Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Shitsukawa, Tōon, Ehime 791-0295, Japan.
J Immunol. 2012 Mar 1;188(5):2164-72. doi: 10.4049/jimmunol.1100559. Epub 2012 Jan 30.
Inflammatory bowel disease (IBD), which is characterized by a dysregulated intestinal immune response, is postulated to be controlled by intestinal self-antigens and bacterial Ags. Fecal extracts called cecal bacterial Ag (CBA) have been implicated in the pathogenesis of IBD. In this study, we identified a major protein of CBA related to the pathogenesis of IBD and established a therapeutic approach using Ag-pulsed regulatory dendritic cells (Reg-DCs). Using two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry, carbonic anhydrase I (CA I) was identified as a major protein of CBA. Next, we induced colitis by transfer of CD4(+)CD25(-) T cells obtained from BALB/c mice into SCID mice. Mice were treated with CBA- or CA I-pulsed Reg-DCs (Reg-DCs(CBA) or Reg-DCs(CA1)), which expressed CD200 receptor 3 and produced high levels of IL-10. Treatment with Reg-DCs(CBA) and Reg-DCs(CA1) ameliorated colitis. This effect was shown to be Ag-specific based on no clinical response of irrelevant Ag (keyhole limpet hemocyanin)-pulsed Reg-DCs. Foxp3 mRNA expression was higher but RORγt mRNA expression was lower in the mesenteric lymph nodes (MLNs) of the Reg-DCs(CA1)-treated mice compared with those in the MLNs of control mice. In the MLNs, Reg-DCs(CA1)-treated mice had higher mRNA expression of IL-10 and TGF-β1 and lower IL-17 mRNA expression and protein production compared with those of control mice. In addition, Reg-DCs(CBA)-treated mice had higher Foxp3(+)CD4(+)CD25(+) and IL-10-producing regulatory T cell frequencies in MLNs. In conclusion, Reg-DCs(CA1) protected progression of colitis induced by CD4(+)CD25(-) T cell transfer in an Ag-specific manner by inducing the differentiation of regulatory T cells.
炎症性肠病（IBD）的特征是肠道免疫反应失调，据推测受肠道自身抗原和细菌抗原（Ags）控制。粪便提取物称为盲肠细菌 Ag（CBA）与 IBD 的发病机制有关。在这项研究中，我们鉴定了与 IBD 发病机制相关的 CBA 的主要蛋白，并建立了使用 Ag 脉冲调节树突状细胞（Reg-DC）的治疗方法。使用二维凝胶电泳和 MALDI-TOF 质谱，鉴定碳酸酐酶 I（CA I）为 CBA 的主要蛋白。接下来，我们通过将来自 BALB/c 小鼠的 CD4+CD25-T 细胞转移到 SCID 小鼠中来诱导结肠炎。用 CBA 或 CA I 脉冲调节树突状细胞（Reg-DC（CBA）或 Reg-DC（CA1））治疗小鼠，这些细胞表达 CD200 受体 3 并产生高水平的 IL-10。Reg-DC（CBA）和 Reg-DC（CA1）的治疗改善了结肠炎。这种作用是基于无关 Ag（贻贝血蓝蛋白）脉冲调节树突状细胞无临床反应的 Ag 特异性。与对照小鼠相比，Reg-DC（CA1）处理的小鼠肠系膜淋巴结（MLN）中的 Foxp3 mRNA 表达更高，但 RORγt mRNA 表达更低。在 MLN 中，与对照小鼠相比，Reg-DC（CA1）处理的小鼠具有更高的 IL-10 和 TGF-β1 mRNA 表达和更低的 IL-17 mRNA 表达和蛋白产生。此外，Reg-DC（CBA）处理的小鼠在 MLN 中具有更高的 Foxp3+CD4+CD25+和产生 IL-10 的调节性 T 细胞频率。总之，Reg-DC（CA1）通过诱导调节性 T 细胞的分化，以 Ag 特异性方式保护由 CD4+CD25-T 细胞转移诱导的结肠炎的进展。
