PRRSV-2 nsp2 Ignites NLRP3 inflammasome through IKKβ-dependent dispersed trans-Golgi network translocation

Area of Science:

• Immunology
• Virology
• Molecular Biology

Background:

• The NLRP3 inflammasome is a key innate immune sensor.
• Dysregulated NLRP3 activation contributes to viral pathogenesis.
• Porcine reproductive and respiratory syndrome virus type 2 (PRRSV-2) causes severe respiratory disease.

Purpose of the Study:

• To elucidate the mechanism by which PRRSV-2 activates the NLRP3 inflammasome.
• To identify viral factors responsible for PRRSV-2-induced hyperinflammation.

Main Methods:

• PRRSV-2 infection models in vitro and in vivo.
• Western blotting and immunofluorescence assays to detect protein interactions and localization.
• Cytokine profiling to assess inflammatory responses.

Main Results:

• PRRSV-2 non-structural protein 2 (nsp2) was identified as a key activator of the NLRP3 inflammasome.
• PRRSV-2 nsp2 interacts with the NACHT domain of NLRP3, promoting its translocation to the trans-Golgi network (TGN).
• This process leads to ASC polymerization, NLRP3 inflammasome activation, and subsequent cytokine release, contributing to hyperinflammation.

Conclusions:

• PRRSV-2 nsp2 activates the NLRP3 inflammasome through a novel mechanism involving IKKβ-dependent translocation to the TGN.
• This pathway is crucial for PRRSV-2 pathogenesis and hyperinflammation.
• The findings provide insights into PRRSV-2 pathogenesis and potential therapeutic strategies targeting the NLRP3 inflammasome.