Brain Struct Funct. 2010 Aug;215(2):105-13.
Targeting of neural stem cells in the hippocampus of adult rats by custom-made Ad vectors.
Hildebrandt S, Schmidt A, Stoll A, Schmitt O, Köhling R, Wree A, Haas SJP, Pützer BM.
Adult hippocampal neural stem cells (NSC) are an intriguing source for cell replacement or could serve as delivery vehicles for therapeutic genes. We recently reported selective transduction of adult mouse NSC in the DG by in vivo injection of GFP encoding adenoviral (Ad) vectors engineered to bind NSC-specific peptides. Here, we investigated the specificity of these peptide-tagged vectors in the adult rat DG, and whether they can be used to follow differentiation of infected cells over time. The virus-containing solution was injected into the DG by stereotaxic surgery. Specific transduction of NSC was demonstrated by the radial glia-like morphology of GFP-expressing type-1 cells and co-labeling with nestin or glial fibrillary acidic protein. Three days post-injection more than 82% of GFP-containing cells were nestin-immunoreactive, as revealed by unbiased stereology and no GFP-expressing neurons were observed. However, 30 days after injection, the amount of GFP and nestin-containing cells declined (56%), whereas now neurons that contained NeuN or possessed the typical granular nerve cell morphology expressed GFP, indicating that they were derived from initially transduced NSC. Importantly, still more than 20% of nestin-immunoreactive NSC was found to be GFP-positive 90 days after infection, but unfortunately at this time point no GFP-containing neurons were detectable. Our results demonstrate that Ad vectors tagged with NSC-specific ligands can be used to target type-1 NSC, the low-proliferating cell population, in the rat hippocampus. They are a valuable tool to monitor the differentiation of their descendants, at least over short time periods.