Interleukin 6 (IL-6) is a prototypic member of the IL-6 superfamily of cytokines. It is a pleiotropic cytokine that plays important roles in immune response, inflammation, hematopoiesis, bone metabolism, nerve cell functions, and cancer progression.

IL-6 is secreted by a variety of lymphoid and non-lymphoid cells including T cells, B cells, monocytes, fibroblasts, hepatocytes, endothelial cells, keratinocytes, etc. Mature rat IL-6 is a 187 aa residue protein. At the protein sequence level, there is approximately 39% identity between rat and human, and 87% identity between mouse and rat IL-6. The production of IL-6 can be induced by numerous signals such as mitogenic or antigenic stimulation, lipopolysaccharides, calcium ionophores, cytokines, and viruses.

IL-6 induces signaling through a cell surface heterodimeric receptor complex composed of a ligand binding subunit (IL-6 R) and a subunit (gp130) that acts as the universal signal-transducing element for all IL-6 family cytokines. Binding of IL-6 to IL-6 R recruits gp130 to form a trimeric complex that dimerizes to form a hexameric complex, which transduces IL-6 signal. Binding of IL-6 to soluble IL-6R can also induce trans-signaling, which elicit response from gp130-expressing cells that lack of cell surface IL-6R. Trans-signaling enables a wider range of cell types to respond to IL-6, as the expression of gp130 is ubiquitous.

IL-6 activity is essential for the transition from acute inflammation to either acquired immunity or chronic inflammatory disease. IL-6 is a key factor that reciprocally regulates Th17 and FOXP3(+) Treg differentiation by inhibition of TGF-β induced FOXP3 and induction of RORγ, a Th17 lineage-specific transcription factor.

Elevated serum IL-6 levels have been observed in a number of pathological conditions, including bacterial and viral infections, trauma, autoimmune diseases, inflammations, and malignancies.

BioLegend's LEGEND MAX™ Rat IL-6 ELISA Kit is a sandwich Enzyme-Linked Immunosorbent Assay (ELISA), in which a rat IL-6-specific polyclonal antibody is pre-coated on a 96-well strip-well plate.

BioLegend's LEGEND MAX™ Rat IL-6 ELISA Kit is specifically designed for the accurate quantitation of rat IL-6 from cell culture supernatant, serum, plasma, or other bodily fluids. It is ready-to-use, accurate, and sensitive.