Wang Shushu, Xie Yuanyuan, Yang Xiaodi, Wang Xuesong, Yan Ke, Zhong Zhengrong, Wang Xiaowei, Xu Yuanhong, Zhang Yi, Liu Fang, Shen Jilong
Department of Immunology, Anhui Medical University, Hefei, 230022, China.
Department of Pathogen Biology, Provincial Laboratories of Pathogen Biology and Zoonoses Anhui, Hefei, 230022, China.
Parasit Vectors. 2016 Jan 4;9:6. doi: 10.1186/s13071-015-1288-1.
Helminth infections and their components have been shown to have a protective effect on autoimmune diseases. The isolated purified protein from Schisotosoma japonicum and its potential therapeutic effect on trinitrobenzene sulfonic acid (TNBS)-induced colitis could provide an alternative way to treat inflammatory bowel disease (IBDs).
Colitis was induced in Balb/c mice by rectal administration of 2.5% TNBS, followed by intraperitoneal injection of rSjcystatin 50 μg at 6 h and 24 h afterwards. The inflammation was monitored by recording weight change, stool character and bleeding, colon length, macroscopic score (MAO), microscopic score (MIO), myeloperoxidase activity (MPO) and disease activity index (DAI). The potential underlying mechanism was investigated by examining cytokine profiles including Th1 (IFNγ), Th2 (IL-4), Th17 (IL-17A) and Treg subsets from lymphocytes of spleen, mesenteric lymph nodes (MLN) and intestinal lamina propria mononuclear cells (LPMCs) by flow cytometry. The mRNA relative expressions of the cytokines in splenocytes and MLN were analysed by quantitative real time reverse-transcriptase polymerase chain reaction (qRT-PCR). Simultaneously, the concentrations of the cytokines in the colon homogenate supernatants were tested by enzyme-linked immunosorbent assay (ELISA) and key transcription factors were detected by Western blotting.
Administration of rSjcystatin significantly reduced inflammatory parameters and ameliorated the severity of the TNBS-induced colitis through decreasing IFNγ in three organs and lifting the level of IL-4, IL-13, IL-10, and TGF-β in the colon tissues, with uptrending Tregs in the MLN and LPMC.
The findings provide evidence that rSjcystatin has a therapeutic potential for diminishing colitis inflammation in Balb/c mice. The immunological mechanism may involve the down-regulation of Th1 response and up-regulation of Th2 and Tregs in the MLN and colon.
蠕虫感染及其成分已被证明对自身免疫性疾病具有保护作用。日本血吸虫分离纯化蛋白及其对三硝基苯磺酸（TNBS）诱导的结肠炎的潜在治疗作用可为治疗炎症性肠病（IBD）提供一种替代方法。
通过直肠给予2.5% TNBS诱导Balb/c小鼠发生结肠炎，随后在6小时和24小时后腹腔注射50μg重组日本血吸虫半胱氨酸蛋白酶抑制剂（rSjcystatin）。通过记录体重变化、粪便性状和出血情况、结肠长度、宏观评分（MAO）、微观评分（MIO）、髓过氧化物酶活性（MPO）和疾病活动指数（DAI）来监测炎症。通过流式细胞术检测脾脏、肠系膜淋巴结（MLN）和肠固有层单核细胞（LPMC）淋巴细胞中包括Th1（IFNγ）、Th2（IL-4）、Th17（IL-17A）和调节性T细胞（Treg）亚群在内的细胞因子谱，研究潜在的作用机制。通过定量实时逆转录聚合酶链反应（qRT-PCR）分析脾细胞和MLN中细胞因子的mRNA相对表达。同时，通过酶联免疫吸附测定（ELISA）检测结肠匀浆上清液中细胞因子的浓度，并通过蛋白质免疫印迹法检测关键转录因子。
给予rSjcystatin可显著降低炎症参数，并通过降低三个器官中的IFNγ以及提高结肠组织中IL-4、IL-13、IL-10和转化生长因子-β（TGF-β）的水平来改善TNBS诱导的结肠炎的严重程度，同时MLN和LPMC中的Tregs呈上升趋势。
这些发现提供了证据表明rSjcystatin对减轻Balb/c小鼠的结肠炎炎症具有治疗潜力。免疫机制可能涉及MLN和结肠中Th1反应的下调以及Th2和Tregs的上调。
