Innate immunity to influenza virus: implications for future therapy

Area of Science:

• Immunology
• Virology
• Respiratory Medicine

Background:

• Innate immunity plays a crucial role in the initial defense against influenza virus infections.
• The innate immune response involves a complex interplay of soluble factors and cellular components.
• Key players include respiratory soluble inhibitors, dendritic cells, phagocytes, and natural killer cells.

Purpose of the Study:

• To review the multifaceted nature of the innate immune response to influenza.
• To discuss the activation mechanisms of innate immunity, including Toll-like receptors and RNA sensors.
• To explore the therapeutic implications of recent advances in understanding innate immunity for influenza treatment.

Main Methods:

• This is a review article, synthesizing existing research on innate immunity and influenza.
• It discusses the roles of various innate immune cells and molecular sensors.
• The review examines specific influenza strains, such as the 1918 pandemic and H5N1, in relation to innate responses.

Main Results:

• Innate immunity provides an essential early barrier against influenza through inhibitors and immune cells.
• Activation of innate responses relies on Toll-like receptors (TLR3, TLR7) and cytoplasmic RNA sensors.
• While generally protective, certain influenza strains (1918, H5N1) can elicit excessive or harmful innate immune reactions.

Conclusions:

• The innate immune system is a critical determinant of influenza infection outcome.
• Dysregulated innate responses, particularly from virulent strains, can lead to lung injury.
• Harnessing knowledge of innate immunity presents promising avenues for novel influenza therapies.