Ss. Gambhir et al., A mutant herpes simplex virus type 1 thymidine kinase reporter gene shows improved sensitivity for imaging reporter gene expression with positron emission tomography, P NAS US, 97(6), 2000, pp. 2785-2790
Citations number
21
Categorie Soggetti
Multidisciplinary
Journal title
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
We are developing assays for noninvasive, quantitative imaging of reporter
genes with positron emission tomography (PET), for application both in anim
al models and in human gene therapy. We report here a method to improve the
detection of lower levels of PET reporter gene expression by utilizing a m
utant herpes simplex virus type 1 thymidine kinase (HSV1-sr39tk) as a PET r
eporter gene. The HSV1-sr39tk mutant was identified from a library of site-
directed mutants. Accumulation (net uptake) of the radioactively labeled su
bstrates [8-H-3]penciclovir ([8-H-3]PCV), and 8-[F-18]fluoropenciclovir (FP
CV) in C6 rat glioma cells expressing HSV1-sr39tk is increased by a factor
of approximate to 2.0 when compared with C6 cells expressing wild-type HSV1
-tk, The increased imaging sensitivity of HSV1-sr39tk when FPCV is used is
also demonstrated in vivo both with tumor cells stably transfected with eit
her HSV1-tk or HSV1-sr39tk, and after hepatic delivery of HSV1-tk or HSV1-s
r39tk by using adenoviral vectors. The use of HSV1-sr39tk as a PET reporter
gene and FPCV as a PET reporter probe results in significantly enhanced se
nsitivity for imaging reporter gene expression in vivo.