Podder Biswajit, Jang Woong Sik, Nam Kung-Woo, Lee Byung-Eui, Song Ho-Yeon
Department of Microbiology and Immunology, School of Medicine, Soonchunhyang University, Cheonan 330-090, Republic of Korea.
Regional Innovation Center, Soonchunhyang University, Asan 336-745, Republic of Korea.
J Microbiol Biotechnol. 2015 May;25(5):738-44. doi: 10.4014/jmb.1407.07020.
Tuberculosis is one of the most threatening infectious diseases to public health all over the world, for which Mycobacterium tuberculosis (MTB) is the etiological agent of pathogenesis. Ursolic acid (UA) has immunomodulatory function and exhibits antimycobacterial activity. However, the intracellular killing effect of UA has yet to be elucidated. The aim of this study was to evaluate the intracellular killing effect of UA during mycobacterial infection. The intracellular killing activity of UA was evaluated in the macrophage cell line THP-1 by the MGIT 960 system as well as by CFU count. The production of reactive oxygen species (ROS) and the level of nitric oxide (NO) were measured using DCF-DA and Griess reagent, respectively. Phagocytosis was observed by a fluorescence-based staining method, and the colony forming units were enumerated on 7H11 agar medium following infection. In addition, MRP8 mRNA expression was measured by qRT-PCR. UA significantly decreased the number of intracellular Mycobacterium through generation of ROS and NO. In addition, it profoundly activated the phagocytosis process of THP-1 cells during MTB-infection. Furthermore, our data demonstrated that UA activated the phagocytosis process in human monocyte cells through MRP8 induction. These data suggest that UA firmly contributes to the intracellular killing effect of macrophages during mycobacterial infection.
结核病是全球对公共卫生威胁最大的传染病之一，结核分枝杆菌（MTB）是其致病病原体。熊果酸（UA）具有免疫调节功能并表现出抗分枝杆菌活性。然而，UA的细胞内杀伤作用尚未阐明。本研究的目的是评估UA在分枝杆菌感染期间的细胞内杀伤作用。通过MGIT 960系统以及CFU计数在巨噬细胞系THP-1中评估UA的细胞内杀伤活性。分别使用DCF-DA和格里斯试剂测量活性氧（ROS）的产生和一氧化氮（NO）的水平。通过基于荧光的染色方法观察吞噬作用，并在感染后在7H11琼脂培养基上计数菌落形成单位。此外，通过qRT-PCR测量MRP8 mRNA表达。UA通过产生ROS和NO显著减少细胞内分枝杆菌的数量。此外，它在MTB感染期间深刻激活了THP-1细胞的吞噬过程。此外，我们的数据表明UA通过诱导MRP8激活人单核细胞中的吞噬过程。这些数据表明UA在分枝杆菌感染期间对巨噬细胞的细胞内杀伤作用有重要贡献。
