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Invest Ophthalmol Vis Sci. 2020 Jul 1;61(8):28. doi: 10.1167/iovs.61.8.28.
To explore the influence of indoleamine 2,3-dioxygenase (IDO) on macrophage recruitment, polarization and phagocytosis in Aspergillus fumigatus keratitis.
A murine model of A. fumigatus keratitis and peritoneal macrophages incubated with the hyphae of A. fumigatus were used. Macrophage recruitment in corneas was evaluated using immunofluorescence staining. The polarization of macrophages, which was stimulated by A. fumigatus and pretreatment with or without 1-methyltryptophan (1-MT), interferon gamma (IFNG), extracellular regulated protein kinases (ERK) antagonist, and p38 antagonist, was determined using reverse-transcription polymerase chain reaction and flow cytometry. P38 and ERK levels were determined using Western blotting. Macrophage phagocytosis was examined using colony-forming units.
Compared with the A.F. group, recruitment of macrophages increased, tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) expression decreased, whereas arginase-1 (Arg-1) and interleukin-10 (IL-10) expression increased in the mouse corneas of the 1-MT+A.F. group. The ratio of CD206+/CD86+ macrophages in the corneas and spleens of 1-MT+A.F. group increased. Furthermore, in peritoneal macrophages stimulated by A. fumigatus, 1-MT promoted Arg-1 and IL-10 expression while upregulating the ratio of CD206+/CD86+ macrophages. Conversely, IDO agonist IFNG promoted TNF-α and iNOS expression, inhibited Arg-1 and IL-10 expression and downregulated the ratio of CD206+/CD86+ macrophages. The role of IFNG was reversed by the antagonist of P38 or ERK. P38 and ERK levels were downregulated in corneas of 1-MT+A.F. group. Besides, IFNG inhibited macrophage phagocytosis.
IDO inhibited macrophage recruitment and phagocytosis in A. fumigatus keratitis. Mechanistically, IDO is involved in M1 macrophage polarization in A. fumigatus keratitis through a MAPK/ERK-dependent pathway.
探讨色氨酸 2,3-双加氧酶（IDO）对烟曲霉菌角膜炎中巨噬细胞募集、极化和吞噬作用的影响。
采用烟曲霉菌角膜炎小鼠模型和与烟曲霉菌菌丝共孵育的腹腔巨噬细胞。通过免疫荧光染色评估角膜中巨噬细胞的募集情况。用烟曲霉菌刺激并预先用 1-甲基色氨酸（1-MT）、干扰素γ（IFNG）、细胞外调节蛋白激酶（ERK）拮抗剂和 p38 拮抗剂处理后，通过逆转录聚合酶链反应和流式细胞术测定巨噬细胞的极化情况。用 Western blot 测定 p38 和 ERK 水平。用集落形成单位测定巨噬细胞吞噬作用。
与 A.F.组相比，1-MT+A.F.组小鼠角膜中巨噬细胞募集增加，肿瘤坏死因子-α（TNF-α）和诱导型一氧化氮合酶（iNOS）表达减少，而精氨酸酶-1（Arg-1）和白细胞介素-10（IL-10）表达增加。1-MT+A.F.组角膜和脾脏中 CD206+/CD86+巨噬细胞的比例增加。此外，在烟曲霉菌刺激的腹腔巨噬细胞中，1-MT 促进 Arg-1 和 IL-10 表达，同时上调 CD206+/CD86+巨噬细胞的比例。相反，IDO 激动剂 IFNG 促进 TNF-α 和 iNOS 表达，抑制 Arg-1 和 IL-10 表达，并下调 CD206+/CD86+巨噬细胞的比例。P38 或 ERK 拮抗剂可逆转 IFNG 的作用。1-MT+A.F.组角膜中 p38 和 ERK 水平下调。此外，IFNG 抑制巨噬细胞吞噬作用。
IDO 抑制烟曲霉菌角膜炎中巨噬细胞的募集和吞噬作用。机制上，IDO 通过 MAPK/ERK 依赖途径参与烟曲霉菌角膜炎中 M1 巨噬细胞极化。
