IL-29 (IFN lambda)

Alias: Interleukin-29, IFNλ1

IL-29 is a protein of the helical cytokine family and is a type III interferon sharing many functions with the type I family of interferons. IL-29 does not bind the IFNα/β receptor, but rather signals through a receptor composed of the IL-28R1 and IL-10R2 subunits that is expressed on most non-hematopoietic cells. Generation of native IL-29 is achieved by monocytes and dendritic cells in response to viral infection and stimulation with toll-like receptor ligands. IL-29 plays an important role in host defenses against microbes and its gene is highly upregulated in cells infected with viruses. IL-29 has significant antiviral activity and immunoregulatory properties and appears to inhibit T helper-2 (TH2) responses regarding inhibition of IL-13 production, compared with IL-4 or IL-5. The antiviral activities of IL-29 include the upregulation of MHC Class I expression on the cell surface and the expression of PKR.