Migrating Lung Monocytes Internalize and Inhibit Growth of Aspergillus fumigatus Conidia
Natalia Schiefermeier-Mach1, Thomas Haller2, Stephan Geley3
1Health University of Applied Sciences Tyrol/FH Gesundheit Tirol, Innrain 98, 6020 Innsbruck, Austria.
Abstract:
Monocytes are important players to combat the ubiquitously present fungus Aspergillus fumigatus. Recruitment of monocytes to sites of fungal A. fumigatus infection has been shown in vivo. Upon exposure to A. fumigatus in vitro, purified murine and human blood monocytes secrete inflammatory cytokines and fungicidal mediators. Mononuclear tissue phagocytes are phenotypically and functionally different from those circulating in the blood and their role in antifungal defenses is much less understood. In this study, we identified a population of migrating CD43 monocytes in cells isolated from rat distal lungs. These cells are phenotypically different from alveolar macrophages and show distinct locomotory behavior on the surface of primary alveolar cells resembling previously described endothelial patrolling monocytes. Upon challenge, the CD43 monocytes internalized A. fumigatus conidia resulting in inhibition of their germination and hyphal growth. Thus, migrating lung monocytes might play an important role in local defense against pulmonary pathogens.
Insights
Migrating lung monocytes (CD43+) effectively combat Aspergillus fumigatus by internalizing fungal spores, inhibiting their growth. These cells represent a key component of local pulmonary defense against fungal infections.
Area of Science:
- Immunology
- Mycology
- Pulmonary Medicine
Background:
- Monocytes are crucial for fighting Aspergillus fumigatus infections.
- Blood monocytes secrete inflammatory and fungicidal mediators upon A. fumigatus exposure.
- The role of tissue-resident mononuclear phagocytes in antifungal defense is less understood.
Purpose of the Study:
- To identify and characterize lung-resident monocytes involved in antifungal defense.
- To investigate the function of these monocytes against Aspergillus fumigatus.
Main Methods:
- Isolation of migrating CD43+ monocytes from rat distal lungs.
- Phenotypic and functional characterization of these monocytes.
- Assessment of their interaction with Aspergillus fumigatus conidia in vitro.
Main Results:
- A distinct population of migrating CD43+ monocytes was identified in rat lungs.
- These monocytes exhibited different phenotypes and behaviors compared to alveolar macrophages.
- CD43+ monocytes internalized A. fumigatus conidia, preventing germination and hyphal growth.
Conclusions:
- Migrating lung monocytes (CD43+) play a significant role in local pulmonary defense against Aspergillus fumigatus.
- These cells contribute to antifungal immunity by phagocytosing and controlling fungal pathogens.
- Further research into lung monocyte function is warranted for understanding pulmonary antifungal defenses.
