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Updated: Aug 15, 2026
Bone Marrow-derived Macrophage Production
Published on: November 22, 2013
Effects of macrophage-CSF on pulmonary-macrophage repopulation after bone marrow transplantation
T Bernier1, T Tschernig, R Pabst
1Department of Immunobiology, Fraunhofer Institute of Toxicology and Aerosol Research, 30625 Hannover, Germany.
Abstract:
Pulmonary infections are important causes of morbidity and mortality in immunosuppressed patients after transplantation. After experimental irradiation and syngeneic bone marrow transplantation in mice, macrophages show reduced repopulation in the lung compared with that in other tissues. Macrophages are major microbicidal immune effector cells in host pulmonary defense. Therefore, we examined the role of locally applied cytokines for macrophage repopulation in the lung. An accelerated repopulation of macrophages in the lung was observed after intranasal application of macrophage-colony stimulating factor (M-CSF), but this effect was not enhanced by a combination of M-CSF with interleukin (IL)-3. Local proliferation contributed to this effect. Macrophages in the lung tissue of M-CSF-treated mice displayed greater secretion of IL-6, whereas M-CSF treatment did not enhance the gene expression of other macrophage-specific chemokines. The role of M-CSF treatment was determined in pulmonary murine cytomegalovirus infection using an irradiation/reconstitution model. The M-CSF treatment had no effect on virus load in the lung tissue. However, phosphate-buffered saline-treated mice seemed to develop stronger inflammation after viral infection than M-CSF-treated mice. We conclude that local M-CSF treatment modulates cellular inflammation in the lung during immunosuppression.
Insights
Local application of macrophage-colony stimulating factor (M-CSF) accelerates lung macrophage repopulation in immunosuppressed mice. M-CSF modulated inflammation during cytomegalovirus infection, highlighting its role in pulmonary defense.
Area of Science:
- Immunology
- Transplantation Medicine
- Pulmonary Medicine
Background:
- Pulmonary infections pose significant risks for immunosuppressed transplant patients.
- Macrophages are crucial for lung immunity but repopulate slowly post-transplant.
- Understanding macrophage dynamics is key to improving post-transplant outcomes.
Purpose of the Study:
- To investigate the effect of local cytokines on macrophage repopulation in the lung.
- To determine if macrophage-colony stimulating factor (M-CSF) can enhance lung macrophage recovery.
- To assess the impact of M-CSF on pulmonary infection and inflammation.
Main Methods:
- Irradiation and syngeneic bone marrow transplantation in a murine model.
- Intranasal administration of macrophage-colony stimulating factor (M-CSF) and interleukin-3 (IL-3).
- Analysis of macrophage repopulation, cytokine secretion (IL-6), gene expression, and viral load (murine cytomegalovirus).
Main Results:
- Intranasal M-CSF accelerated lung macrophage repopulation through local proliferation.
- M-CSF treatment increased IL-6 secretion by lung macrophages but not other chemokines.
- M-CSF did not affect viral load but reduced inflammation in a murine cytomegalovirus infection model.
Conclusions:
- Local M-CSF administration effectively promotes lung macrophage repopulation post-transplantation.
- M-CSF modulates pulmonary inflammation during immunosuppression and infection.
- Targeting M-CSF may be a therapeutic strategy for managing lung complications in transplant recipients.
