title: Development of novel efficient SIN vectors with improved safety features for Wiskott-Aldrich syndrome stem cell based gene therapy.
abstract: Gene therapy is a promising therapeutic approach to treat primary immunodeficiencies. Indeed, the clinical trial for the Wiskott-Aldrich Syndrome (WAS) that is currently ongoing at the Hannover Medical School (Germany) has recently reported the correction of all affected cell lineages of the hematopoietic system in the first treated patients. However, an extensive study of the clonal inventory of those patients reveals that LMO2, CCND2 and MDS1/EVI1 were preferentially prevalent. Moreover, a first leukemia case was observed in this study, thus reinforcing the need of developing safer vectors for gene transfer into HSC in general. Here we present a novel self-inactivating (SIN) vector for the gene therapy of WAS that combines improved safety features. We used the elongation factor 1 alpha (EFS) promoter, which has been extensively evaluated in terms of safety profile, to drive a codon-optimized human WASP cDNA. To test vector performance in a more clinically relevant setting, we transduced murine HSPC as well as human CD34+ cells and also analyzed vector efficacy in their differentiated myeloid progeny. Our results show that our novel vector generates comparable WAS protein levels and is as effective as the clinically used LTR-driven vector. Therefore, the described SIN vectors appear to be good candidates for potential use in a safer new gene therapy protocol for WAS, with decreased risk of insertional mutagenesis.
authors.affiliation: Department of Pediatric Hematology/Oncology, Hannover Medical School, Hannover, Germany.
authors.forename: Inés
authors.initials: I
authors.lastname: Avedillo Díez
authors.forename: Daniela
authors.initials: D
authors.lastname: Zychlinski
authors.forename: Emanuele G
authors.initials: EG
authors.lastname: Coci
authors.forename: Melanie
authors.initials: M
authors.lastname: Galla
authors.forename: Ute
authors.initials: U
authors.lastname: Modlich
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Dewey
authors.forename: Adrian
authors.initials: A
authors.lastname: Schwarzer
authors.forename: Tobias
authors.initials: T
authors.lastname: Maetzig
authors.forename: Nonsikelelo
authors.initials: N
authors.lastname: Mpofu
authors.forename: Elmar
authors.initials: E
authors.lastname: Jaeckel
authors.forename: Kaan
authors.initials: K
authors.lastname: Boztug
authors.forename: Christopher
authors.initials: C
authors.lastname: Baum
authors.forename: Christoph
authors.initials: C
authors.lastname: Klein
authors.forename: Axel
authors.initials: A
authors.lastname: Schambach
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D002454:Cell Differentiation; D002460:Cell Line; D003131:Combined Modality Therapy / Q000009:adverse effects; D005240:Feasibility Studies; D015967:Gene Expression Regulation, Viral; D015316:Genetic Therapy / Q000009:adverse effects; D005822:Genetic Vectors / Q000009:adverse effects* / Q000235:genetics / Q000378:metabolism; D006412:Hematopoietic Stem Cells / Q000378:metabolism* / Q000821:virology; D017919:Hepatitis B Virus, Woodchuck / Q000235:genetics / Q000378:metabolism; D006801:Humans; D016086:Lentivirus / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D022423:Myeloid Cells / Q000166:cytology / Q000378:metabolism / Q000473:pathology / Q000821:virology; D020648:Peptide Elongation Factor 1 / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D033581:Stem Cell Transplantation / Q000009:adverse effects; D014923:Wiskott-Aldrich Syndrome / Q000097:blood / Q000378:metabolism* / Q000628:therapy; D051316:Wiskott-Aldrich Syndrome Protein / Q000235:genetics / Q000378:metabolism* / Q000627:therapeutic use
chemical_list: D018952:Antigens, CD34; D020648:Peptide Elongation Factor 1; D012333:RNA, Messenger; C495767:WAS protein, human; D051316:Wiskott-Aldrich Syndrome Protein