Mechanism of Action
Sirolimus stimulates cytokines like IL-2 (interleukin-2), IL-4, IL-15 and inhibits proliferation and activation of T-lymphocytes. It binds to FK binding protein 12 (FKBP12), immunophilin to generate an immunosuppressive complex. It has no effect on calcineurin activity and it inhibits the activation of a key regulatory kinase - mTOR (mammalian target of rapamycin) [20].