Reverse genetics for crimean-congo hemorrhagic fever virus

Area of Science:

• Virology
• Molecular Biology
• Public Health

Background:

• Crimean-Congo hemorrhagic fever (CCHF) virus is a significant global health threat due to its wide distribution and high mortality rate.
• CCHF virus belongs to the genus Nairovirus within the family Bunyaviridae.
• Developing tools to study CCHF virus is crucial for understanding its pathogenesis and creating countermeasures.

Purpose of the Study:

• To establish a functional reverse genetics system for CCHF virus.
• To enable the generation of recombinant CCHF viruses for further research.
• To explore the potential of the RNA polymerase I (pol I) system for Bunyaviridae research.

Main Methods:

• Utilized an RNA polymerase I (pol I) system to create artificial viral RNA genome segments (minigenomes) for CCHF virus.
• Incorporated reporter genes into minigenomes in both antisense and sense orientations, flanked by CCHF virus S segment noncoding regions.
• Transfected minigenomes into eukaryotic cells, followed by superinfection with CCHF virus to assess encapsidation, transcription, and replication.

Main Results:

• Demonstrated reporter gene expression in eukaryotic cells, confirming the functionality of the pol I-derived minigenomes.
• Confirmed encapsidation, transcription, and replication of minigenomes within infected cells.
• Showcased the generation of infectious recombinant CCHF viruses through the transfer of reporter gene activity to new cells.

Conclusions:

• The established reverse genetics system provides a powerful tool for studying Nairovirus biology.
• This technology facilitates the development of novel therapeutic and prophylactic strategies against CCHF.
• The study highlights the utility of the human pol I system for reverse genetics in Bunyaviridae, including primate-restricted viruses.