title: Clonal evidence for the transduction of CD34+ cells with lymphomyeloid differentiation potential and self-renewal capacity in the SCID-X1 gene therapy trial.
abstract: Immune function has been restored in 9 of 10 children with X-linked severe combined immunodeficiency by gamma c gene transfer in CD34+ cells. The distribution of both T-cell receptor (TCR) V beta family usage and TCR V beta complementarity-determining region 3 (CDR3) length revealed a broadly diversified T-cell repertoire. Retroviral integration site analysis in T cells demonstrated a high number of distinct insertion sites, indicating polyclonality of genetically corrected cell clones, in all patients. Detection of gamma c transgene expression on patients' mature myeloid cells has prompted us to investigate the nature of the most immature transduced hematopoietic precursor cells. Insertion sites shared by T and B lymphocytes as well as highly purified granulocytes and monocytes demonstrate the correction of common multipotent progenitor cells. Moreover, our data show that differentiated leukocytes share the same exact insertion sites with CD34+ cells that we obtained 8 months later and that were able to generate long-term culture-initiating cells (LTC-ICs). This finding demonstrates the initial transduction of very primitive multipotent progenitor cells with self-renewal capacity. These results provide a first evidence in the setting of a clinical trial that CD34+ cells maintain both lymphomyeloid potential as well as self-renewal capacity after ex vivo manipulation.
authors.affiliation: Department of Internal Medicine, University of Freiburg, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Schmidt
authors.forename: Salima
authors.initials: S
authors.lastname: Hacein-Bey-Abina
authors.forename: Manuela
authors.initials: M
authors.lastname: Wissler
authors.forename: Frederique
authors.initials: F
authors.lastname: Carlier
authors.forename: Annick
authors.initials: A
authors.lastname: Lim
authors.forename: Claudia
authors.initials: C
authors.lastname: Prinz
authors.forename: Hanno
authors.initials: H
authors.lastname: Glimm
authors.forename: Isabelle
authors.initials: I
authors.lastname: Andre-Schmutz
authors.forename: Christophe
authors.initials: C
authors.lastname: Hue
authors.forename: Alexandrine
authors.initials: A
authors.lastname: Garrigue
authors.forename: Francoise
authors.initials: F
authors.lastname: Le Deist
authors.forename: Chantal
authors.initials: C
authors.lastname: Lagresle
authors.forename: Alain
authors.initials: A
authors.lastname: Fischer
authors.forename: Marina
authors.initials: M
authors.lastname: Cavazzana-Calvo
authors.forename: Christof
authors.initials: C
authors.lastname: von Kalle
mesh_terms: D018952:Antigens, CD34 / Q000276:immunology; D002454:Cell Differentiation / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D002999:Clone Cells; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D006098:Granulocytes / Q000166:cytology / Q000502:physiology; D006410:Hematopoiesis; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000276:immunology; D006801:Humans; D012190:Retroviridae / Q000235:genetics; D016511:Severe Combined Immunodeficiency / Q000235:genetics / Q000276:immunology / Q000628:therapy*; D013601:T-Lymphocytes / Q000166:cytology* / Q000502:physiology; D014161:Transduction, Genetic
chemical_list: D018952:Antigens, CD34