User:Fangmz/InterferonTypeIII

= Interferon type III =

The type III interferon group consists of four IFN-λ (lambda) molecules called IFN-λ1, IFN-λ2, IFN-λ3 (formerly IL29, IL28A and IL28B respectively), and IFN-λ4. These interferons signal through a receptor complex consisting of IL10RB (also called IL10R2 or CRF2-4) and IFNLR1 (formerly called IL28RA, CRF2-12). The interferon lambda genes lie in the 19q13.13 chromosomal region. IFNL4 is located between IFNL3 and IFNL2. Interferon lambda proteins are involved in immune response to viral infection. Signaling initiated by IFN-λ triggers the JAK-STAT pathway, leading to the expression of numerous interferon-stimulated genes with anti-viral and anti-proliferative effects.

All four interferon lambda proteins have antiviral effects in vitro, however, a genetic variant that produces the IFNL4 protein is linked to impaired clearance of hepatitis C virus. The explanation for this paradox is not fully understood.

In contrast to the ubiquitous expression of receptors for IFN-α, IFNLR1 is largely restricted to tissues of epithelial origin. Therefore, interferon lambda proteins may have evolved specifically to protect tissue barriers.