title: Development and optimization of herpes simplex virus vectors for multiple long-term gene delivery to the peripheral nervous system.
abstract: Herpes simplex virus (HSV) has often been suggested as a suitable vector for gene delivery to the peripheral nervous system as it naturally infects sensory nerve terminals before retrograde transport to the cell body in the spinal ganglia where latency is established. HSV vectors might therefore be particularly appropriate for the study and treatment of chronic pain following vector administration by relatively noninvasive peripheral routes. However parameters allowing safe and efficient gene delivery to spinal ganglia following peripheral vector inoculation, or the long-term expression of delivered genes, have not been comprehensively studied. We have identified combinations of deletions from the HSV genome which allow highly efficient gene delivery to spinal dorsal root ganglia (DRGs) following either footpad or sciatic nerve injection. These vectors have ICP34.5 deleted and have inactivating mutations in vmw65. We also report that peripheral replication is probably necessary for the efficient establishment of latency in vivo, as fully replication-incompetent HSV vectors allow efficient gene expression in DRGs only after peripheral inoculation at a high virus dose. Very low transduction efficiencies are otherwise achieved. In parallel, promoters have been developed that allow the long-term expression of individual or pairs of genes in DRGs by using elements from the latently active region of the virus to confer a long-term activity onto a number of promoters which otherwise function only in the short term. This work further defines elements and mechanisms within the latently active region that are necessary for long-term gene expression and for the first time allows multiple inserted genes to be expressed from HSV vectors during latency.
authors.affiliation: Department of Molecular Pathology, The Windeyer Institute of Medical Sciences, University College London, United Kingdom.
authors.forename: J A
authors.initials: JA
authors.lastname: Palmer
authors.forename: R H
authors.initials: RH
authors.lastname: Branston
authors.forename: C E
authors.initials: CE
authors.lastname: Lilley
authors.forename: M J
authors.initials: MJ
authors.lastname: Robinson
authors.forename: F
authors.initials: F
authors.lastname: Groutsi
authors.forename: J
authors.initials: J
authors.lastname: Smith
authors.forename: D S
authors.initials: DS
authors.lastname: Latchman
authors.forename: R S
authors.initials: RS
authors.lastname: Coffin
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D005727:Ganglia, Spinal / Q000378:metabolism / Q000821:virology; D017353:Gene Deletion; D015967:Gene Expression Regulation, Viral / Q000235:genetics; D018014:Gene Transfer Techniques; D017930:Genes, Reporter / Q000235:genetics; D005818:Genetic Engineering; D005819:Genetic Markers / Q000235:genetics; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics*; D016679:Genome, Viral; D017405:Herpes Simplex Virus Protein Vmw65 / Q000235:genetics; D006614:Hindlimb / Q000502:physiology; D007267:Injections; D009046:Motor Neurons / Q000378:metabolism / Q000821:virology; D017933:Peripheral Nervous System / Q000378:metabolism* / Q000821:virology; D011401:Promoter Regions, Genetic / Q000235:genetics; D012260:Ribonucleases; D012584:Sciatic Nerve / Q000502:physiology; D018139:Simplexvirus / Q000235:genetics* / Q000472:pathogenicity / Q000502:physiology; D013997:Time Factors; D014764:Viral Proteins / Q000235:genetics; D017735:Virus Latency / Q000235:genetics; D014779:Virus Replication / Q000235:genetics
chemical_list: D005819:Genetic Markers; D017405:Herpes Simplex Virus Protein Vmw65; D014764:Viral Proteins; C066469:gamma 34.5 protein, Human herpesvirus 1; C070722:virion host shutoff protein, Simplexvirus; D012260:Ribonucleases