Inflammasome-induced extracellular vesicles harbour distinct RNA signatures and alter bystander macrophage responses

Area of Science:

• Immunology
• Cell Biology
• Molecular Medicine

Background:

• Inflammasomes mediate inflammation and immunity, crucial for microbial defense and tissue repair.
• Chronic inflammasome activation drives non-resolving inflammation and immunopathology.
• Inflammasome-activated cells release extracellular vesicles (EVs) with pro-inflammatory cytokines.

Purpose of the Study:

• To investigate the RNA content and function of EVs released from inflammasome-activated macrophages.
• To determine if EVs can serve as biomarkers for inflammasome activation.
• To explore the role of EVs in modulating bystander cell activation and inflammation.

Main Methods:

• Systems analysis of RNA content in two classes of EVs.
• Characterization of EV-associated molecules, including interferon beta (IFNβ).
• Assessing the functional impact of EVs on bystander cells and inflammasome responses.

Main Results:

• EVs from inflammasome-activated macrophages exhibit a specific RNA signature.
• These EVs contain and transfer functional interferon beta (IFNβ) to bystander cells.
• EV-associated IFNβ induces an interferon signature in bystander cells and dampens NLRP3 inflammasome activation.

Conclusions:

• Inflammasome-induced EVs can serve as biomarkers for inflammasome pathway activation.
• EV-associated IFNβ plays a regulatory role, preventing systemic hyper-inflammatory states.
• EVs may act as a negative feedback mechanism to restrict excessive inflammasome responses.