the restoration of SP-C in Sftpc -/- mice in response to RSV infection is a useful model to determine parameters for therapeutic intervention.
authors: Cincinnati Children's Hospital Medical Center, Perinatal Institute, Division of Neonatology, Perinatal and Pulmonary Biology, MLC7029, 3333 Burnet Avenue, Cincinnati, OH 45229-3039, USA. steve.glasser@cchmc.org
authors: Stephan W
authors: SW
authors: Glasser
authors: Albert P
authors: AP
authors: Senft
authors: Melissa D
authors: MD
authors: Maxfield
authors: Teah L
authors: TL
authors: Ruetschilling
authors: John E
authors: JE
authors: Baatz
authors: Kristen
authors: K
authors: Page
authors: Thomas R
authors: TR
authors: Korfhagen
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D015536:Down-Regulation / Q000235:genetics; D055370:Lung Injury / Q000235:genetics / Q000378:metabolism* / Q000517:prevention & control; D051379:Mice; D057507:Mice, 129 Strain; D008822:Mice, Transgenic; D037721:Pulmonary Surfactant-Associated Protein C / Q000096:biosynthesis / Q000235:genetics*; D018357:Respiratory Syncytial Virus Infections / Q000235:genetics* / Q000378:metabolism / Q000517:prevention & control; D012136:Respiratory Syncytial Viruses; D019562:Viral Load / Q000379:methods
chemical_list: D037721:Pulmonary Surfactant-Associated Protein C
references: J Immunol. 2006 Feb 1;176(3):1937-42
references: 16424225
references: Virus Res. 2011 Dec;162(1-2):80-99
references: 21963675
references: Pediatr Res. 2007 Aug;62(2):176-9
references: 17597647
references: Vaccine. 2009 Sep 18;27(41):5620-7
references: 19647064
references: Microbes Infect. 2006 Jul;8(8):2317-23
references: 16782390
references: Am J Physiol Lung Cell Mol Physiol. 2001 Apr;280(4):L705-15
references: 11238011
references: Proc Natl Acad Sci U S A. 2010 Jan 5;107(1):320-5
references: 20080799
references: J Virol. 2005 Mar;79(6):3350-7
references: 15731229
references: Annu Rev Med. 2010;61:105-19
references: 19824815
references: J Biol Chem. 2003 Apr 18;278(16):14291-8
references: 12519727
references: Am J Respir Crit Care Med. 2002 May 1;165(9):1322-8
references: 11991887
references: J Cell Biol. 2006 Jan 30;172(3):395-407
references: 16449190
references: Pediatr Infect Dis J. 2003 Feb;22(2 Suppl):S76-82
references: 12671456
references: J Immunol. 2008 Jul 1;181(1):621-8
references: 18566429
references: Transgenic Res. 2002 Feb;11(1):21-9
references: 11874100
references: Am J Respir Cell Mol Biol. 2004 Aug;31(2):193-9
references: 15016617
references: J Virol. 2002 Jul;76(13):6800-14
references: 12050393
references: Vaccine. 2011 Jul 26;29(33):5368-78
references: 21669246
references: Am J Physiol Lung Cell Mol Physiol. 2009 Jul;297(1):L64-72
references: 19304906
references: Mod Pathol. 2004 Aug;17(8):973-80
references: 15133475
references: Am J Physiol Lung Cell Mol Physiol. 2002 Aug;283(2):L256-64
references: 12114186
references: Am J Respir Cell Mol Biol. 2011 Aug;45(2):189-201
references: 21330463
references: Am J Med Genet A. 2004 Apr 1;126A(1):18-26
references: 15039969
references: Proc Natl Acad Sci U S A. 2001 May 22;98(11):6366-71
references: 11344267
references: Pediatr Res. 2010 Sep;68(3):216-20
references: 20539253
references: J Immunol. 2006 Feb 1;176(3):1733-40
references: 16424203
references: Am J Respir Cell Mol Biol. 2013 Nov;49(5):845-54
references: 23795648
references: Am J Physiol Lung Cell Mol Physiol. 2011 Aug;301(2):L148-56
references: 21571908
references: J Clin Invest. 1999 Apr;103(7):1015-21
references: 10194474
references: J Vet Med B Infect Dis Vet Public Health. 2000 Sep;47(7):535-50
references: 11048435
references: Paediatr Respir Rev. 2011 Dec;12(4):223-9
references: 22018035
references: Am J Respir Cell Mol Biol. 2006 May;34(5):519-20
references: 16618785
references: N Engl J Med. 2001 Feb 22;344(8):573-9
references: 11207353
references: Proc Natl Acad Sci U S A. 1994 Sep 27;91(20):9302-6
references: 7937760
references: J Biol Chem. 2000 Apr 21;275(16):11858-64
references: 10766812