ERA-Net E-Rare

This project aims to further improve the technology of gene therapy for thalassemia as well as to prepare the ground for future clinical trials in the gene therapy field. Gene therapy utilizing lentiviral vectors (LVs) is considered as a real therapeutic alternative for many hemopoietic inherited diseases, such as beta-thalassemia. A major limitation of current LVs is their inability to govern efficient gene transfer into quiescent cells, such as human CD34+ cells that reside in the Go phase of the cell cycle. Additional problems of these vectors are the low titers observed due to regulatory elements of the beta-globin locus, such as the LCR, used in order to improve the transgene’s expression and reduce silencing, as well as the toxicity posed on CD34+ cells due to usage of VSV-G as an envelope protein. These facts hamper their application for gene therapy of hematopoietic cells. Thus, the major current drawbacks affecting therapeutic efficacy, include 1) insufficient transduction efficiency of the target hemopoietic stem cells, 2) inconsistent expression of the transgene and lack of long term expression due to silencing and 3) putative aberrant expression near integration sites raising safety issues. To this end, the current proposal aims to address comprehensively specific issues of the globin gene therapy, by the 1) improvement of current vector technology, 2) development of novel strategies for cell targeting and finally 3) establishing an extensive genotoxic study for the generation of a cell model that will permit and predict patient safety for future clinical trials.