Guo Shu-Xuan, Jiang Nan, Zhang Li, Jiang Wei, Ma Jing-Jing
Qingdao University, Qingdao 266003, Shandong Province, China.
Int J Ophthalmol. 2022 Mar 18;15(3):380-387. doi: 10.18240/ijo.2022.03.02. eCollection 2022.
To explore the effect of indoleamine 2,3-dioxygenase (IDO) on recruitment and chemotaxis function of neutrophils in keratitis.
C57BL/6 mice models of keratitis were established by inoculating hyphae of evenly on the corneas. The clinical scores and inflammatory cytokines expression were measured respectively on the 1, 3, 5 day after infection. The 1-MT (1 mg/mL) was administered by gavage to exert an inhibitory effect on IDO during infection. The mice were divided into control group, 1-MT group, (A.F.) group, and 1-MT+A.F. groups. The corneas were monitored by slit lamp microscopy, and recorded disease scores in 3d after infection. Myeloperoxidase (MPO) assay was done to evaluate the neutrophils infiltration. Immunofluorescence staining was used to detect the recruitment of neutrophils in murine corneas. The mRNA of inflammatory cytokines was measured with reverse transcription-polymerase chain reaction (RT-PCR).
The corneal inflammation and the clinical score reached the peak on the 3 day after the corneal infection. The mRNA of inflammatory cytokines of the A.F. group reached the highest on the 3 day after the infection accordingly. Meanwhile, the results of slit light photography indicated that inhibitors of IDO made inflammation more serious contrasted with the A.F. group on the 3 day. Besides, imunofluorescence staining and MPO indicated that 1-MT enhanced the recruitment, infiltration and chemotaxis of neutrophils obviously in contrast to the A.F. group. RT-PCR indicated that 1-MT increased the expression of CXCL-1, ICAM-1, IL-1β, and IL-8 significantly.
IDO participates in the pathogenesis of keratitis and plays an important role in inducing immune protection by inhibiting neutrophils-related inflammatory reaction and suppressing recruitment and chemotaxis of the neutrophils.
探讨吲哚胺2,3-双加氧酶（IDO）在角膜炎中对中性粒细胞募集及趋化功能的影响。
通过将菌丝均匀接种于角膜建立C57BL/6小鼠角膜炎模型。分别在感染后第1、3、5天测量临床评分及炎性细胞因子表达。在感染期间通过灌胃给予1-MT（1 mg/mL）以对IDO发挥抑制作用。将小鼠分为对照组、1-MT组、烟曲霉菌（A.F.）组和1-MT+A.F.组。用裂隙灯显微镜监测角膜情况，并记录感染后3天的疾病评分。进行髓过氧化物酶（MPO）检测以评估中性粒细胞浸润情况。采用免疫荧光染色检测小鼠角膜中中性粒细胞的募集情况。用逆转录-聚合酶链反应（RT-PCR）检测炎性细胞因子的mRNA。
角膜感染后第3天角膜炎症及临床评分达到峰值。相应地，A.F.组炎性细胞因子的mRNA在感染后第3天达到最高水平。同时，裂隙灯摄影结果表明，与A.F.组相比，IDO抑制剂在第3天使炎症更严重。此外，免疫荧光染色和MPO检测表明，与A.F.组相比，1-MT明显增强了中性粒细胞的募集、浸润及趋化作用。RT-PCR表明，1-MT显著增加了CXCL-1、ICAM-1、IL-1β和IL-8的表达。
IDO参与角膜炎的发病机制，通过抑制中性粒细胞相关炎症反应及抑制中性粒细胞的募集和趋化作用在诱导免疫保护中发挥重要作用。
