Hepatitis C virus (HCV) evades innate immune detection primarily by which mechanism at the level of interferon signaling?

• A HCV core protein sequesters IRF-3 in the cytoplasm
• B HCV NS5B binds and inactivates STAT1
• C HCV NS3/4A protease cleaves TRIF and MAVS (IPS-1), disrupting TLR3 and RIG-I signaling pathways ✓
• D HCV E1 glycoprotein blocks MHC class I antigen presentation

Explanation

HCV NS3/4A serine protease cleaves two critical adaptor proteins in innate antiviral signaling: MAVS/IPS-1 (mitochondrial antiviral-signaling protein, required for RIG-I/MDA-5 pathway) and TRIF (adaptor for TLR3). By cleaving these adaptors, HCV prevents IRF-3 phosphorylation and nuclear translocation, blocking type I interferon (IFN-α/β) production and establishing persistent infection. This is the primary immune evasion mechanism and was targeted therapeutically — protease inhibitors like telaprevir/boceprevir were first-generation DAAs, later superseded by NS5A/NS5B inhibitors.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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