Tofacitinib (CP-690550,Tasocitinib)

Tofacitinib（CP-690550，Tasocitinib）是一种新型可口服的Janus激酶抑制剂，可用作靶向免疫调节剂。Tofacitinib主要抑制与JAK3、JAK1或两者均相关的异源二聚体受体信号，对JAK2配对受体具有功能选择性。Tofacitinib对JAK1和JAK3的抑制可阻断几种细胞因子的信号，包括白细胞介素2、4、7、9、15和21。这些细胞因子对于淋巴细胞的活化、功能和增殖是不可或缺的。Tofacitinib也是STAT分子的抑制剂。最近的机制研究表明，tofacitinib与多个JAKs和推测的其它激酶相互作用。

参考文献：
Roy Fleischmann, Joel Kremer, John Cush, Hendrik Schulze-Koops, Carol A.  Connell, John D. Bradley, David Gruben, Gene V. Wallenstein, Samuel H. Zwillich, and Keith S. Kanik. Placebo-Controlled Trial of Tofacitinib Monotherapy in Rheumatoid Arthritis. N Engl J Med 2012; 367:495-507
William J.  Sandborn, Subrata Ghosh, Julian Panes, Ivana Vranic, Chinyu Su, Samantha Rousell, Wojciech Niezychowski. Tofacitinib, an Oral Janus Kinase Inhibitor, in Active Ulcerative Colitis. N Engl J Med 2012; 367:616-624.
Keisuke Maeshima, Kunihiro Yamaoka, Satoshi Kubo, Kazuhisa Nakano, Shigeru Iwata, Kazuyoshi Saito, Masanobu Ohishi, Hisaaki Miyahara, Shinya Tanaka, Koji Ishii, Hironobu Yoshimatsu, Yoshiya Tanaka.  The JAK Inhibitor Tofacitinib Regulates Synovitis Through Inhibition of Interferon- and Interleukin-17 Production by Human CD4 T Cells. Arthritis & Rheumatism. 2012. 64(6): 1790–1798.