Glycoprotein 130 (gp130) is a transmembrane protein which forms a hexamer with two molecules of Interleukin 6 (IL-6) and two molecules of the interleukin 6 receptor (IL-6R). gp130 is also called IL6ST, IL6-β or CD130 and can be detected in serum in a soluble form. The presence of two different soluble gp130 in human serum (90 and 110kDa), might be the result of proteolytic cleavage and/or alternative splicing of the transmembrane protein (Narazaki et al., 1993). In opposition to IL-6R, gp130 expression is not limited to IL-6 responsive cells (Hibi et al., 1990).
gp130 binds different cytokines (IL-6, IL-11, IL-27, CNTF, CLC, CT-1, LIF, OSM) through association with different receptors subunits (Jones et al., 2011). This association between gp130 and receptor subunits is necessary for the signal transduction. On the contrary, when soluble gp130 bind to IL-6, it inhibits the trans activation of the JAK/STAT3 pathway (Calabrese and Rose-John, 2014; Garbers et al., 2015).
sgp130 assay is a solid phase enzyme linked immunoassay which has been validated in the laboratory for measurement in human serum.
Calabrese, L.H., and Rose-John, S. (2014). IL-6 biology: implications for clinical targeting in rheumatic disease. Nat. Rev. Rheumatol. 10, 720–727.
Garbers, C., Aparicio-Siegmund, S., and Rose-John, S. (2015). The IL-6/gp130/STAT3 signaling axis: recent advances towards specific inhibition. Curr. Opin. Immunol. 34, 75–82.
Hibi, M., Murakami, M., Saito, M., Hirano, T., Taga, T., and Kishimoto, T. (1990). Molecular cloning and expression of an IL-6 signal transducer, gp130. Cell 63, 1149–1157.
Jones, S.A., Scheller, J., and Rose-John, S. (2011). Therapeutic strategies for the clinical blockade of IL-6/gp130 signaling. J. Clin. Invest. 121, 3375–3383.
Narazaki, M., Yasukawa, K., Saito, T., Ohsugi, Y., Fukui, H., Koishihara, Y., Yancopoulos, G.D., Taga, T., and Kishimoto, T. (1993). Soluble forms of the interleukin-6 signal-transducing receptor component gp130 in human serum possessing a potential to inhibit signals through membrane-anchored gp130. Blood 82, 1120–1126.