POTENTIAL USE OF HERPES-SIMPLEX VIRUS (HSV) VECTORS FOR GENE-THERAPY OF NEUROLOGICAL DISORDERS

Advances in molecular biology and virus genetics have allowed the poss ibility of gene therapy using viral vectors for a variety of neurologi cal diseases in which the genetic or biochemical basis is understood. A number of such vectors have now been constructed, including those de rived from herpes simplex virus (HSV), adenovirus, retrovirus and aden o-associated virus, and used in preliminary in vitro experiments and i n, animal models. It is possible to package a foreign gene into such a vector which can then be targeted to specific regions of the nervous system. HSV is particularly appropriate for delivering genes to neuron s in view of its ability to establish latent infection in these cells. Viral vectors have the potential to be used to treat such neurologica l conditions as malignant gliomas, Parkinson's disease, known single g ene disorders and cerebral ischaemia. However the technical problems w hich will need to be overcome are formidable and will not be easily so lved. The problems include the efficient delivery of the vector to tar get cells, the maintenance and control of foreign gene expression, and the control of unwanted host immune responses.