The MaxDiscovery™ Human IL-29 ELISA Test Kit is designed for quantitative determination of the concentration of human IL-29 in serum, plasma, and cell culture supernatant. Human interleukin 29 (IL-29) is a cytokine distantly related to type I interferons and the IL-10 family. IL-29, interleukin 28A (IL-28A) and interleukin 28B (IL-28B), known as IFN?1, ?2, and ?3, are three closely related cytokine genes that form a cytokine gene cluster on chromosome 19. All three cytokines have been shown to interact with a heterodimeric class II cytokine receptor that consists of interleukin 10 receptor beta (IL-10Rß) and interleukin 28 receptor alpha (IL-28Ra). IFN?s are a novel family of interferons which mediate the induction of antiviral protection in a wide variety of cells. IFN?s share with type I IFNs an intracellular signaling pathway that drives the expression of a common set of IFN stimulated genes. IFN?s induce multiple biological activities, including the upregulation of class I MHC gene product expression to levels comparable to those induced by IFNa. Consistent with a role in antiviral protection, the mRNA expression of IFN? is detectable in cells infected with various viruses. Furthermore, monocytederived dendritic cells (important producers of IFNa) express IFN?1mRNA in response to treatment with dsRNA. TLR3 and TLR4 ligands induce IFNa, IFNß, IL-28, and IL-29 gene expression in macrophages. This is dependent upon IFNa. IFN? mediates its antiviral protection through a class II cytokine receptor complex distinct from that of type I IFNs. This is comprised of two essential receptor proteins, CRF212/IFN?R1, which is unique to IFN?, and CFR24/IL10R2, which is shared with IL10, IL22, and IL26 receptors. Whereas, the two chains of the type I IFN receptor (IFNAR1 and IFNAR2) and IL10R2 are ubiquitously expressed, IFN?R1 expression is limited and celltype dependent. IFN?R1 is not expressed by monocytes, but is upregulated during GMCSF/ IL4 induced differentiation of DCs from human monocytes, yielding iDCs which are fully responsive to IFN?. The IFN?s, IL28 and IL29, have recently been reported to prime dendritic cells to induce proliferation of Foxp3 bearing regulatory T cells. IFN? matured DCs express high levels of class I and II MHC gene products, but low levels of costimulatory molecules, and are able to specifically induce IL-2dependent proliferation of CD4+CD25+FOXP3+ T cell population with contact dependent suppressive activity on T cells.