Green fluorescent protein as a reporter for retrovirus and helper virus-free HSV-1 amplicon vector-mediated gene transfer into neural cells in culture and in vivo

Abstract

Green fluorescent protein (GFP) is an effective marker for retrovirus and herpes virus vector-mediated gene transfer into various central nervous system-derived cells, both proliferative and non-proliferative, in culture and in vivo. Retrovirus vectors were used to stably transduce several rat and human glioma lines, and a multipotent mouse neural progenitor line in culture. Implantation of selected pools of transduced glioma cells into rodent brain allowed clear visualization of the tumor and the invading tumor edge. Helper virus-free HSV-1 amplicon vectors successfully transferred gfp into non-dividing primary neural cells in culture and in the rat brain. This study describes the versatility of GFP for: (i) labelling of glioma cells in experimental brain tumor models and neural progenitor cells by retrovirus vectors, and (ii) efficient, non-toxic delivery of genes to post mitotic cells of the nervous system using helper-virus free HSV-1 amplicon vectors.

Quantitation of HSV mass distribution in a rodent brain tumor model

“…Multiple marker genes are under investigation for in vivo imaging. Optical candidates include luciferase, 32 GFP, 33 protease activatable fluoroscopic dyes, 34 while MR techniques include engineered internalizing receptors 35 or tyrosinase. 36 PET agents include reporter probes such as FESP (an agonist for dopamine receptors) 37 and 18-FIAU or 18-F gancyclovir/pencyclovir for imaging thymidine kinase.…”

Herpes simplex virus type-1 infection upregulates cellular promoters and telomerase activity in both tumor and nontumor human cells

“…It is not unreasonable to predict that nonherpes viral vectors may have similar effects on host cells. For HSV-1, it seems safer to use vectors with multiple deletions of all IE genes 69,70 or virus-free amplicons [71][72][73][74] for gene transfer to nontumoral tissues. For oncolytic viral vectors, it might be plausible to put the IE genes, particularly the ICP0 and 4, under strict cell-type specific control to reduce their expression in normal cells.…”

Variability in infectivity of primary cell cultures of human brain tumors with HSV-1 amplicon vectors

“…[5][6][7][8][9][10][11][12] The helper virus-free HSV-1 amplicon has been shown to be a safe and efficient vector system in culture and in vivo to transduce various central nervous system-derived cells including human gliomas. 8,[13][14][15][16] Further development of gene therapy protocols for use in patients is an important, but, according to experience, also quite a challenging issue. This could be due to, at least in part, different responsiveness of different tumor types to (i) the gene paradigm used (eg prodrug therapy), and also (ii) to the interindividual variability of cells within the same tumor to vector infectivity.…”