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Updated: May 23, 2025
Assessing Anti-fungal Activity of Isolated Alveolar Macrophages by Confocal Microscopy
Published on: July 9, 2014
Targeted labeling and depletion of alveolar macrophages using VeDTR mouse technology
Yuki Nakayama1,2, Miwa Sasai1,2,3,4, Ayumi Kuratani1,2
1Department of Immunoparasitology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.
Abstract:
Alveolar macrophages (AMs) are essential for maintaining lung homeostasis. However, their roles in respiratory infections have been controversial because the methods of depleting them have often suffered from poor cell selectivity. To resolve this problem, we here used VeDTR technology to generate a transgenic mouse line in which AMs can be specifically depleted using diphtheria toxin. When various respiratory infections were examined using this system, we found that AMs prevented the proliferation of Mycobacterium abscessus. This result differed from previous findings using clodronate liposomes to deplete macrophages. We also revealed that the disappearance of AMs contributes to the reduction of bacterial load in the lungs and that AMs are indispensable for GM-CSF-mediated defense against M. abscessus infection. Taken together, the development of an AM-specific depletion system has provided an opportunity to study the roles of AMs in various respiratory infections from a different perspective.
Insights
Alveolar macrophages (AMs) are crucial for lung health but their role in infections was unclear. Using a new method to specifically remove AMs, researchers found they prevent Mycobacterium abscessus growth and are vital for lung defense.
Area of Science:
- Immunology
- Pulmonology
- Microbiology
Background:
- Alveolar macrophages (AMs) are key to lung homeostasis.
- Previous studies on AMs' role in infections were limited by non-specific depletion methods.
Purpose of the Study:
- To develop a specific method for depleting AMs to clarify their function in respiratory infections.
- To investigate the role of AMs in Mycobacterium abscessus infection.
Main Methods:
- Generated a transgenic mouse line using VeDTR technology for diphtheria toxin-induced AM depletion.
- Studied the effects of AM depletion on various respiratory infections, focusing on M. abscessus.
Main Results:
- AMs were found to prevent the proliferation of Mycobacterium abscessus, contrary to previous findings.
- Depletion of AMs led to reduced bacterial load in the lungs.
- AMs are essential for GM-CSF-mediated defense against M. abscessus infection.
Conclusions:
- The development of an AM-specific depletion system allows for a clearer understanding of AM roles in lung infections.
- AMs play a critical protective role against M. abscessus infection.
