Modulation of calcium signaling pathway by hepatitis C virus core protein stimulates NLRP3 inflammasome activation

Area of Science:

• Immunology
• Virology
• Hepatology

Background:

• Hepatitis C virus (HCV) infection causes liver inflammation and disease.
• HCV activates the NLRP3 inflammasome and interleukin-1β (IL-1β) production in Kupffer cells, driving hepatic inflammation.

Purpose of the Study:

• To define the specific HCV component and cellular mechanisms responsible for NLRP3 inflammasome activation.
• To investigate HCV's activation of the NLRP3 inflammasome signaling cascade in models of hepatic macrophages.

Main Methods:

• Utilized primary human monocyte-derived macrophages and THP-1 cell models.
• Examined inflammasome activation in response to HCV and soluble HCV core protein.

Main Results:

• Identified the HCV core protein as a critical virion-specific factor for inflammasome activation.
• Demonstrated that the core protein alone is sufficient to induce IL-1β production in macrophages.
• Showed that core protein-induced NLRP3 inflammasome activation requires calcium mobilization and phospholipase-C activation.

Conclusions:

• The HCV core protein is a direct activator of the NLRP3 inflammasome in hepatic macrophages.
• This study reveals the molecular basis for HCV-driven hepatic inflammasome activation and IL-1β release.