Exosomal MicroRNA-155 Inhibits Enterovirus A71 Infection by Targeting PICALM

Area of Science:

• Virology
• Molecular Biology
• Immunology

Background:

• Enterovirus A71 (EV-A71) causes hand, foot, and mouth disease (HFMD) with potential neurological complications.
• Exosomes mediate intercellular communication and can transfer microRNAs (miRNAs) to modulate cellular responses during viral infections.
• The specific role of exosomal miRNAs in regulating EV-A71 infection remains largely unknown.

Purpose of the Study:

• To investigate the role of exosomal miRNAs in EV-A71 infection.
• To identify specific exosomal miRNAs that modulate EV-A71 replication and pathogenesis.
• To elucidate the molecular mechanism by which exosomal miRNAs regulate EV-A71 infection.

Main Methods:

• Utilized an exosomal miRNA chip to profile miRNA expression in exosomes after EV-A71 infection.
• Investigated the inhibitory effect of exosomal microRNA-155 (miR-155) on EV-A71 infection in recipient cells.
• Validated the target gene of exosomal miR-155, phosphatidylinositol clathrin assembly protein (PICALM).
• Assessed the therapeutic potential of exosomal miR-155 in vivo.
• Measured miR-155 levels in throat swabs from EV-A71-infected patients and healthy individuals.

Main Results:

• EV-A71 infection markedly enriched microRNA-155 (miR-155) in exosomes.
• Exosomal miR-155 demonstrated potent inhibition of EV-A71 infection by targeting PICALM in recipient cells.
• Administration of exosomal miR-155 significantly reduced EV-A71 infection severity in vivo.
• Elevated miR-155 levels were observed in throat swabs of EV-A71-infected patients compared to healthy controls.

Conclusions:

• Exosomal miR-155 plays a crucial role in host-pathogen interactions during EV-A71 infection.
• Exosomal miR-155 mediates antiviral activity by repressing PICALM expression in recipient cells.
• These findings provide novel insights into the regulatory mechanisms of EV-A71 infection and suggest exosomal miR-155 as a potential therapeutic agent.