BACKGROUND AND PURPOSE A series of benzothiazole derivatives were screened for immunosuppressive activity; of these compounds BD750 was found to be the most effective immunosuppressant. The purpose of the current study was to determine the immunosuppressive activity of BD750 on T cell proliferation and its potential mode of action. EXPERIMENTAL APPROACH T cell proliferation, CD25 and CD69 expression and cell cycle distribution were measured in vitro by flow cytometry. Cell viability was determined by CCK-8 assay. Cytokine levels were measured by elisa. The activation of signal-regulated molecules was assessed by Western blot analysis. The effects of BD750 were evaluated in vivo in a mouse model of delayed-type hypersensitivity. KEY RESULTS BD750 significantly inhibited mouse and human T cell proliferation, stimulated either by anti-CD3/anti-CD28 monoclonal antibodies or by an alloantigen, in a dose-dependent manner in vitro. No obvious cytotoxic effects of BD750 were observed in our experimental conditions. Furthermore, BD750 did not inhibit CD25 and CD69 expression or IL-2 and IL-4 secretion, but induced cell cycle arrest at the G(0) /G(1) phase in activated T cells. In IL-2-stimulated CTLL-2 cells and primary activated T cells, BD750 inhibited cell proliferation and STAT5 phosphorylation, but not Akt or p70S6K phosphorylation. BD750 also reduced the T cell-mediated delayed-type hypersensitivity response in mice in a dose-dependent manner. CONCLUSION AND IMPLICATIONS These data indicate that BD750 inhibits IL-2-induced JAK3/STAT5-dependent T cell proliferation. BD750 has the potential to be used as a lead compound for the design and development of new immunosuppressants for preventing graft rejection and treating autoimmune diseases.

中文翻译：

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BD750 是一种苯并噻唑衍生物，通过影响 JAK3/STAT5 信号通路抑制 T 细胞增殖。

背景和目的 筛选了一系列苯并噻唑衍生物的免疫抑制活性；在这些化合物中，BD750 被发现是最有效的免疫抑制剂。本研究的目的是确定 BD750 对 T 细胞增殖的免疫抑制活性及其潜在的作用方式。实验方法通过流式细胞术在体外测量T细胞增殖、CD25和CD69表达以及细胞周期分布。通过CCK-8测定确定细胞活力。通过ELISA测量细胞因子水平。通过蛋白质印迹分析评估信号调节分子的活化。在迟发型超敏反应的小鼠模型中体内评估了 BD750 的作用。主要结果 BD750 显着抑制小鼠和人类 T 细胞增殖，在体外以剂量依赖性方式被抗 CD3/抗 CD28 单克隆抗体或同种抗原刺激。在我们的实验条件下没有观察到 BD750 的明显细胞毒性作用。此外，BD750 不抑制 CD25 和 CD69 表达或 IL-2 和 IL-4 分泌，但在激活的 T 细胞中诱导细胞周期停滞在 G(0)/G(1) 期。在 IL-2 刺激的 CTLL-2 细胞和原代活化 T 细胞中，BD750 抑制细胞增殖和 STAT5 磷酸化，但不抑制 Akt 或 p70S6K 磷酸化。BD750 还以剂量依赖性方式降低了小鼠中 T 细胞介导的迟发型超敏反应。结论和意义 这些数据表明 BD750 抑制 IL-2 诱导的 JAK3/STAT5 依赖性 T 细胞增殖。