Cyclosporin A is a cyclic undecapeptide from an extract of soil fungi. It is a powerful immunosupressant with a specific action on T-lymphocytes. It can bind to the cyclophilin and then inhibits calcineurin. Thus, it is widely used in organ transplantation to prevent rejection.
CAT No: 10-101-77
CAS No:59865-13-3
Synonyms/Alias:Cyclosporine; Ciclosporin; Cyclosporin; Cyclosporin A; Cyclosporine A; Neoral; OL 27-400; Restasis; Sandimmun; Sandimmune
Chemical Name:(3S,6S,9S,12R,15S,18S,21S,24S,30S,33S)-30-ethyl-33-[(E,1R,2R)-1-hydroxy-2-methylhex-4-enyl]-1,4,7,10,12,15,19,25,28-nonamethyl-6,9,18,24-tetrakis(2-methylpropyl)-3,21-di(propan-2-yl)-1,4,7,10,13,16,19,22,25,28,31-undecazacyclotritriacontane-2,5,8,11,14,17,20,23,26,29,32-undecone
Cyclosporin A is a cyclic undecapeptide renowned for its potent immunosuppressive properties and unique mode of action as a calcineurin inhibitor. Isolated originally from the fungus Tolypocladium inflatum, it has become a cornerstone molecule in immunology, cell signaling, and molecular biology research. Its ability to modulate T-cell activation pathways has made it an indispensable tool for probing cellular immune responses, mapping intracellular signaling cascades, and elucidating the molecular mechanisms underlying immune regulation. The compound's selective inhibition of calcineurin, a calcium/calmodulin-dependent phosphatase, has also positioned it as a model system for studying protein-protein interactions and signal transduction in lymphocyte biology.
Immunology research: Cyclosporin A is widely utilized in fundamental and applied immunological studies to investigate T-cell activation, proliferation, and differentiation. By specifically inhibiting the phosphatase activity of calcineurin, it blocks the dephosphorylation and subsequent nuclear translocation of NFAT (nuclear factor of activated T-cells), thereby suppressing the transcription of interleukin-2 and other cytokines critical for immune cell function. Researchers leverage this mechanism to dissect the molecular checkpoints governing immune activation and to differentiate between calcineurin-dependent and -independent signaling pathways in various immune cell populations.
Signal transduction studies: The compound serves as a powerful tool for elucidating intracellular signaling mechanisms, particularly those involving calcium-dependent pathways. By modulating the activity of calcineurin, Cyclosporin A enables precise interrogation of downstream signaling events, facilitating the mapping of phosphorylation cascades and transcriptional responses. Its use has been instrumental in distinguishing the roles of specific phosphatases in cellular communication, enabling the discovery of novel regulatory proteins and pathways in both immune and non-immune cells.
Transplantation biology models: In experimental transplantation settings, Cyclosporin A is frequently employed to generate immunosuppressed animal models for the study of graft acceptance, rejection mechanisms, and tolerance induction. Its capacity to suppress host-versus-graft responses allows researchers to explore the cellular and molecular determinants of transplant compatibility, chronic rejection, and the long-term fate of transplanted tissues. Such models are essential for advancing the understanding of immunological barriers to transplantation and for evaluating new strategies aimed at promoting graft survival.
Protein-protein interaction assays: The unique binding properties of Cyclosporin A to cyclophilins have made it a valuable probe in protein interaction studies. Its ability to form a ternary complex with cyclophilin and calcineurin is exploited in biochemical assays to investigate protein folding, chaperone activity, and the structural basis of enzyme inhibition. These studies provide insights into the conformational dynamics of immunophilins and their role in cellular homeostasis, as well as informing the rational design of novel inhibitors targeting similar pathways.
Cellular stress and apoptosis research: Beyond its immunosuppressive effects, Cyclosporin A is employed to study mitochondrial function, oxidative stress, and apoptosis in various cell types. By modulating the mitochondrial permeability transition pore (mPTP), it enables researchers to investigate the interplay between cellular stress responses, mitochondrial integrity, and programmed cell death. This application is particularly relevant in studies of neurodegeneration, cardiomyocyte survival, and ischemia-reperfusion injury, where mitochondrial dysfunction and apoptotic signaling are central to disease progression and cellular fate decisions.
Cyclosporin A (CyA) is a powerful immunosuppressive agent whose lack of myelotoxicity makes it unique among nonsteroidal drugs currently given for immunosuppression. It has been used with initial success in recipients of kidney, liver, bone marrow and pancreas transplants, and it may also have clinical application in the treatment of autoimmune disorders. In regard to its use in transplant recipients, there are many remaining questions about its mechanism of action, the optimum dose, whether it should be used alone or with other immunosuppressants, whether it can suppress chronic rejection and what its long-term side effects may be. These questions can only be answered by further careful laboratory investigation and controlled clinical trials. Until then, CyA should only be administered in centres experienced in its use.
Laupacis, A., Keown, P. A., Ulan, R. A., McKenzie, N., & Stiller, C. R. (1982). Cyclosporin A: a powerful immunosuppressant. Canadian Medical Association Journal, 126(9), 1041.
CsA, FK-506, and rapamycin are microbial products with potent immunosuppressive properties that result primarily from a selective inhibition of T lymphocyte activation. Although chemically unrelated, CsA and FK-506 affect a similar subset of calcium-associated signaling events involved in the regulation of lymphokine gene expression, activation-driven T-cell death and exocytosis. Rapamycin has structural similarity with FK-506 but suppresses T-cell activation at a different level, mainly through inhibition of proliferation induced by growth-promoting lymphokines. CsA interacts with an abundant 17 kDa protein, termed cyclophilin, that possesses peptidyl-prolyl cis-trans isomerase (PPIase) activity. Additional, minor cyclophilin-like molecules have been identified. Both FK-506 and rapamycin interact with FKBP, a 12 kDa protein, which, although unrelated to cyclophilin, is also abundant and ubiquitous, has a similar enzymatic activity, and is a member of a larger family of FKBPs.
Sigal, N. H., & Dumont, F. J. (1992). Cyclosporin A, FK-506, and rapamycin: pharmacologic probes of lymphocyte signal transduction. Annual review of immunology, 10(1), 519-560.
The site of action of the immunosuppressive drug cyclosporin A in in vitro cytotoxic allograft responses has been localized. General cytotoxic effects of the drug on proliferating T cells became apparent at concentrations of 500-1000 ng/ml, while selective effects were observed at concentrations of 10-100 ng/ml. The selective effects included a blockade of interleukin 2 release from activated T helper cells on the one hand and inhibition of interleukin 1 release from splenic adherent cells on the other. While cyclosporin A did not interfere with the intracellular events required for the activation and subsequent clonal expansion of alloreactive T cells, the lack of interleukin 1 and interleukin 2 induced by cyclosporin A results in an inability of T responder cells to mount cytotoxic allograft responses in vitro.
Bunjes, D., Hardt, C., Röllinghoff, M., & Wagner, H. (1981). Cyclosporin A mediates immunosuppression of primary cytotoxic T cell responses by impairing the release of interleukin 1 and interleukin 2. European journal of immunology, 11(8), 657-661.
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