Bruckner Ramona S, Spalinger Marianne R, Barnhoorn Marieke C, Feakins Roger, Fuerst Alois, Jehle Ekkehard C, Rickenbacher Andreas, Turina Matthias, Niechcial Anna, Lang Silvia, Hawinkels Lukas J A C, van der Meulen-de Jong Andrea E, Verspaget Hein W, Rogler Gerhard, Scharl Michael
Department of Gastroenterology and Hepatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, The Netherlands.
Inflamm Bowel Dis. 2021 Mar 15;27(4):538-549. doi: 10.1093/ibd/izaa240.
Fistulas represent a frequent and severe complication in patients with Crohn disease (CD). Tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta, and interleukin (IL)-13 are known to trigger epithelial-mesenchymal transition (EMT), promoting fistula formation. Here, we investigated the role of T-lymphocytes (T cells) in fistula pathogenesis.
CD3+CD8-, CD3+CD8+, or CD45+CD3- cells from healthy volunteers, patients with CD, and patients with CD with perianal fistula were co-cultured with HT-29 cells. The EMT, cytokine production, and mRNA expression were analyzed. Perianal CD fistula specimens were immunohistochemically stained for cytokines and their receptors. The effect of cytokines on EMT induction was investigated using an EMT spheroid model.
Patients with CD with fistula revealed more CD3+CD8- and less CD3+CD8+ T cells in blood than healthy control patients and patients with CD without fistula. In perianal fistula specimens, CD4+ cells-and to a lesser extent CD8+ cells-were highly present around fistula tracts. When co-cultured with HT-29 cells, both cell subsets promoted EMT-related gene expression and TNF-α production in a time-dependent manner. The CD3+CD8- T cells from patients with CD with fistula also produced higher amounts of IL-13 than cells from healthy control patients or patients with CD without a fistula. We found that IL-22 and IL-22Rα1 were highly expressed in perianal CD fistula specimens and that IL-22 cotreatment potentiated TNF-α-induced EMT in HT-29 spheroids.
Our data indicate that both CD3+CD8- and CD3+CD8+ T cells play an important role in the pathogenesis of perianal CD fistulas by the secretion of TNF-α. Our data support clinical evidence indicating that anti-TNF-α therapy is effective in fistula treatment and identify IL-13 and IL-22 as possible novel therapeutic targets for fistula therapy.
肛瘘是克罗恩病（CD）患者常见且严重的并发症。已知肿瘤坏死因子-α（TNF-α）、转化生长因子-β和白细胞介素（IL）-13可引发上皮-间质转化（EMT），促进肛瘘形成。在此，我们研究了T淋巴细胞（T细胞）在肛瘘发病机制中的作用。
将来自健康志愿者、CD患者以及患有肛周肛瘘的CD患者的CD3⁺CD8⁻、CD3⁺CD8⁺或CD45⁺CD3⁻细胞与HT-29细胞共培养。分析EMT、细胞因子产生及mRNA表达情况。对肛周CD肛瘘标本进行细胞因子及其受体的免疫组化染色。使用EMT球体模型研究细胞因子对EMT诱导的影响。
与健康对照患者和无肛瘘的CD患者相比，患有肛瘘的CD患者血液中CD3⁺CD8⁻ T细胞更多，CD3⁺CD8⁺ T细胞更少。在肛周肛瘘标本中，瘘管周围大量存在CD4⁺细胞，CD8⁺细胞数量相对较少。与HT-29细胞共培养时，这两种细胞亚群均以时间依赖性方式促进EMT相关基因表达和TNF-α产生。患有肛瘘的CD患者的CD3⁺CD8⁻ T细胞产生的IL-13也比健康对照患者或无肛瘘的CD患者的细胞更多。我们发现IL-22和IL-22Rα1在肛周CD肛瘘标本中高表达，并发现IL-22共处理可增强TNF-α诱导HT-29球体发生的EMT。
我们的数据表明，CD3⁺CD8⁻和CD3⁺CD8⁺ T细胞通过分泌TNF-α在肛周CD肛瘘发病机制中起重要作用。我们的数据支持抗TNF-α治疗对肛瘘治疗有效的临床证据，并确定IL-13和IL-22为肛瘘治疗可能的新靶点。
