RT Journal Article SR Electronic T1 Noninvasive Molecular Imaging to Detect Transgene Expression of Lentiviral Vector in Nonhuman Primates JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1212 OP 1219 VO 47 IS 7 A1 Sander, William E. A1 Metzger, Mark E. A1 Morizono, Kouki A1 Bonifacino, Aylin A1 Penzak, Scott R. A1 Xie, Yi-Ming A1 Chen, Irvin S.Y. A1 Bacon, Jeffrey A1 Sestrich, Stephen G. A1 Szajek, Lawrence P. A1 Donahue, Robert E. YR 2006 UL http://jnm.snmjournals.org/content/47/7/1212.abstract AB Noninvasive imaging of a reporter gene is a new and promising technique to quantify transgene expression after gene therapy. This study was performed to demonstrate visualization of lentiviral-marked cells by PET. Methods: We transduced nonhuman primate CD34+ hematopoietic cells with a lentiviral vector expressing a PET reporter gene, the mutant viral herpes simplex virus type 1–thymidine kinase (HSV1-sr39tk) gene. 1-(2-Fluoro-2-deoxy-β-d-arabinofuranosyl)-76Br-5-bromouracil (76Br-FBAU) was used as the substrate for the viral tk enzyme. Upon phosphorylation, 76Br-FBAU was retained by cells and imaged by PET. The long half-life of 76Br, 16.2 h, permitted us to perform extended pharmacokinetic and imaging studies. Results: 76Br-FBAU was retained in vascular tissues of the animals with transplanted tk lentiviral vector–transduced CD34+ cells. Elimination of 76Br-FBAU was through renal and hepatic excretion. Conclusion: Noninvasive molecular imaging using PET will help us, in the future, to define the contribution and distribution of cells and their progeny to tissue repair and development.