title: Meganucleases and other tools for targeted genome engineering: perspectives and challenges for gene therapy.
abstract: The importance of safer approaches for gene therapy has been underscored by a series of severe adverse events (SAEs) observed in patients involved in clinical trials for Severe Combined Immune Deficiency Disease (SCID) and Chromic Granulomatous Disease (CGD). While a new generation of viral vectors is in the process of replacing the classical gamma-retrovirus-based approach, a number of strategies have emerged based on non-viral vectorization and/or targeted insertion aimed at achieving safer gene transfer. Currently, these methods display lower efficacies than viral transduction although many of them can yield more than 1% of engineered cells in vitro. Nuclease-based approaches, wherein an endonuclease is used to trigger site-specific genome editing, can significantly increase the percentage of targeted cells. These methods therefore provide a real alternative to classical gene transfer as well as gene editing. However, the first endonuclease to be in clinic today is not used for gene transfer, but to inactivate a gene (CCR5) required for HIV infection. Here, we review these alternative approaches, with a special emphasis on meganucleases, a family of naturally occurring rare-cutting endonucleases, and speculate on their current and future potential.
authors.affiliation: Cellectis Genome Surgery, 102 Avenue Gaston Roussel, Romainville Cedex, France.
authors.forename: George
authors.initials: G
authors.lastname: Silva
authors.forename: Laurent
authors.initials: L
authors.lastname: Poirot
authors.forename: Roman
authors.initials: R
authors.lastname: Galetto
authors.forename: Julianne
authors.initials: J
authors.lastname: Smith
authors.forename: Guillermo
authors.initials: G
authors.lastname: Montoya
authors.forename: Philippe
authors.initials: P
authors.lastname: Duchateau
authors.forename: Frédéric
authors.initials: F
authors.lastname: Pâques
mesh_terms: D000818:Animals; D004706:Endodeoxyribonucleases / Q000502:physiology; D004720:Endonucleases / Q000235:genetics*; D015316:Genetic Therapy / Q000009:adverse effects* / Q000639:trends*; D005822:Genetic Vectors; D016678:Genome; D015658:HIV Infections / Q000209:etiology; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D016254:Mutagenesis, Insertional; D019713:Receptors, CCR5 / Q000235:genetics
chemical_list: D019713:Receptors, CCR5; D004706:Endodeoxyribonucleases; D004720:Endonucleases