HERPES VIRUS-BASED VECTORS

Herpesviruses are a diverse family of large DNA viruses, all of which have the capacity to establish lifelong latent infections. Many differ ent herpesviruses may have potential as gene delivery vehicles, but ex ploitation of this potential has, to date, been explored only using He rpes simplex virus (HSV), a virus which naturally establishes a silent , latent infection of neurones in man and in a number of experimental animal models. Delivery of reporter genes in vitro and in vivo has bee n demonstrated using a variety of replication competent and replicatio n defective vectors, and significant physiological modification in the CNS has been achieved by HSV-mediated gene delivery. Much remains to be done using animal models and, in particular, the requirements for l ong-term gene expression from latent virus genomes needs to be defined in different cell types in vivo.