Expression of mouse beta-defensin-3 in MDCK cells and its anti-influenza-virus activity

Area of Science:

• Immunology
• Virology
• Molecular Biology

Background:

• Influenza pandemics pose a significant global health threat.
• Avian flu outbreaks highlight the urgent need for effective influenza control strategies.
• Mammalian beta-defensins (beta-defensins) are key components of innate immunity, known for antimicrobial properties.

Purpose of the Study:

• To investigate the presence and expression of mouse beta-defensin genes (Mbd-1, 2, and 3) in lung and trachea tissues.
• To evaluate the anti-influenza virus activity of mouse beta-defensin 3 (MBD-3) in vitro and in vivo.

Main Methods:

• RT-PCR was used to detect Mbd gene expression in mouse tissues before and after influenza A virus (IAV) infection.
• A eukaryotic expression plasmid containing Mbd-3 was constructed and transfected into Madin-Darby canine kidney (MDCK) cells.
• Immunofluorescence, RT-PCR, and Western blot confirmed MBD-3 expression in MDCK cells.
• Mice were injected with the MBD-3 plasmid to assess its efficacy against IAV challenge.

Main Results:

• Mouse beta-defensin genes (Mbd-1, 2, and 3) were detected in trachea and lung tissues.
• IAV infection significantly increased the expression of Mbd-2 and Mbd-3.
• MDCK cells expressing MBD-3 demonstrated significant inhibition of IAV replication.
• Mice treated with MBD-3 exhibited a 71.43% survival rate against IAV challenge.

Conclusions:

• Mouse beta-defensins exhibit significant anti-influenza virus activity.
• MBD-3 expression is upregulated following IAV infection.
• Mouse beta-defensins hold promise as potential therapeutic agents for preventing and treating influenza.