Related Experiment Video
Updated: Aug 15, 2026
Busulfan as a Myelosuppressive Agent for Generating Stable High-level Bone Marrow Chimerism in Mice
Published on: April 1, 2015
Macrophage function in murine allogeneic bone marrow radiation chimeras in the early phase after transplantation
J Roesler1, M Baccarini, B Vogt
1Department of Immunobiology, Fraunhofer-Institute for Toxicology and Aerosol Research, Hannover, Federal Republic of Germany.
Abstract:
We tested several of the functions of macrophages (M phi) in the early phase after allogeneic bone marrow transfer to get information about this important aspect of the nonspecific immune system in the T-cell-deficient recipient. On days 3-5 after transfer, the number of M phi was reduced in the spleen, liver, lungs, and peritoneal cavity (Pe). The phagocytosis of sheep red blood cells (SRBC) by these M phi was normal or even enhanced, as in the case of Pe-M phi. Already on days 8-12 after transfer, the number of M phi in spleen and liver exceeded that of controls, whereas the number was still reduced in lungs and Pe. We examined their ability to kill P815 tumor cells, to produce tumor necrosis factor-alpha (TNF alpha), to phagocytose SRBC, to produce reactive oxygen intermediates (ROI) in vitro and to kill Listeria monocytogenes in vivo. Most functions were normal and often even enhanced, depending on the organ origin, but the ability of Pe-M phi to produce ROI was reduced. Proliferative response to macrophage colony-stimulating factor (M-CSF) and killing of YAC-1 tumor cells revealed a high frequency of macrophage precursor cells in the spleen and liver and a high natural killer (NK) activity in the liver. Altogether, enhanced nonspecific immune function, especially preactivated M phi, may enable chimeras to survive attacks by opportunistic pathogens.
Insights
Macrophages (M phi) show altered numbers and enhanced functions post-bone marrow transfer, indicating improved nonspecific immunity in T-cell-deficient recipients against opportunistic pathogens.
Area of Science:
- Immunology
- Hematology
- Cell Biology
Background:
- Macrophages (M phi) are crucial for the nonspecific immune system.
- Allogeneic bone marrow transfer is a procedure involving the transplantation of hematopoietic stem cells.
- T-cell-deficient recipients have a compromised adaptive immune system.
Purpose of the Study:
- To investigate macrophage functions in the early phase after allogeneic bone marrow transfer.
- To understand the role of macrophages in the nonspecific immune system of T-cell-deficient recipients.
Main Methods:
- Assessing macrophage numbers in spleen, liver, lungs, and peritoneal cavity.
- Evaluating phagocytosis of sheep red blood cells (SRBC).
- Testing tumor cell killing, TNF-alpha production, ROI production, and Listeria monocytogenes killing.
- Analyzing proliferative response to M-CSF and NK activity.
Main Results:
- Macrophage numbers initially decreased but later increased in spleen and liver.
- Phagocytosis and most other macrophage functions were normal or enhanced.
- Reduced ROI production was observed in peritoneal macrophages.
- High frequencies of macrophage precursors and NK activity were found in spleen and liver.
Conclusions:
- Enhanced nonspecific immune function, particularly preactivated macrophages, may improve survival against opportunistic pathogens in bone marrow transplant recipients.
- Macrophage precursor cells and NK cells contribute to early immune reconstitution.
