Ascomycin, also called Immunomycin, FR-900520, FK520, is an ethyl analog of tacrolimus (FK506) with strong immunosuppressant properties. It has been researched for the treatment of autoimmune diseases and skin diseases, and to prevent rejection after an organ transplant.[1]
Ascomycin acts by binding to immunophilins, especially macrophilin-12. It appears that Ascomycin inhibits the production of Th1 (interferon- and IL-2) and Th2 (IL-4 and IL-10) cytokines. Additionally, ascomycin preferentially inhibits the activation of mast cells, an important cellular component of the atopic response. Ascomycin produces a more selective immunomodulatory effect in that it inhibits the elicitation phase of allergic contact dermatitis but does not impair the primary immune response when administered systemically.[2]
Ascomycin is also the name of a fictional "antiagathic" (anti-aging) drug in James Blish's future history Cities in Flight.[4] and in its component novel They Shall Have Stars.
^Paul C, Graeber M, Stuetz A (January 2000). "Ascomycins: promising agents for the treatment of inflammatory skin diseases". Expert Opinion on Investigational Drugs. 9 (1): 69–77. doi:10.1517/13543784.9.1.69. PMID11060661. S2CID19730971.
^Yu Z, Lv H, Wu Y, Wei T, Yang S, Ju D, Chen S (December 2019). "Enhancement of FK520 production in Streptomyces hygroscopicus by combining traditional mutagenesis with metabolic engineering". Applied Microbiology and Biotechnology. 103 (23–24): 9593–9606. doi:10.1007/s00253-019-10192-8. PMID31713669. S2CID207955563.
Mollison KW, Fey TA, Krause RA, Thomas VA, Mehta AP, Luly JR (June 1993). "Comparison of FK-506, rapamycin, ascomycin, and cyclosporine in mouse models of host-versus-graft disease and heterotopic heart transplantation". Annals of the New York Academy of Sciences. 685: 55–57. doi:10.1111/j.1749-6632.1993.tb35851.x. PMID7689812. S2CID28990806.
Paul C, Graeber M, Stuetz A (January 2000). "Ascomycins: promising agents for the treatment of inflammatory skin diseases". Expert Opinion on Investigational Drugs. 9 (1): 69–77. doi:10.1517/13543784.9.1.69. PMID11060661. S2CID19730971.