Therapeutic RNA silencing of Cys-X3-Cys chemokine ligand 1 gene prevents mice from adenovirus vector-induced acute liver injury

Gene therapy using adenovirus vectors may induce acute liver injury. Tissue injury induced by an adenovirus is likely associated with elevated expression of the Cys-X3-Cys chemokine ligand 1 (CX(3)CL1)/fractalkine (FKN) protein at the site of inflammation. However, the extent to which the actions of FKN contribute to liver injury remains unclear. We induced acute liver injury in mice by a hydrodynamics-based injection of adenovirus vector, which was confirmed to depend on the presence of natural killer (NK) cells and NK-dependent interferon-gamma (IFN-gamma). When the transferred adenovirus vector was inserted with the FKN gene, the severity of liver injury increased with much more Cys-X3-Cys chemokine receptor 1 (CX(3)CR1)-positive NK cell recruitment into the liver because of exogenous overproduction of FKN protein. Moreover, when production of endogenous FKN protein was silenced by inserting FKN-small interfering RNA into the adenovirus vector or was neutralized by an FKN-specific antibody, the adenovirus-induced acute severe liver injury was notably prevented with much lower hepatic NK cell infiltration and a significant reduction in the serum levels of IFN-gamma. Conclusion: Our findings suggest a strategy to prevent or alleviate adenovirus vector-induced acute liver injury by blocking FKN-CX(3)CR1 interaction in adenovirus vector-based gene therapy.