Suplatast Tosilate (IPD 1151T) is a novel capsular anti-asthmatic drug. It ( IC50 above 100 μM) inhibits both IgE production, IL-4 and IL-5 synthesis.

IL-5:100 μM, IgE:100 μM, IL-4:100 μM

Suplatast tosilate 对离体小鼠脾脏和人类外周血 B 细胞抗体的产生有抑制作用，IC50 ＞100 nM。Suplatast tosilate 可抑制小鼠和人类细胞因子 IFN-γ、IL-2、IL-4、IL-5 和 IL-10 的产生，IC50 ＞100 nM。[1] 在自体 B 细胞中，由 SN-4 介导的 Cryj1 依赖性 IgE 合成的诱导作用会被 Suplatast tosilate（1 和 10 μg/ml）以浓度依赖的方式抑制。Suplatast tosilate（1 和 10 μg/ml）能以浓度依赖的方式有效抑制 IL-4 的产生，无论是在自体 APC 存在下由 SN-4 与 Cryj1 刺激 3 天产生的 IL-4 还是由正常供体的 PHA 刺激 PBMC 产生的 IL-4 都是如此。[2] Suplatast tosilate 能明显抑制未成熟树突状细胞（DCs）上 CD1a、CD80 和 CD86 的表达，以及成熟 DCs 上 CD1a、CD80、CD83 和 CD86 的表达。Suplatast tosilate 还能显著抑制 CCL17、IL-12p70 和 IL-12p40 的分泌，但不影响 IL-10 的分泌。异体 CD4(+) T 细胞对 Suplatast tosilate 处理过的 DC 的增殖反应受到抑制。此外，经 Suplatast tosilate 处理的 DCs 刺激 CD4（+）T 细胞产生 IFN-gamma 和 IL-5 的能力受损。[4]

Suplatast tosilate（100 mg/kg/100 微升）能显著减少 BALF 中的总细胞数和嗜酸性粒细胞数（约-40%），并几乎完全抑制抗原诱导的 BHR 的发展。组织学研究结果证实，肺部粘膜下细胞浸润减少，支气管上皮细胞损伤明显受到抑制。卵清蛋白特异性 IgE 略有下降，但幅度很大。与未使用 Suplatast tosilate 的小鼠相比，使用 Suplatast tosilate 治疗的小鼠 BALF 中的 IL-4、IL-5 和 IL-13 水平明显降低。[3]

ssay for cytokines: The cultures for cytokine production are set up at 37 °C as follows: the mixtures of SN-4 and autologous APC (each 1 × 105 cells/well) are cultured for 3 days with 50 μg/mL of Cry j1 in a total volume of 0.2 mL in round-bottomed micro plates; PBMC (2 × 10 5 cells/well) from normal donors are cultured for 24 hours with 10 μg/ml of PHA in a total volume of 0.2 mL in flat-bottomed, 96-well micro plates; and purified T cells (1 × 105 cells/well) from normal donors are cultured in a total volume of 1 ml for 24 hours with anti-CD3 mAb that have been immobilized on flat-bottomed, 24-well plates at a concentration of 5 μg/ml. Cytokines in the culture supernatants are quantitatively assayed by the following commercially available kits: IL-4 and IFN-γ. The sensitivity of the assay is 30 pg/mL for IL-4 and 1 U/mL for IFN-γ.

Allogeneic responder CD4+ T cells obtained from healthy subjects are purified from PBMCs by negative depletion of CD14+, CD16+, CD19+, CD56+, and CD8+ cells using magnetic cell separation system micro-beads and columns. After 7 days of culture with GM-CSF and IL-4, iDCs differentiated from monocytes in the presence or absence of Suplatast tosilate (10 and 100 mg/ mL) are co-cultured with purified 1×10 5 allogeneic CD41 T cells at varying ratios of iDCs in 96-well round bottomed culture plates for 5 days. Cells are pulsed with 1 μCi of 3H-methylthymidine for the last 8 hours of the culture period. Incorporated radioactivity is counted with a liquid scintillation counter, and proliferative responses are expressed as the mean 3 H-methylthymidine incorporation (counts per minutes) of triplicate wells_SEM. Proliferation of DCs alone or CD4+ T cells alone is also assessed.(Only for Reference)