Chen Xu, Li Shi-Jun, Ojcius David M, Sun Ai-Hua, Hu Wei-Lin, Lin Xu'ai, Yan Jie
Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Zhejiang University, Hangzhou, Zhejiang, P.R. China.
Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China.
PLoS One. 2017 Jul 11;12(7):e0181014. doi: 10.1371/journal.pone.0181014. eCollection 2017.
To identify the major infiltrating phagocytes during leptospirosis and examine the killing mechanism used by the host to eliminate Leptospira interrogans.
Major infiltrating phagocytes in Leptospira-infected C3H/HeJ mice were detected by immunohistochemistry. Chemokines and vascular endothelial cell adhesion molecules (VECAMs) of Leptospira-infected mice and leptospirosis patients were detected by microarray and immunohistochemistry. Leptospira-phagocytosing and -killing abilities of human or mouse macrophages and neutrophils, and the roles of intracellular ROS, NO and [Ca2+]i in Leptospira-killing process were evaluated by confocal microscopy and spectrofluorimetry.
Peripheral blood mononuclear-macrophages rather than neutrophils were the main infiltrating phagocytes in the lungs, liver and kidneys of infected mice. Levels of macrophage- but not neutrophil-specific chemokines and VECAMs were significantly increased in the samples from infected mice and patients. All macrophages tested had a higher ability than neutrophils to phagocytose and kill leptospires. Higher ROS and NO levels and [Ca2+]i in the macrophages were involved in killing leptospires. Human macrophages displayed more phagolysosome formation and a stronger leptospire-killing ability to than mouse macrophages.
Mononuclear-macrophages but not neutrophils represent the main infiltrating and anti-leptospiral phagocytes during leptospirosis. A lower level of phagosome-lysosome fusion may be responsible for the lower Leptospira-killing ability of human macrophages.
鉴定钩端螺旋体病期间主要浸润的吞噬细胞，并研究宿主消除问号钩端螺旋体所采用的杀伤机制。
通过免疫组织化学检测感染钩端螺旋体的C3H/HeJ小鼠中的主要浸润吞噬细胞。通过微阵列和免疫组织化学检测感染钩端螺旋体的小鼠和钩端螺旋体病患者的趋化因子和血管内皮细胞黏附分子（VECAMs）。通过共聚焦显微镜和荧光分光光度法评估人或小鼠巨噬细胞和中性粒细胞吞噬和杀伤钩端螺旋体的能力，以及细胞内活性氧（ROS）、一氧化氮（NO）和细胞内钙离子浓度（[Ca2+]i）在钩端螺旋体杀伤过程中的作用。
外周血单核巨噬细胞而非中性粒细胞是感染小鼠肺、肝和肾中的主要浸润吞噬细胞。感染小鼠和患者样本中巨噬细胞而非中性粒细胞特异性趋化因子和VECAMs水平显著升高。所有测试的巨噬细胞吞噬和杀伤钩端螺旋体的能力均高于中性粒细胞。巨噬细胞中较高的ROS和NO水平以及[Ca2+]i参与了钩端螺旋体的杀伤。人巨噬细胞比小鼠巨噬细胞表现出更多的吞噬溶酶体形成和更强的钩端螺旋体杀伤能力。
单核巨噬细胞而非中性粒细胞是钩端螺旋体病期间主要的浸润和抗钩端螺旋体吞噬细胞。吞噬体-溶酶体融合水平较低可能是人类巨噬细胞钩端螺旋体杀伤能力较低的原因。
