IFN-γ siRNA Effectively Knocked Down IFN-γ Gene Expression and Reduced Cytokine Secretion in Peripheral Blood Mononuclear Cells of Patients with Autoimmune Hepatitis

Background: Autoimmune hepatitis (AIH) is an inflammatory liver disorder that commonly affects women. The T cells and one of their major products, IFN-γ, are critically involved in the pathogenesis of AIH. Therefore, targeting of IFN-γ can probably be therapeutically useful while avoiding the long-term side effects of conventional immunosuppressive therapy. RNA interference, provides an ideal way to achieve this purpose. Thus, the aim of this study was to investigate the effect of IFN-γ-siRNA on IFN-γ expression in human peripheral blood mononuclear cells of patients with AIH. Methods: In order to evaluate the anti-cytokine therapy with IFN-γ-siRNA, the PBMCs of AIH patients were cultured and transfected with IFN-γ-siRNA. After validation of transfection efficiency, the effects of gene silencing were tested with quantitative real-time polymerase chain reaction and intracellular flow cytometry. Results: The efficiently transfected cells, with the targeted IFN-γ-siRNA, without affecting cell viability showed a strong gene knockdown. The IFN-γ gene expression was significantly decreased in transfected cells (P < 0.05). Moreover, flow cytometric analysis confirmed the decrease of the intracellular IFN-γ protein level after siRNA transfection. Conclusions: Collectively, the results of the present study suggested that modifying the cytokine profile without inducing apoptosis using siRNA-based technology could be a promising tool for therapeutic intervention in T cells-dependent inflammatory diseases like AIH.