A major contributor to this article appears to have a close connection with its subject.(June 2020) |
Hyper-IL-6 is a designer cytokine, which was generated by the German biochemist Stefan Rose-John. [1] Hyper-IL-6 is a fusion protein of the four-helical cytokine Interleukin-6 and the soluble Interleukin-6 receptor which are covalently linked by a flexible peptide linker. [1] Interleukin-6 on target cells binds to a membrane bound Interleukin-6 receptor. [2] The complex of Interleukin-6 and the Interleukin-6 receptor associate with a second receptor protein called gp130, which dimerises and initiates intracellular signal transduction. [3] Gp130 is expressed on all cells of the human body whereas the Interleukin-6 receptor is only found on few cells such as hepatocytes and some leukocytes. [4] Neither Interleukin-6 nor the Interleukin-6 receptor have a measurable affinity for gp130. [5] Therefore, cells, which only express gp130 but no Interleukin-6 receptor are not responsive to Interleukin-6. [5] It was found, however, that the membrane-bound Interleukin-6 receptor can be cleaved from the cell membrane generating a soluble Interleukin-6 receptor. [6] The soluble Interleukin-6 receptor can bind the ligand Interleukin-6 with similar affinity as the membrane-bound Interleukin-6 receptor and the complex of Interleukin-6 and the soluble Interleukin-6 receptor can bind to gp130 on cells, which only express gp130 but no Interleukin-6 receptor. [7] The mode of signaling via the soluble Interleukin-6 receptor has been named Interleukin-6 trans-signaling whereas Interleukin-6 signaling via the membrane-bound Interleukin-6 receptor is referred to as Interleukin-6 classic signaling. [8] Therefore, the generation of the soluble Interleukin-6 receptor enables cells to respond to Interleukin-6, which in the absence of soluble Interleukin-6 receptor would be completely unresponsive to the cytokine. [8]
In order to generate a molecular tool to discriminate between Interleukin-6 classic signaling and Interleukin-6 trans-signaling, a cDNA coding for human Interleukin-6 and a cDNA coding for the human soluble Interleukin-6 receptor were connected by a cDNA coding for a 13 amino acids long linker, which was long enough to bridge the 40 Å distance between the COOH terminus of the soluble Interleukin-6 receptor and the NH2 terminus of human Interleukin-6. [9] The generated cDNA was expressed in yeast cells and in mammalian cells and it was shown that. [10]
Hyper-IL-6 has been used to test which cells depend on Interleukin-6 trans-signaling in their response to the cytokine Interleukin-6. To this end, cells were treated with Interleukin-6 and alternatively with Hyper-IL-6. Cells, which respond to Interleukin-6 alone do express an Interleukin-6 receptor whereas cells, which only respond to Hyper-IL-6 but not to Interleukin-6 alone depend in their response to the cytokine on Interleukin-6 trans-signaling. [11] It turned out that hematopoietic stem cells, [12] neural cells, [13] smooth muscle cells [14] and endothelial cells [15] are typical target cells of Interleukin-6 trans-signaling.
The Hyper-IL-6 protein has also been used to explore the physiologic role of Interleukin-6 trans-signaling in vivo. It turned out that this signaling mode was involved in many types of inflammation [16] and cancer. [17]
Hyper-IL-6 has helped to establish the concept of Interleukin-6 trans-signaling. [18] Interleukin-6 trans-signaling mediates the pro-inflammatory activities of Interleukin-6 whereas Interleukin-6 classic signaling governs the protective and regenerative Interleukin-6 activities. [19] Recently, in breast cancer patients, it was shown with the help of Hyper-IL-6 that IL-6 trans-signaling via phosphoinositid-3-kinase signaling activates disseminated cancer cells long before metastases are formed. [20] In addition, it was demonstrated in mice that Hyper-IL-6 transneuronal delivery enabled functional recovery after severe spinal cord injury. [21]
Interleukins (ILs) are a group of cytokines that are expressed and secreted by white blood cells (leukocytes) as well as some other body cells. The human genome encodes more than 50 interleukins and related proteins.
Interleukin 6 (IL-6) is an interleukin that acts as both a pro-inflammatory cytokine and an anti-inflammatory myokine. In humans, it is encoded by the IL6 gene.
Oncostatin M, also known as OSM, is a protein that in humans is encoded by the OSM gene.
Interleukin 11 is a protein that in humans is encoded by the IL11 gene.
Interleukin-15 (IL-15) is a protein that in humans is encoded by the IL15 gene. IL-15 is an inflammatory cytokine with structural similarity to Interleukin-2 (IL-2). Like IL-2, IL-15 binds to and signals through a complex composed of IL-2/IL-15 receptor beta chain (CD122) and the common gamma chain. IL-15 is secreted by mononuclear phagocytes following infection by virus(es). This cytokine induces the proliferation of natural killer cells, i.e. cells of the innate immune system whose principal role is to kill virally infected cells.
