Interferon-λ: Immune Functions at Barrier Surfaces and Beyond

Area of Science:

• Immunology
• Virology
• Molecular Biology

Background:

• Type III interferons (IFN-λ), also known as interleukin-28 (IL-28) and IL-29, were discovered in 2003.
• Initially, their antiviral function was presumed to mirror type I IFNs (IFN-α and IFN-β) through interferon-stimulated genes (ISGs).
• IFN-λ preferentially induces antiviral ISGs in epithelial cells, but emerging evidence points to broader functions.

Purpose of the Study:

• To review recent advancements in understanding IFN-λ functions beyond epithelial antiviral responses.
• To explore the role of IFN-λ in restricting viral dissemination and resolving chronic infections.
• To discuss the broader implications of IFN-λ in immunity, autoimmunity, and cancer.

Main Methods:

• Review of recent scientific literature and studies.
• Analysis of viral infection models in mice lacking IFN-λ signaling.
• Examination of single nucleotide polymorphism (SNP) associations with human diseases.

Main Results:

• IFN-λ exhibits antiviral activity in diverse cell types and tissues, not limited to epithelial cells.
• IFN-λ plays a role in restricting virus spread to the brain.
• IFN-λ contributes to the clearance of chronic viral infections in the gastrointestinal tract.

Conclusions:

• IFN-λ is a critical component of the innate immune response at mucosal surfaces and beyond.
• IFN-λ influences both innate and adaptive immunity, with implications for autoimmune diseases and cancer progression.
• IFN-λ holds potential for therapeutic applications in various human diseases.