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

We investigated whether adenovirus or adeno-associated virus vectors can tr ansduce cerebellar Purkinje cells (PCs) in vivo. Mice were injected in the deep cerebellar nuclei (DCN) with lacZ-transducing adenovirus (Ad.RSV-beta gal) or a recombinant AAV serotype 2 (rAAV2) vector (VTR-CMV beta) mixed wi th wild-type adenovirus type 5 (Ad5). One week later, Ad.RSV-beta gal trans duced cells were found throughout the cerebellar white matter in a dose-dep endent manner, but few transduced PCs were evident. In contrast, vTR-CMV be ta with Ad5 transduced several hundred PCs throughout the injected hemisphe re. Using an rAAV2 vector transducing a CMV-regulated green fluorescent pro tein gene, we again found PC transduction, but only with Ad5 coinjection. T o assess the effect of injection site and to determine whether the apparent requirement for Ad5 coinfection is observed with other promoters, a beta - actin-regulated vector was injected with or without Ad5 to DCN or cerebella r cortical sites. Thousands of transduced PCs were observed under each cond ition. Cortical injection yielded greater numbers of transduced cells. Inje ction of rAAV2 without Ad5 led to greater specificity for PC transdudion. W e conclude that injection of rAAV2 vectors into the cerebellum is an effect ive means for transferring genes into substantial numbers of Purkinje cells in vivo.