In vivo transduction of cerebellar Purkinje cells using adeno-associated virus vectors

We investigated whether adenovirus or adeno-associated virus vectors can transduce cerebellar Purkinje cells (PCs) in vivo. M ice were injected in the deep cerebellar nuclei (DCN) with lacZ-transducing adenovirus (Ad.RSV-βgal) or a recombinant AAV serotype 2 (rAAV2) vector (vTR-CM Vβ) mixed with wild-type adenovirus type 5 (Ad5). One week later, Ad.RSV-βgal transduced cells were found throughout the cerebellar white matter in a dose-dependent manner, but few transduced PCs were evident. In contrast, vTR-CM Vβ with Ad5 transduced several hundred PCs throughout the injected hemisphere. Using an rAAV2 vector transducing a CM V-regulated green fluorescent protein gene, we again found PC transduction, but only with Ad5 coinjection. To assess the effect of injection site and to determine whether the apparent requirement for Ad5 coinfection is observed with other promoters, a β-actin-regulated vector was injected with or without Ad5 to DCN or cerebellar cortical sites. Thousands of transduced PCs were observed under each condition. Cortical injection yielded greater numbers of transduced cells. Injection of rAAV2 without AdS led to greater specificity for PC transduction. We conclude that injection of rAAV2 vectors into the cerebellum is an effective means for transferring genes into substantial numbers of Purkinje cells in vivo.