[Establishment of reverse genetics system for H5N1 subtype AI]

Area of Science:

• Virology
• Molecular Biology
• Immunology

Context:

• The H5N1 influenza virus poses a significant threat to avian and human health.
• Developing effective vaccine candidates and understanding viral pathogenesis are crucial for H5N1 control.
• Reverse genetics systems are essential tools for influenza virus research.

Purpose:

• To establish an eight-plasmid reverse genetics system for the H5N1 influenza virus A/Duck/Shandong/093/2004 (A/SD/04) strain.
• To generate reassortant H5N1 viruses with defined genetic compositions.
• To investigate the influence of internal gene reassortment on viral characteristics and virulence.

Summary:

• An eight-plasmid system was constructed for the A/SD/04 H5N1 strain, enabling the generation of eight reassortant viruses.
• These reassortants shared the same HA and NA genes but had varying internal genes, exhibiting similar viral titers and replication in embryonated eggs.
• However, the reassortants showed differential virulence in chickens, indicating that internal genes impact pathogenicity but not replication in eggs.

Impact:

• The established rescue system provides a foundation for further research into H5N1 gene functions.
• The findings suggest that A/SD/04 can serve as a backbone for developing H5 AIV vaccine candidates by replacing PR8.
• This research contributes to the development of novel strategies for H5N1 influenza virus control and prevention.