Cell death-inducing DFFA-like effector b is required for hepatitis C virus entry into hepatocytes

Area of Science:

• Hepatology
• Virology
• Stem Cell Biology

Background:

• The molecular mechanisms behind hepatitis C virus (HCV) liver tropism are not fully understood.
• Hepatocyte-like cells (HLCs) derived from stem cells offer a model for studying HCV infection and liver development.
• Previous work identified a critical transition stage for HCV permissiveness in HLCs.

Purpose of the Study:

• To investigate the role of a liver-specific protein, cell death-inducing DFFA-like effector b (CIDEB), in HCV infection.
• To determine the specific step in the HCV life cycle where CIDEB function is required.
• To explore CIDEB's potential role in mediating viral entry and membrane fusion.

Main Methods:

• Suppression of CIDEB expression in stem cell-derived HLCs.
• Hepatocyte function assays and HCV infection experiments.
• Cell-based assays to analyze the HCV life cycle and CIDEB's role in viral entry.

Main Results:

• CIDEB is an essential cofactor for HCV entry into hepatocytes.
• Genetic interference with CIDEB renders HLCs resistant to HCV infection.
• CIDEB functions in a late stage of HCV entry, potentially facilitating membrane fusion.
• CIDEB's role in HCV entry is independent of known HCV receptors.
• HCV infection downregulates CIDEB protein via a posttranscriptional mechanism.

Conclusions:

• CIDEB is a critical host factor mediating HCV entry into hepatocytes.
• CIDEB's function in viral entry, particularly membrane fusion, presents a novel target for antiviral strategies.
• The interaction between CIDEB and HCV opens new research avenues into lipid droplets and viral entry mechanisms.