Kinase activity is recorded via a competition binding assay of selected kinases that are fused to a proprietary tag. Measurements of the amount of kinase binds to an immobilized, active-site directed ligand in the presence and absence of the test compound (e.g., Tofacitinib) provide a % of DMSO control for binding of ligand. Activities between 0 and 10 are selected for Kd determinations. Dendrogram representations are generated by an in-house visualization tool designated PhyloChem^[1].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

Human CD4⁺ positive cells are enriched from peripheral blood mononuclear cells obtained from a healthy donor by magnetic separation (CD4⁺ MACS beads). CD4⁺ cells are activated for 3 days with plate bound anti-CD3 and anti CD28 antibodies (5 ug/mL each), and then expanded for another 4 days in the presence of IL-2 (50 U/mL). Cells are rested overnight in 1% RPMI, and pre-incubated with Tofacitinib or DMSO control for 1 hour at indicated concentrations (5 nM, 50 nM, 500 nM; DMSO concentration is equal in all preparations) and then activated with IL-2 (1000 u/mL) or IL-12 (100 ng/mL) for 15 minutes. Cells (10×10⁶/condition) are lysed in 1% Triton-x lysis buffer and equal amounts of cell lysate are run in NuPage Bis-Tris gel (4-12% gradient). Proteins are transferred onto nitrocellulose membrane. Detection is done with indicated antibodies using Odyssey western blotting system^[1].

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

Mice^[2]
Female BALB/c mice (6-8 weeks old) are used. Mice receive Tofacitinib in PEG300 (100 mg/mL) or vehicle alone (PEG300) by osmotic pump infusion (Alzet Model 2004, 0.25 μL/hour, 28 days). Four days prior to immunization, mice are anesthetized and their dorsal surface is shaved. A one cm incision is made on the back to create a subcutaneous pocket and insert the pump. The incision site is closed with wound clips. Mice are injected weekly (i.p.) with SS1P recombinant immunotoxin (RIT; 5 μg/mouse) beginning on day 0; control mice received injections of saline alone. Every week before SS1P or vehicle immunization, 50 μL of blood is drawn to obtain serum samples. Sera are stored at −80°C until analyzed.
Rats^[3]
Adjuvant-induced arthritis (AIA) is induced in female Lewis rats. Rats are randomized according to hind paw volume and assigned to Tofacitinib or vehicle treatment regimens. Groups of 7-8 rats per treatment group, and normal naive rats (n=4 per group), are euthanized either 4 hours, 4 days, or 7 days after beginning treatment (days 16, 20, and 23 after immunization, respectively). Tofacitinib is suspended in 0.5% methylcellulose/0.025% Tween 20 for in vivo studies. Once-daily oral administration of vehicle or Tofacitinib (6.2 mg/kg) is initiated on day 16 following immunization and continued through day 23. Paw volumes are reassessed 4 and 7 days after the beginning of treatment (days 20 and 23 after immunization, respectively). For micro-computed tomography (micro-CT) imaging, as well as tartrate-resistant acid phosphatase (TRAP) staining in paw tissue, AIA is induced in a separate cohort of Lewis rats.

MCE has not independently confirmed the accuracy of these methods. They are for reference only.

• [1]. Jiang JK, et al. Examining the chirality, conformation and selective kinase inhibition of 3-((3R,4R)-4-methyl-3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)piperidin-1-yl)-3-oxopropanenitrile (CP-690,550). J Med Chem. 2008 Dec 25;51(24):8012-8.  [Content Brief]

  [2]. Onda M, et al. Tofacitinib suppresses antibody responses to protein therapeutics in murine hosts. J Immunol. 2014 Jul 1;193(1):48-55.  [Content Brief]

  [3]. LaBranche TP, et al. JAK inhibition with tofacitinib suppresses arthritic joint structural damage through decreased RANKL production. Arthritis Rheum. 2012 Nov;64(11):3531-42.  [Content Brief]

  [4]. Calama E, et al. Tofacitinib ameliorates inflammation in a rat model of airway neutrophilia induced by inhaled LPS. Pulm Pharmacol Ther. 2017 Apr;43:60-67.  [Content Brief]