Abstract
Objective: To identify the major infiltrating phagocytes during leptospirosis and examine the killing mechanism used by the host to eliminate Leptospira interrogans. Methods: 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. Results: 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. Conclusions: 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.
Original language | English |
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Article number | e0181014 |
Journal | PLoS ONE |
Volume | 12 |
Issue number | 7 |
DOIs | |
State | Published - 07 2017 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2017 Chen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the originalauthor and source are credited.