title: In vivo delivery of human acid ceramidase via cord blood transplantation and direct injection of lentivirus as novel treatment approaches for Farber disease.
abstract: Farber disease is a rare lysosomal storage disorder (LSD) caused by a deficiency of acid ceramidase (AC) activity and subsequent accumulation of ceramide. Currently, there is no treatment for Farber disease beyond palliative care and most patients succumb to the disorder at a very young age. Previously, our group showed that gene therapy using oncoretroviral vectors (RV) could restore enzyme activity in Farber patient cells. The studies described here employ novel RV and lentiviral (LV) vectors that engineer co-expression of AC and a cell surface marking transgene product, human CD25 (huCD25). Transduction of Farber patient fibroblasts and B cells with these vectors resulted in overexpression of AC and led to a 90% and 50% reduction in the accumulation of ceramide, respectively. Vectors were also evaluated in human hematopoietic stem/progenitor cells (HSPCs) and by direct in vivo delivery in mouse models. In a xenotransplantation model using NOD/SCID mice, we found that transduced CD34(+) cells could repopulate irradiated recipient animals, as measured by CD25 expression. When virus was injected intravenously into mice, soluble CD25 was detected in the plasma and increased AC activity was present in the liver up to 14 weeks post-injection. These findings suggest that vector and transgene expression can persist long-term and offer the potential of a lasting cure. To our knowledge, this is the first report of in vivo testing of direct gene therapy strategies for Farber disease.
authors.affiliation: Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Shobha
authors.initials: S
authors.lastname: Ramsubir
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nonaka
authors.forename: Carmen Bedia
authors.initials: CB
authors.lastname: Girbés
authors.forename: Stéphane
authors.initials: S
authors.lastname: Carpentier
authors.forename: Thierry
authors.initials: T
authors.lastname: Levade
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Medin
mesh_terms: D055573:Acid Ceramidase / Q000235:genetics / Q000378:metabolism / Q000627:therapeutic use*; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D002518:Ceramides / Q000378:metabolism; D036101:Cord Blood Stem Cell Transplantation / Q000379:methods*; D055577:Farber Lipogranulomatosis / Q000235:genetics* / Q000628:therapy*; D005347:Fibroblasts / Q000378:metabolism / Q000821:virology; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000821:virology; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000235:genetics / Q000378:metabolism; D016086:Lentivirus / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D016513:Mice, SCID
chemical_list: D002518:Ceramides; D053645:Interleukin-2 Receptor alpha Subunit; D055573:Acid Ceramidase