Gene therapy with lipopolysaccharide binding protein for gram-negative pneumonia: respiratory physiology.
BACKGROUND
Lipopolysaccharide binding protein (LBP) plays an essential role in the pulmonary immune response to gram-negative bacterial infection. LBP knockout mice with gram-negative pneumonia have increased mortality compared with wild-type controls. This mortality difference can be abolished with systemic LBP gene therapy. We postulate that LBP knockout mice will develop derangements in lung physiology from gram-negative pneumonia and that these changes can be reversed with systemic LBP gene therapy.


METHODS
Twelve- to 16-week-old C57BL/6 wild-type mice and/or sex, age, matched LBP knockout mice were administered 1 x 10(3) colony-forming units/mouse of Klebsiella pneumoniae by intratracheal inoculation. Treated mice were administered 5 x 10(9) plaque-forming units of recombinant adenovirus containing either the gene for LBP or the irrelevant control protein beta-galactosidase by intravenous injection 2 days before bacterial inoculation. Respiratory physiology parameters were measured preinoculation and 24 hours postbacterial inoculation.


RESULTS
Administration of LBP by systemic gene therapy to LBP knockout mice improved 7-day survival from Klebsiella pneumonia to a level equivalent to wild-type mice exposed to the same dose of bacteria (42 vs. 43% survival). LBP knockout mice given the LBP gene therapy demonstrated increased 14-day survival from Klebsiella pneumonia when compared with controls treated with beta-galactosidase (28 vs. 0%, p < 0.001). LBP knockout mice developed significant differences in respiratory rate, minute ventilation, and enhanced pause (Penh), when compared with wild-type mice with Klebsiella pneumonia. These respiratory derangements were prevented with adenoviral delivery of the LBP gene before K. pneumoniae inoculation.


CONCLUSIONS
Gram-negative pneumonia produces measurable changes in mortality and respiratory physiology between wild-type and LBP knockout mice. These changes can be prevented in LBP knockout mice by systemic gene therapy to restore innate immunity.
Hemmila
Mark R
MR
Department of Surgery, University of Michigan Health System, Ann Arbor, Michigan 48109-0033, USA. mhemmila@umich.edu
Kim
Jiyoun
J
Sun
Jian M
JM
Cannon
Jennifer
J
Arbabi
Saman
S
Minter
Rebecca M
RM
Su
Grace L
GL
Remick
Daniel G
DG
Wang
Stewart C
SC
D000209:Acute-Phase Proteins / Q000235:genetics* / Q000276:immunology; D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000276:immunology; D004195:Disease Models, Animal; D015316:Genetic Therapy; D007113:Immunity, Innate; D007710:Klebsiella Infections / Q000276:immunology / Q000401:mortality / Q000628:therapy*; D007711:Klebsiella pneumoniae; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018410:Pneumonia, Bacterial / Q000276:immunology / Q000401:mortality / Q000628:therapy*; D012143:Respiratory Physiological Phenomena; D015996:Survival Rate; D001616:beta-Galactosidase / Q000378:metabolism; D000099231:Lipopolysaccharide-Binding Protein
D000209:Acute-Phase Proteins; D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D001616:beta-Galactosidase; D000099231:Lipopolysaccharide-Binding Protein