IFITM3 reduces infectious bursal disease virus proliferation by regulating interferon expression

Area of Science:

• Virology
• Immunology
• Cell Biology

Background:

• Interferon-inducible transmembrane protein 3 (IFITM3) is known for its antiviral properties.
• Infectious bursal disease virus (IBDV) severely impacts chicken immunity, leading to secondary infections and mortality.
• Previous research indicated IBDV infection upregulates chicken IFITM3 expression, but its specific role was unclear.

Purpose of the Study:

• To elucidate the function of chicken IFITM3 in IBDV infection.
• To investigate the antiviral mechanisms of IFITM3 against IBDV.
• To explore the relationship between IFITM3, interferon (IFN) production, and the IKB gene.

Main Methods:

• Overexpression vectors for IFITM3 were created and transfected into chicken cell lines (HD-11 and DF-1).
• IFITM3 was inhibited using small interfering RNA (siRNA).
• The expression levels of IFITM3, IBDV, and various interferons (IFN-α, IFN-β, IFN-γ) were analyzed. The role of the IKB gene in IFITM3-mediated IFN regulation was assessed.

Main Results:

• Overexpression of IFITM3 significantly suppressed IBDV proliferation in chicken cells.
• Inhibition of IFITM3 using siRNA led to increased IBDV proliferation.
• IFITM3 overexpression promoted the expression of IFN-α, IFN-β, and IFN-γ.
• The IKB gene was identified as a key factor influencing IFITM3's regulatory effect on IFN production.

Conclusions:

• Chicken IFITM3 exhibits antiviral activity against IBDV, likely by modulating interferon responses.
• IFITM3 may enhance its antiviral effect through a positive feedback mechanism on interferon production.
• The IKB gene plays a crucial role in the pathway through which IFITM3 regulates interferon-mediated antiviral activity.