Mouse IFN-lambda is a Type III interferon that signals through a receptor largely restricted to epithelial cells, giving it a more tissue-focused antiviral role than Type I interferons like IFN-alpha and IFN-beta. PBL offers recombinant mouse IFN-lambda 3 (IL-28B), with and without carrier protein.
Mouse IFN-lambda 3 (IL-28B) is a 193-amino-acid precursor protein that signals through IFNLR1 and IL10RB, a receptor pair expressed mainly on epithelial cells of the respiratory, gastrointestinal, and reproductive tracts rather than broadly across nucleated cells like the Type I IFN receptor. Receptor engagement activates JAK1 and TYK2, which phosphorylate STAT1 and STAT2 to form the ISGF3 complex with IRF9, inducing antiviral genes such as Mx proteins and OAS through ISRE elements, the same downstream pathway used by IFN-alpha and IFN-beta. Mouse IL-28B is induced by viral infection and double-stranded RNA sensed through Toll-like receptors and RIG-I-like helicases, and it shares 61-62% amino acid identity with its human counterparts (IL-28A and IL-28B); notably, its target tissue response differs by species, since mouse hepatocytes are largely unresponsive to IFN-lambda while human hepatocytes respond directly, a distinction relevant to translating results between mouse and human liver studies.