Subscribe to RSS
DOI: 10.1055/s-0039-3402260
A dual role for hepatocyte-intrinsic canonical NF-κB signaling in virus control
Publication History
Publication Date:
03 January 2020 (online)
Background & Aims:
Hepatic innate immune control of viral infections has largely been attributed to Kupffer cells, the liver macrophages. However, also hepatocytes, the parenchymal cells of the liver, possess potent immunological functions in addition to their known metabolic functions. Owing to their abundance in the liver and known functions, we aimed to investigate the direct anti-viral mechanisms employed by hepatocytes.
Methods:
Using lymphocytic choriomeningitis virus (LCMV) as a model of liver infection, we first assessed the role of myeloid cells by depletion prior to infection. We investigated the role of hepatocyte-intrinsic innate immune signaling by infecting mice lacking canonical NF-κB signaling (IKKβΔHep) specifically in hepatocytes. In addition, mice lacking hepatocyte-specific interferon-α/β signaling-(IFNARΔHep), or interferon-α/β signaling in myeloid cells-(IFNARΔMyel) were infected with LCMV.
Results:
Here, we demonstrate that LCMV activates NF-κB signaling in hepatocytes. LCMV-triggered NF-κB activation in hepatocytes did not depend on Kupffer cells or TNFR1 signaling. LCMV-infected IKKβΔHep livers displayed strongly elevated viral titers due to LCMV accumulation within hepatocytes, reduced interferon-stimulated gene (ISG) expression, delayed intrahepatic immune cell influx and delayed intrahepatic LCMV-specific CD8+ T-cell responses. Notably, viral clearance and ISG expression were also reduced in LCMV-infected primary hepatocytes lacking IKKβ, demonstrating a hepatocyte-intrinsic effect. Similar to livers of IKKβΔHep mice, enhanced hepatocytic LCMV accumulation was observed in livers of IFNARΔHep, whereas IFNARΔMyel mice were able to control LCMV-infection. Hepatocytic NF-κB signaling was also required for efficient ISG induction and interferonα/β-mediated inhibition of HBV replication in vitro, in HBV- or HDV-infected HepaRGs.
Conclusions:
Together, these data show that hepatocyte-intrinsic NF-κB is a vital amplifier of interferonα/β signaling pivotal for early, strong ISG responses, influx of immune cells and hepatic viral clearance.
#