Adenovirus vector-directed expression of the neurotrophin-3 receptor (TrkC) in mouse astrocytes

In the present article we report the generation of a neurovirological reagent, an adenovirus vector that efficiently delivers the gene for the Neurotrophin-3 (NT-3) receptor, TrkC. Using this AdTrkC vector, we examined the induction of the expression of the above neurotrophin receptor in pure cultures of mouse astrocytes, a glial cell type that does not constitutively express this gene. Infection of astrocytes at an optimal dose of 100-200 plaque forming units (p.f.u.) per cell, induced expression of specific mRNA, as demonstrated by RT-PCR and Northern blot. This mRNA was translated to produce a mean of 20,157 biologically active receptor molecules per astrocyte with a Kd of 4.1 x 10(-11) M, as demonstrated by 125I-NT-3 binding. After 2D electrophoresis, the mature glycoprotein and some precursors were recognised by antibodies raised against the carboxy-terminal peptide of Trk. Binding of the ligand induced autophosphorylation ofTrkC and 3H-thymidine incorporation in transduced cells. These results demonstrate that our AdTrkC vector efficiently mediates the expression of high-levels of biologically active NT-3 receptors.