A Genome-Wide RNA Interference Screen Identifies a Role for Wnt/β-Catenin Signaling during Rift Valley Fever Virus...

Area of Science:

• Virology
• Molecular Biology
• Cell Biology

Background:

• Rift Valley fever virus (RVFV) is a significant arbovirus causing severe illness in humans and livestock.
• Bunyaviruses, including RVFV, pose a threat due to their potential for widespread outbreaks and lack of specific treatments.
• Understanding host-pathogen interactions is crucial for developing effective antiviral strategies.

Purpose of the Study:

• To identify host factors essential for bunyavirus replication using genome-wide screening.
• To investigate the role of the Wnt signaling pathway in RVFV infection.
• To determine if Wnt signaling is a conserved mechanism in bunyavirus replication.

Main Methods:

• Genome-wide RNA interference (RNAi) screening to identify host genes affecting RVFV infection.
• Functional clustering of gene hits to identify enriched biological pathways.
• Experimental validation of Wnt signaling's role using gene knockdown, pathway activation, and inhibitor studies.
• Testing the conserved role of Wnt signaling with other bunyaviruses like La Crosse virus.

Main Results:

• Genome-wide RNAi screening identified 381 host genes that, when reduced, decreased RVFV infection.
• The Wnt signaling pathway was significantly enriched among the identified host factors.
• RVFV infection activated Wnt signaling, and its replication was enhanced by preactivated Wnt signaling.
• Knockdown of β-catenin or inhibition of Wnt signaling significantly reduced RVFV infection.
• Similar results were observed with other bunyaviruses, indicating a conserved role for Wnt signaling.

Conclusions:

• Bunyaviruses, including RVFV, exploit the host's Wnt signaling pathway for efficient replication.
• Wnt signaling likely promotes optimal cell cycle conditions conducive to viral replication.
• Targeting the Wnt pathway offers a potential host-directed therapeutic strategy against bunyavirus infections.
• These findings provide insights into conserved bunyaviral replication mechanisms and avenues for countermeasure development.