Interleukin-6 (IL-6, Interleukin 6, B-cell stimulatory factor 2, BSF-2, BSF2, IFNB2, interferon beta 2, hybridoma growth factor, HGF, HSF) is a key mediator of the acute inflammatory response. It is a glycoprotein cytokine coded for at 7p21 by the IL6 gene with both pro-inflammatory and anti-inflammatory properties. It has hormonal properties, as for example with its release from muscles on exercise.
It activates the interleukin-6 receptor and thus the interleukin-6 pathway acute phase response with the membrane bound form of the receptor or the alternative trans-signalling pathway with the soluble form of the receptor (mainly in endothelial or smooth muscle cells).Interleukin-6 pathway activation causes:
- Final differentiation of B cells into Ig-secreting cells
- Macrophage reaction to pathogen associated molecular patterns
- Nerve cell differentiation
- Hepatocyte release of acute phase reactants
- Energy mobilization
- Stimulates osteoclast formation