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 different herpesviruses may have potential as gene delivery vehicles, but exploitation of this potential has, to date, been explored only using Herpes 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 been demonstrated using a variety of replication competent and replication 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 long-term gene expression from latent virus genomes needs to be defined in different cell types in vivo.