Tofacitinib 是口服小分子 Janus 激酶抑制剂，用于治疗中度至重度类风湿性关节炎。

Tofacitinib is an oral, small molecule inhibitor of Janus kinases that is used to treat moderate-to-severe rheumatoid arthritis.

每天1.5-15 mg/kg CP-690550长期作用于小鼠,通过流式细胞仪检测,发现淋巴细胞亚群发生剂量和时间依赖性的改变.处理21天,观察到最明显的变化是脾NK1.1+TCRb细胞数降低96%.在用CP-690550（1.87-30 mg/kg,s.c.）处理后,致敏小鼠中的迟发型超敏反应（DTH）反应以剂量依赖性方式降低.CP-690550作用于异位心脏移植(DBA2供体心脏移到C57/BL6宿主)的小鼠模型,导致移植心脏的存活剂量依赖性增加,EC50(50%小鼠将保持移植 >28天时血液中药物浓度)为~60 ng/mL.CP-690550防止非人灵长类动物（NHPs,macaca fascicularis）中同种异体肾脏的排斥(50 到100 ng/ml剂量实验组和200到400 ng/ml剂量实验组的MST分别为62和83天).

CP-690550抑制IL-2诱导的增殖,比对GM-CSF诱导的增殖的效果强30倍。CP-690550高效抑制小鼠混合淋巴反应（MLR）,IC50=91 nM。在小鼠B细胞上CP-690550有效抑制IL-4诱导的CD23上调（IC50 = 57 nM）和II类主要组织相容性复合物（MHCII）表达（IC50 = 71 nM）。CP-690550是特定的口服JAK3抑制剂,作用于JAK2 和 JAK1,效果分别低20和100倍。研究显示低剂量的CP-690550通过加强Th17分化,加速实验性自身免疫脑脊髓炎的发生。

JAK3 Kinase Assay: A fragment encoding the catalytic domain of human JAK3 (785aa to 1125aa, JH1 catalytic domain) is amplified by PCR from the full length cDNA and cloned into the EcoRI site of the baculovirus transfer vector pVL1393. Recombinant baculovirus is used to infect Sf9 (Spodoptera frugipedra) cells and recombinant GSTJAK3 fusion protein is isolated on glutathione sepharose. The fusion protein is eluted with reduced glutathione and stored in buffer containing 50 mM Tris, pH 7.5, 10 mM DTT and 10% glycerol. JAK3 kinase activity is measured by ELISA as follows: Plates are coated overnight with a random L-glutamic acid and tyrosine co-polymer (4:1) (100 ug/mL). The plates are washed and recombinant JAK3 JH1:GST (100 ng/well) with or without inhibitors is incubated at room temperature for 30 minutes, after which HRP-conjugated PY20 anti-phosphotyrosine antibody (ICN) is added and developed by TMB (3,3',5,5'-tetramethylbenzidine). Other kinases (Table 1) are produced in E. coli or in insect cells, depending upon what is found to be optimal for the given kinase. The catalytic activity of tyrosine kinases is easured using the aftorementioned ELISA, whereas serine/threonine kinases are assayed using radioactive enzyme assays.

To measure IL-2-dependent proliferation, isolated lymphocytes are resuspended to a cell density of 1-2 × 106/mL in complete RPMI medium (RPMI 1640 containing 10% (w/v) fetal calf serum (FCS), 1%(w/v) penicillin and treptomycin).Phytohemagluttinin (PHA) is added to a final concentration of 10 mg/mL, and the culture incubated for 3 days at 37 °C in a humidified 5% (v/v) CO2 incubator to upregulate IL-2R and JAK3 expression. IL-2 (200U/mL), with or without CP-690,550 is then added and the cells are incubated for 72 hours at 37 °C in a humidified 5% (v/v) CO2 incubator, after which 50 mL of 3H-thymidine (5mCi/mL) is added. The plates are incubated for an additional 18 hours, harvested with a 96-well harvester, and counted on a scintillation counter. HUO3 cells are maintained in culture with granulocyte-macrophage colony stimulating factor and human foreskin fibroblasts are maintained in culture with 10% fetal calf serum. CP-690550 is added to freshly plated cells and cultured for 4 days. 3Hthymidine is added during the last 18 hours of the culture period. (Only for Reference)

477600-75-2

C16H20N6O

312.37

托法替尼;Tasocitinib;CP-690550

Ethanol:<1 mgml
H2O:<1 mgml
DMSO:58 mg/mL (185.7 mM)
Powder: -20°C for 3 years
In solvent: -80°C for 2 years