Bioluminescent detection of endotoxin effects on HIV-1 LTR-driven transcription in vivo.
We investigated the effects of Gram-negative bacterial lipopolysaccharide (LPS) on luciferase expression in transgenic reporter mice in which luciferase expression is driven by the nuclear factor kappaB (NF-kappaB)-dependent portion of the human immunodeficiency virus-1 (HIV-1) long terminal repeat (HIV-1 LTR). Using these mice, we dissected the sources of luciferase activity at the organ level by (a) assessing luciferase activity in organ homogenates, (b) bioluminescence imaging in vivo, and (c) bioluminescence imaging of individual organs ex vivo. Luciferin dosage was a critical determinant of the magnitude of photon emission from these reporter mice. Photon emission increased at doses from 0.5-6 mg of luciferin given by intraperitoneal (IP) injection. The differential between basal and LPS-induced bioluminescence was maximal at 3-6 mg of luciferin. Luciferase expression was highly inducible in lungs, liver, spleen, and kidneys after a single IP injection of LPS, as assessed by luciferase activity measurements in organ homogenates. Luciferase activity was also induced in the forebrain by treatment with IP LPS. In contrast, aerosolized LPS produced a response localized to the lungs as assessed by both bioluminescence and ex vivo luciferase assay measurements. These studies demonstrate the utility of luciferase reporter mice for determining organ-specific gene expression in response to local and systemic stimuli.
Yull
Fiona E
FE
Department of Medicine, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2650, USA.
Han
Wei
W
Jansen
E Duco
ED
Everhart
M Brett
MB
Sadikot
Ruxana T
RT
Christman
John W
JW
Blackwell
Timothy S
TS
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004731:Endotoxins / Q000008:administration & dosage / Q000494:pharmacology*; D004926:Escherichia coli; D049454:Firefly Luciferin; D005456:Fluorescent Dyes; D016325:HIV Long Terminal Repeat; D015497:HIV-1 / Q000235:genetics*; D007274:Injections, Intraperitoneal; D007700:Kinetics; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000494:pharmacology; D008156:Luciferases / Q000096:biosynthesis; D008163:Luminescent Measurements; D008168:Lung / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D009928:Organ Specificity; D014158:Transcription, Genetic
D004731:Endotoxins; D005456:Fluorescent Dyes; D008070:Lipopolysaccharides; D049454:Firefly Luciferin; C044101:endotoxin, Escherichia coli; D008156:Luciferases