There has been no report investigating the role of IL-38 in inflammatory bowel diseases (IBD). Therefore, we investigated the expression of IL-38 in IBD patients and its role in regulating intestinal inflammation. The levels of IL-38 were significantly elevated in the intestine of IBD patients and DSS-induced colitis mice. Immunofluorescence analysis revealed that B cell, not macrophage or T cell, was the source of IL-38 in the intestine. We found that rIL-38 treatment significantly attenuated DSS-induced colitis, including alleviation of weight loss, disease activity index, macroscopic changes and histological damage of colon, along with lower levels of IL-1β and TNF-α. In vitro, rIL-38 significantly decreased the expression of proinflammatory cytokines in LPS-stimulated RAW 264.7 cells and BMDM. This is the first study suggesting that IL-38 may have a protective effect in IBD, which inhibits the production of proinflammatory cytokines from macrophages. IL-38 may represent a promising therapeutic strategy in IBD.

中文翻译：

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Interleukin-38 在炎症性肠病中升高并抑制肠道炎症

目前还没有关于 IL-38 在炎症性肠病 (IBD) 中的作用的报告。因此，我们研究了 IL-38 在 IBD 患者中的表达及其在调节肠道炎症中的作用。IBD 患者和 DSS 诱导的结肠炎小鼠肠道中 IL-38 的水平显着升高。免疫荧光分析显示，B 细胞，而不是巨噬细胞或 T 细胞，是肠道中 IL-38 的来源。我们发现 rIL-38 治疗显着减轻了 DSS 诱导的结肠炎，包括减轻体重减轻、疾病活动指数、结肠的宏观变化和组织学损伤，以及较低水平的 IL-1β 和 TNF-α。在体外，rIL-38 显着降低了 LPS 刺激的 RAW 264.7 细胞和 BMDM 中促炎细胞因子的表达。这是首次表明 IL-38 可能对 IBD 具有保护作用，从而抑制巨噬细胞产生促炎细胞因子。IL-38 可能代表 IBD 的一种有前途的治疗策略。