title: Lentivectors for regulated and reversible cutaneous gene delivery.
abstract: Systemic administration of therapeutic proteins has value in treating a wide variety of disorders, including erythropoietin (Epo)-responsive anemias. Recombinant proteins, however, are costly and require repeated injections, while gene delivery approaches have suffered from inefficiency and difficulties with regulation. The skin effectively delivers polypeptides to the circulation, and improved approaches would support sustainable, topically regulated protein expression after a single vector injection. Toward this goal, we generated lentivectors in which both gene delivery and persistence in skin are regulated by administration of distinct steroid ligands. Following a single injection of regulated lentivector into human skin regenerated on immunodeficient mice, topical glucocorticoid ligands regulated Epo levels and hematocrit over time. Abrogation of gene delivery was achieved by both glucocorticoid cessation and proviral excision via a 4-hydroxytamoxifen-inducible Cre recombinase. These findings establish an approach to durable, topically controlled systemic delivery of therapeutic proteins from human skin tissue.
authors.affiliation: VA Alto Healthcare System, Palo Alto, California 94025, USA.
authors.forename: Zurab
authors.initials: Z
authors.lastname: Siprashvili
authors.forename: Paul A
authors.initials: PA
authors.lastname: Khavari
mesh_terms: D000279:Administration, Cutaneous; D000740:Anemia / Q000628:therapy; D000818:Animals; D002460:Cell Line; D002990:Clobetasol / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D004921:Erythropoietin / Q000235:genetics; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage*; D005938:Glucocorticoids / Q000494:pharmacology; D006801:Humans; D019426:Integrases / Q000235:genetics / Q000378:metabolism; D016086:Lentivirus / Q000235:genetics*; D051379:Mice; D020218:Response Elements / Q000235:genetics; D013629:Tamoxifen / Q000031:analogs & derivatives* / Q000494:pharmacology; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D005938:Glucocorticoids; D014764:Viral Proteins; D013629:Tamoxifen; D004921:Erythropoietin; C016601:afimoxifene; D003907:Dexamethasone; D002990:Clobetasol; C045073:Cre recombinase; D019426:Integrases