Related Experiment Video
Updated: Jun 5, 2026
Isolation of Cortical Microglia with Preserved Immunophenotype and Functionality From Murine Neonates
Published on: January 30, 2014
Bone marrow-derived microglia in pilocytic astrocytoma
Wafa AlShakweer1, Yazeed Alwelaie, Aaron M Mankung
1Division of Neuropathology, Department of Pathology and Clinical Laboratory Medicine, Faculty of Medicine, King Fahad Medical City, Riyadh, Kingdom of Saudi Arabia.
Abstract:
Tumour associated macrophages (TAMs) are increasingly recognized as supporters of tumour growth. The present study was undertaken to examine benign pilocytic astrocytomas (PAs) for the presence of M2 macrophages. We have asked the question whether TAMs in PAs share the predominant CD163 immunophenotype with tumour-associated microglia/macrophages of malignant gliomas. In addition, we were interested in the question whether there is evidence that the macrophages in PAs derive from resident microglia in surrounding normal brain or whether cells expressing a macrophage phenotype may invade PAs from the vasculature. The latter question is of great interest with regard to so-called "bone marrow-derived microglia" (BMDM) which may provide a physiological route of entry into the CNS that could be used for novel cell-based treatments of brain cancer. In fact, we have found strong morphological evidence for such macrophage recruitment into PAs. We propose therefore that PAs may be used as a model for the study of macrophage recruitment into gliomas. Importantly, our results also confirm that microglia/macrophage infiltration per se is not associated with malignant glioma behaviour.
Insights
Tumour-associated macrophages (TAMs) in pilocytic astrocytomas (PAs) exhibit M2 markers. Macrophage recruitment into PAs suggests a model for studying glioma infiltration.
Area of Science:
- Neuro-oncology
- Immunology
- Cell Biology
Background:
- Tumour-associated macrophages (TAMs) are increasingly recognized for their role in supporting tumor growth.
- Malignant gliomas feature tumour-associated microglia/macrophages (TAMs) with a predominant CD163 immunophenotype.
Purpose of the Study:
- To investigate the presence and phenotype of M2 macrophages in benign pilocytic astrocytomas (PAs).
- To determine if TAMs in PAs share the CD163 immunophenotype with those in malignant gliomas.
- To explore the origin of macrophages in PAs, differentiating between resident microglia and vasculature-derived cells.
Main Methods:
- Immunohistochemical analysis of pilocytic astrocytoma (PA) tissue samples.
- Morphological assessment to identify macrophage infiltration and origin.
Main Results:
- Strong morphological evidence suggests macrophage recruitment into pilocytic astrocytomas (PAs) from the vasculature.
- Pilocytic astrocytomas (PAs) show the presence of M2 macrophages.
- Microglia/macrophage infiltration alone does not correlate with malignant glioma behavior.
Conclusions:
- Pilocytic astrocytomas (PAs) serve as a valuable model for studying macrophage recruitment into gliomas.
- Macrophage infiltration into the central nervous system (CNS) via vasculature is supported by findings in PAs.
- The study confirms that microglia/macrophage infiltration is not inherently linked to malignant glioma progression.
