IL-17 Family

1. IL-17 Family Overview Interleukin-17 (IL-17) is a pro-inflammatory cytokine secreted by activated T- cells. Recently discovered related molecules are forming a family of cytokines, the IL-17 family. The prototype member of the family has been designated IL- 17A. Recent advances in the human genome sequencing and proteomics five additional members have been identified and cloned: IL-17B, IL-17C, IL-17D, IL-17E and IL-17F. The cognate receptors for the IL-17 family identified thus far are: IL-17R, IL-17RH1, IL-17RL (receptor like), IL-17RD and IL-17RE. However, the ligand specificities of many of these receptors have not been established. The IL-17 signaling system is operative in disparate tissues such as articular cartilage, bone, meniscus, brain, hematopoietic tissue, kidney, lung, skin and intestine. Thus, the evolving IL-17 family of ligands and receptors may play an important role in the homeostasis of tissues in health and disease beyond the immune system. Figure 1. Diversity of cytokine-receptor interactions.

2. Members of IL-17 family Table 1. IL-17 family related products IL17 IL17A IL17B IL-17 Family Ligands IL17C IL17D IL17E / IL25 IL17F IL17RA IL17RB IL17RC IL-17 Family Receptors IL17RD IL17RE IL-17A and IL-17F Interleukin-17 (IL-17A) is a cytokine secreted exclusively by activated T-cells. IL-17 cDNA has been isolated and cloned from the murine hybridomas (cytotoxic T lymphocyte antigen 8 (CTLA-8)) and has homology to open reading frame 13 from the T lymphotropic Herpesvirus saimiri. The human IL- 17A gene product is a protein of 150 amino acids with a molecular weight of 15 kDa, and is secreted as a disulfide linked homodimer of 30–35 kDa glycoprotein. This cytokine regulates the activities of NF-kappaB and mitogen- activated protein kinases. This cytokine can stimulate the expression of IL6 and cyclooxygenase-2 (PTGS2/COX-2), as well as enhancing the production of nitric oxide (NO).  https://www.creative-diagnostics.com/il-17-family.htm