Recombinant adeno-associated virus type 2,4, and 5 vectors: Transduction of variant cell types and regions in the mammalian central nervous svstem

摘要

Recombinant adeno-associated virus vectors based on serotype 2 (rAAV2) can direct transgene expression in the central nervous system (CNS), but it is not known how other rAAV serotypes perform as CNS gene transfer vectors. Serotypes 4 and S are distinct from rAAV2 and from each other in their capsid regions, suggesting that they may direct binding and entry into different cell types. In this study. We examined the tropisms and transduction efficiencies of beta-galactosidase-encoding vectors made from rAAV4 and rAAVS compared with similarly designed rAAV2-based vectors. injection of rAAV5 p-galactosidase (βpgal) or rAAV4pgal into the lateral ventricle resulted in stable transduction of ependymal cells, with approximately 10-fold more positive cells than in mice injected with rAAV2pgaI. Major differences between the three vectors were revealed upon striatal injections. intrastriatal injection of rAAV4pgaI resulted again in striking ependyma-specific expression of transgene, with a notabIe absence of transduced ceIls in the parenchyma. rAAV2pgaI and rAAVSβgal intrastriatal injections led to p-gal-positive parenchymal cells, but, unlike rAAV2pgaI. rAAV5pgal transduced both neurons and astrocytes. The number of transgene-positive cells in rAAV5pgal-injected brains was 130 and S.000 times higher than in rAAV2pgal-injected brains at 3 and 15 wk, respectively. Moreover. transgene-positive cells were widely dispersed throughout the injected hemisphere in rAAV5pgaI-transduced animals. Together, our data provide in vivo support for earlier in vitro work, suggesting that rAAV4 and rAAV5 gain cell entry by means of receptors distinct from rAAV2. These differences could be exploited to improve gene therapy for CNS disorders.