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Updated: Dec 13, 2025
Isolation and Culture of Bone Marrow-Derived Macrophages from Mice
Published on: June 23, 2023
Establishment of bone marrow-derived M-CSF receptor-dependent self-renewing macrophages
Hesham Nasser1,2,3, Partho Adhikary1,2,4, Amira Abdel-Daim1,2
1Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, 860-0811 Japan.
Abstract:
Recent studies have revealed that tissue macrophages are derived from yolk sac precursors or fetal liver monocytes, in addition to bone marrow monocytes. The relative contribution of these cells to the tissue macrophage pool is not fully understood, but embryo-derived cells are supposed to be more important because of their capacity to self-renew. Here, we show the presence of adult bone marrow-derived macrophages that retain self-renewing capacity. The self-renewing macrophages were readily obtained by long-term culture of mouse bone marrow cells with macrophage colony-stimulating factor (M-CSF), a key cytokine for macrophage development. They were non-tumorigenic and proliferated in the presence of M-CSF in unlimited numbers. Despite several differences from non-proliferating macrophages, they retained many features of cells of the monocytic lineage, including the differentiation into dendritic cells or osteoclasts. Among the transcription factors involved in the self-renewal of embryonic stem cells, Krüppel-like factor 2 (KLF2) was strongly upregulated upon M-CSF stimulation in the self-renewing macrophages, which was accompanied by the downregulation of MafB, a transcription factor that suppresses KLF2 expression. Indeed, knockdown of KLF2 led to cell cycle arrest and diminished cell proliferation in the self-renewing macrophages. Our new cell model would be useful to unravel differences in phenotype, function, and molecular mechanism of proliferation among self-renewing macrophages with different origins.
Insights
Researchers discovered self-renewing macrophages derived from adult bone marrow. These cells, cultured with macrophage colony-stimulating factor (M-CSF), offer a new model for studying macrophage origins and functions.
Area of Science:
- Immunology
- Cell Biology
- Hematopoiesis
Background:
- Tissue macrophages originate from yolk sac, fetal liver, and bone marrow monocytes.
- Embryo-derived macrophages are thought to be more significant due to self-renewal capabilities.
- The self-renewing potential of adult bone marrow-derived macrophages remains less understood.
Purpose of the Study:
- To investigate the presence and characteristics of self-renewing macrophages from adult bone marrow.
- To establish a novel cell model for studying macrophage proliferation and differentiation.
- To explore the molecular mechanisms underlying macrophage self-renewal.
Main Methods:
- Long-term culture of mouse bone marrow cells with macrophage colony-stimulating factor (M-CSF).
- Assessment of macrophage proliferation, self-renewal, and differentiation potential (e.g., into dendritic cells, osteoclasts).
- Analysis of transcription factor expression, including Krüppel-like factor 2 (KLF2) and MafB, using knockdown experiments.
Main Results:
- Successfully generated non-tumorigenic, self-renewing macrophages from adult bone marrow in unlimited numbers with M-CSF.
- These macrophages maintained monocytic lineage features and differentiation capacity.
- Krüppel-like factor 2 (KLF2) upregulation and MafB downregulation were critical for M-CSF-induced self-renewal; KLF2 knockdown halted proliferation.
Conclusions:
- Adult bone marrow can yield self-renewing macrophages, challenging previous assumptions about embryonic origins.
- The established M-CSF-cultured macrophage model provides a valuable tool for investigating macrophage biology.
- KLF2 plays a crucial role in regulating the self-renewal of these bone marrow-derived macrophages.
