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Frecha C.,French Institute of Health and Medical Research | Frecha C.,Ecole Normale Superieure de Lyon | Frecha C.,University of Lyon | Costa C.,French Institute of Health and Medical Research | And 17 more authors.
Blood | Year: 2012

In vivo lentiviral vector (LV)-mediated gene delivery would represent a great step forward in the field of gene therapy. Therefore, we have engineered a novel LV displaying SCF and a mutant cat endogenous retroviral glycoprotein, RDTR. These RDTR/SCF-LVs outperformed RDTR-LVs for transduction of human CD34 + cells (hCD34 +). For in vivo gene therapy, these novel RDTR/SCF-displaying LVs can distinguish between the target hCD34 + cells of interest and nontarget cells. Indeed, they selectively targeted transduction to 30%-40% of the hCD34 + cells in cord blood mononuclear cells and in the unfractionated BM of healthy and Fanconi anemia donors, resulting in the correction of CD34 + cells in the patients. Moreover, RDTR/SCF-LVs targeted transduction to CD34 + cells with 95-fold selectivity compared with T cells in total cord blood. Remarkably, in vivo injection of the RDTR/SCF-LVs into the BM cavity of humanized mice resulted in the highly selective transduction of candidate hCD34 +Lin - HSCs. In conclusion, this new LV will facilitate HSC-based gene therapy by directly targeting these primitive cells in BM aspirates or total cord blood. Most importantly, in the future, RDTR/SCF-LVs might completely obviate ex vivo handling and simplify gene therapy for many hematopoietic defects because of their applicability to direct in vivo inoculation. © 2012 by The American Society of Hematology.

Aufenvenne K.,University of Munster | Larcher F.,Centro Of Investigaciones Energeticas | Hausser I.,University of Heidelberg | Duarte B.,Centro Of Investigaciones Energeticas | And 6 more authors.
American Journal of Human Genetics | Year: 2013

Transglutaminase-1 (TG1)-deficient autosomal-recessive congenital ichthyosis (ARCI) is a rare and severe genetic skin disease caused by mutations in TGM1. It is characterized by collodion babies at birth, dramatically increased transepidermal water loss (TEWL), and lifelong pronounced scaling. The disease has a tremendous burden, including the problem of stigmatization. Currently, no therapy targeting the molecular cause is available, and the therapeutic situation is deplorable. In this study, we developed the basis for a causative therapy aiming at the delivery of the enzyme to the inner site of the keratinocytes' plasma membrane. We prepared sterically stabilized liposomes with encapsulated recombinant human TG1 (rhTG1) and equipped with a highly cationic lipopeptide vector to mediate cellular uptake. The liposomes overcame the problems of insufficient cutaneous delivery and membrane penetration and provided excellent availability and activity of rhTG1 in primary keratinocytes. To demonstrate the general feasibility of this therapeutic approach in a humanized context, we used a skin-humanized mouse model. Treatment with rhTG1 liposomes resulted in considerable improvement of the ichthyosis phenotype and in normalization of the regenerated ARCI skin: in situ monitoring showed a restoration of TG1 activity, and cholesterol clefts vanished ultrastructurally. Measurement of TEWL revealed a restoration of epidermal barrier function. We regard this aspect as a major advance over available nonspecific approaches making use of, for example, retinoid creams. We conclude that this topical approach is a promising strategy for restoring epidermal integrity and barrier function and provides a causal cure for individuals with TG1 deficiency. © 2013 The American Society of Human Genetics. All rights reserved.

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