Rotavirus VP3 targets MAVS for degradation to inhibit type III interferon expression in intestinal epithelial cells

Area of Science:

• Virology
• Immunology
• Molecular Biology

Background:

• Rotaviruses (RVs) are a major cause of severe diarrhea in children and mammals.
• RVs employ non-structural protein 1 (NSP1) to evade host interferon (IFN) signaling.
• The role of RV structural proteins in subverting antiviral responses is less understood.

Purpose of the Study:

• To investigate whether RV structural proteins can inhibit host innate immunity.
• To elucidate the mechanism by which RV VP3 interacts with and inhibits MAVS signaling.
• To determine the impact of VP3-mediated MAVS degradation on RV replication and pathogenesis.

Main Methods:

• Investigated the interaction between RV VP3 and MAVS in infected cells.
• Utilized cell-based assays to assess MAVS degradation and IFN-λ production.
• Performed in vivo studies to evaluate the role of VP3 in viral pathogenesis.

Main Results:

• RV structural protein VP3 degrades MAVS, a crucial adaptor protein in RNA sensing pathways.
• VP3 targets a novel SPLTSS motif in MAVS, leading to its proteasomal degradation.
• VP3-mediated MAVS inhibition blocks IFN-λ production, enhances RV replication, and contributes to pathogenesis.
• VP3's inhibitory activity on MAVS is host-range restricted.

Conclusions:

• RV VP3 acts as a viral antagonist of MAVS signaling in mammals.
• VP3-induced MAVS degradation represents a novel mechanism for pathogens to inhibit innate immunity.
• Understanding this interaction provides insights into rotavirus pathogenesis and potential therapeutic targets.