Enhancing the potency of in vivo lentiviral vector mediated gene therapy to hepatocytes
Cesare Canepari, Michela Milani, Chiara Simoni, Francesco Starinieri, Monica Volpin, Anna Fabiano, Mauro Biffi, Fabio Russo, Rossana Norata, Martina Rocchi, Chiara Brombin, Federica Cugnata, Eugenio Montini, Francesca Sanvito, Markus Grompe, Alessio Cantore
Abstract
In vivo gene therapy to the liver using lentiviral vectors (LV) may represent a one-and-done therapeutic approach for monogenic diseases. Increasing LV gene therapy potency is crucial for reducing the effective doses, thus alleviating dose-dependent toxicities and facilitating manufacturing. LV-mediated liver transduction may be enhanced by positively selecting LV-transduced hepatocytes after treatment (a posteriori) or by augmenting the initial fraction of LV-targeted hepatocytes (a priori). We show here that the a posteriori enhancement increased transgene output without expansion of hepatocytes bearing LV genomic integrations near cancer genes, in mouse models of hemophilia, an inherited coagulation disorder. Furthermore, we enhanced hepatocyte transduction a priori in mice by transiently inhibiting antiviral pathways and/or through a fasting regimen. The most promising transduction-enhancer combination synergized with phagocytosis-shielded LV, resulting in a remarkable 40-fold increase in transgene output. Overall, our work highlights the potential of minimally invasive, cost-effective treatments capable of improving the potency of in vivo LV gene therapy to hepatocytes, in order to expand its applicability and ease clinical translation. Lentiviral vectors are promising gene delivery vehicles to target hepatocytes in vivo, but restriction factors limit their efficiency. Here, the authors counteract many of these restrictions, amplifying lentiviral gene transfer into hepatocytes, strengthening its translational potential.