title: Repetitive imaging of reporter gene expression in the lung.
abstract: Positron emission tomographic imaging is emerging as a powerful technology to monitor reporter transgene expression in the lungs and other organs. However, little information is available about its usefulness for studying gene expression over time. Therefore, we infected 20 rats with a replication-deficient adenovirus containing a fusion gene encoding for a mutant Herpes simplex virus type-1 thymidine kinase and an enhanced green fluorescent protein. Five additional rats were infected with a control virus. Pulmonary gene transfer was performed via intratracheal administration of vector using a surfactant-based method. Imaging was performed 4-6 hr, and 4, 7, and 10 days after gene transfer, using 9-(4-[18F]-fluoro-3-hydroxymethylbutyl)guanine, an imaging substrate for the mutant kinase. Lung tracer uptake assessed with imaging was moderately but significantly increased 4-6 hr after gene transfer, was maximal after 4 days, and was no longer detectable by 10 days. The temporal pattern of transgene expression measured ex vivo with in vitro assays of thymidine kinase activity and green fluorescent protein was similar to imaging. In conclusion, positron emission tomography is a reliable new tool to evaluate the onset and duration of reporter gene expression noninvasively in the lungs of intact animals.
authors.affiliation: Washington University School of Medicine in St. Louis, MO 63110, USA.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Richard
authors.forename: Philip
authors.initials: P
authors.lastname: Factor
authors.forename: Thomas
authors.initials: T
authors.lastname: Ferkol
authors.forename: Datta E
authors.initials: DE
authors.lastname: Ponde
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Zhou
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Schuster
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D020869:Gene Expression Profiling / Q000379:methods*; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins; D007700:Kinetics; D008164:Luminescent Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D008168:Lung / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018139:Simplexvirus / Q000235:genetics; D013937:Thymidine Kinase / Q000235:genetics / Q000378:metabolism; D014055:Tomography, Emission-Computed / Q000379:methods*; D019076:Transgenes
chemical_list: D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D013937:Thymidine Kinase