Tanaka Sachi, Furuya Kanon, Yamamoto Kana, Yamada Kazuki, Ichikawa Mikihiro, Suda Manato, Makabe Hidefumi
Department of Bioscience and Biotechnology, Graduate School of Agriculture, Shinshu University, 8304 Minami-minowa Kami-ina, Nagano 399-4598, Japan; Frontier Agriscience and Technology Center, Graduate School of Agriculture, Shinshu University, 8304 Minami-minowa Kami-ina, Nagano 399-4598, Japan.
Department of Bioscience and Biotechnology, Graduate School of Agriculture, Shinshu University, 8304 Minami-minowa Kami-ina, Nagano 399-4598, Japan.
Int Immunopharmacol. 2017 Mar;44:87-96. doi: 10.1016/j.intimp.2017.01.007. Epub 2017 Jan 13.
Procyanidins are widely found in plants and have anti-inflammatory activities. Procyanidin B2 (PCB2) inhibits production of proinflammatory cytokines in macrophages. However, there has been no study that has attempted to determine the effects of PCB2 gallates on T cell functions. In the present study, murine splenocytes were isolated and treated with PCB2 or PCB2 gallates in the presence of an anti-CD3 monoclonal antibody (mAb). PCB2 gallates, but not PCB2, inhibited proliferation and T cell activation of splenocytes after stimulation with the anti-CD3 mAb. In addition, PCB2 gallates, particularly 3,3″-di-O-gallate (3,3″-di-OG), significantly inhibited production of interferon (IFN)-γ, interleukin (IL)-12p40, and IL-17 in splenocytes, but did not suppress IL-10 production. Intracellular staining revealed that the expression of IFN-γ and IL-17 in both CD4 and CD8 T cells was obviously decreased by PCB2 3,3″-di-OG compared with PCB2, PCB2 3-OG, and PCB2 3″-OG. Treatment of isolated CD4 and CD8 T cells with procyanidins in the presence of the anti-CD3 mAb led to significant inhibition of IFN-γ production by PCB2 3,3″-di-OG in both cell types. Furthermore, PCB2 3,3″-di-OG suppressed the expression of transcription factors T-bet and RORγt that regulate IFN-γ and IL-17, respectively. In conclusion, we revealed a new mechanism through which PCB2 gallates inhibit IFN-γ and IL-17 production in T cells by down-regulation of T-bet and RORγt expression. Our results suggest that PCB2 gallates have a potential role in Th1/Th17-mediated diseases such as inflammatory and autoimmune diseases.
原花青素广泛存在于植物中，具有抗炎活性。原花青素B2（PCB2）可抑制巨噬细胞中促炎细胞因子的产生。然而，尚未有研究试图确定原花青素B2没食子酸酯对T细胞功能的影响。在本研究中，分离小鼠脾细胞，并在抗CD3单克隆抗体（mAb）存在的情况下用PCB2或原花青素B2没食子酸酯处理。原花青素B2没食子酸酯而非PCB2，可抑制抗CD3 mAb刺激后脾细胞的增殖和T细胞活化。此外，原花青素B2没食子酸酯，尤其是3,3″-二-O-没食子酸酯（3,3″-二-OG），可显著抑制脾细胞中干扰素（IFN）-γ、白细胞介素（IL）-12p40和IL-17的产生，但不抑制IL-10的产生。细胞内染色显示，与PCB2、PCB2 3-OG和PCB2 3″-OG相比，PCB2 3,3″-二-OG可显著降低CD4和CD8 T细胞中IFN-γ和IL-17的表达。在抗CD3 mAb存在的情况下，用原花青素处理分离的CD4和CD8 T细胞，导致两种细胞类型中PCB2 3,3″-二-OG对IFN-γ产生的显著抑制。此外，PCB2 3,3″-二-OG抑制分别调节IFN-γ和IL-17的转录因子T-bet和RORγt的表达。总之，我们揭示了一种新机制，即原花青素B2没食子酸酯通过下调T-bet和RORγt表达来抑制T细胞中IFN-γ和IL-17的产生。我们的结果表明，原花青素B2没食子酸酯在Th1/Th17介导的疾病如炎症和自身免疫性疾病中具有潜在作用。
