Improving Safety of Lentiviral Gene Transfer

Lentiviral vector (LV)-mediated gene transfer has an excellent therapeutic potential as demonstrated in pre-clinical studies and recent clinical trials. We previously demonstrated that advanced-generation Self-inactivating (SIN) LVs are associated to a lower genotoxic risk when compared to the conventionally used retroviral vectors. However, LV integration into the genome could still affect the function of cellular genes found at or near the insertion site, with deleterious consequences. Thus, a deeper evaluation of their residual genotoxicity is required. In the first aim of this project, we will stringently and comparatively assess the potential toxicity of different SIN LVs using sensitive in vivo assays. With these assays we will test if addition of insulator elements within SIN LV can reduce vector genotoxicity induced by enhancer-mediated activation. As second aim, we will address the impact of LV integrations on the splicing of the targeted genes and we will improve vector design to reduce its splicing interfering potential. Finally, by high throughput monitoring of the LV integrations in preclinical and clinical samples over the time, we will gain functional insights into the safety of SINLV.