Interleukin-31 (IL-31) is a protein that in humans is encoded by the IL31 gene that resides on chromosome 12. IL-31 is an inflammatory cytokine that helps trigger cell-mediated immunity against pathogens. It has also been identified as a major player in a number of chronic inflammatory diseases, including atopic dermatitis.
Interleukin 30 (IL-30) forms one chain of the heterodimeric cytokine called interleukin 27 (IL-27), thus it is also called IL27-p28. IL-27 is composed of α chain p28 and β chain Epstain-Barr induce gene-3 (EBI3). The p28 subunit, or IL-30, has an important role as a part of IL-27, but it can be secreted as a separate monomer and has its own functions in the absence of EBI3. The discovery of IL-30 as individual cytokine is relatively new and thus its role in the modulation of the immune response is not fully understood.
Interleukin-26 (IL-26) is a protein that in humans is encoded by the IL26 gene.
Interleukin-22 (IL-22) is protein that in humans is encoded by the IL22 gene.
Type I cytokine receptors are transmembrane receptors expressed on the surface of cells that recognize and respond to cytokines with four α-helical strands. These receptors are also known under the name hemopoietin receptors, and share a common amino acid motif (WSXWS) in the extracellular portion adjacent to the cell membrane. Members of the type I cytokine receptor family comprise different chains, some of which are involved in ligand/cytokine interaction and others that are involved in signal transduction.
Glycoprotein 130 is a transmembrane protein which is the founding member of the class of tall cytokine receptors. It forms one subunit of the type I cytokine receptor within the IL-6 receptor family. It is often referred to as the common gp130 subunit, and is important for signal transduction following cytokine engagement. As with other type I cytokine receptors, gp130 possesses a WSXWS amino acid motif that ensures correct protein folding and ligand binding. It interacts with Janus kinases to elicit an intracellular signal following receptor interaction with its ligand. Structurally, gp130 is composed of five fibronectin type-III domains and one immunoglobulin-like C2-type (immunoglobulin-like) domain in its extracellular portion.
Oncostatin-M specific receptor subunit beta also known as the Oncostatin M receptor (OSMR), is one of the receptor proteins for oncostatin M, that in humans is encoded by the OSMR gene.
Interleukin 6 receptor (IL6R) also known as CD126 is a type I cytokine receptor.
Interleukin 1 receptor, type II (IL-1R2) also known as CD121b is an interleukin receptor. IL1R2 also denotes its human gene.
Interleukin 17 receptor A, also known as IL17RA and CDw217, is a human gene.
Interleukin-28 receptor is a type II cytokine receptor found largely in epithelial cells. It binds type 3 interferons, interleukin-28 A, Interleukin-28B, interleukin 29 and interferon lambda 4. It consists of an α chain and shares a common β subunit with the interleukin-10 receptor. Binding to the interleukin-28 receptor, which is restricted to select cell types, is important for fighting infection. Binding of the type 3 interferons to the receptor results in activation of the JAK/STAT signaling pathway.
The Interleukin-2 receptor alpha chain is a protein involved in the assembly of the high-affinity Interleukin-2 receptor, consisting of alpha (IL2RA), beta (IL2RB) and the common gamma chain (IL2RG). As the name indicates, this receptor interacts with Interleukin-2, a pleiotropic cytokine which plays an important role in immune homeostasis.
Interleukin 1 receptor-like 1, also known as IL1RL1 and ST2, is a protein that in humans is encoded by the IL1RL1 gene.
Interleukin 17 receptor D is a protein that in humans is encoded by the IL17RD gene.
Olamkicept, also known as soluble gp130Fc or sgp130Fc is an immunosuppressive drug candidate, which selectively blocks activities of the cytokine Interleukin-6, which are mediated by the soluble Interleukin-6. Interleukin-6 is a cytokine, which plays a dominant role in the regulation of the immune response and also in autoimmunity. Furthermore, Interleukin-6 has been demonstrated to be involved in the regulation of metabolism and body weight. Interleukin-6 also has many activities on neural cells. The biochemical principle was invented by the German biochemist Stefan Rose-John and it was further developed into a biotech compound by the Conaris Research Institute AG, which gave an exclusive world-wide license to the Swiss-based biopharmaceutical company Ferring Pharmaceuticals. In December 2016, Ferring and the biotech company I-MAB signed a licensing agreement granting I-MAB exclusive rights in Asia to Olamkicept for the treatment of autoimmune disease.