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Updated: Jul 5, 2026
In vitro Quantitative Imaging Assay for Phagocytosis of Dead Neuroblastoma Cells by iPSC-Macrophages
Published on: February 14, 2021
End-stage dying glioma cells are engulfed by mouse microglia with a strain-dependent efficacy
Dorothee Nickles1, Anette Abschuetz, Heiko Zimmer
1INSERM U701, German Cancer Research Centre, Program Infection and Cancer, INF 242, 69120 Heidelberg, Germany.
Abstract:
Microglia phagocytic activity for apoptotic glioma cells is hardly analysed inspite of its relevance to tissue damage prevention. We provide evidence for a phosphatidylserine-independent clearance of mouse glioma cells at an advanced stage of death, suggesting microglia recognition of late apoptotic markers. Dying cells were immediately cleared or stayed for hours in that stage before engulfment occurred. This phagocytic activity was restricted to a microglia subset representing 30 to 70% of the population according to the used strain. Expression of receptors involved in late apoptotic markers recognition therefore seems confined to a subpopulation of microglia and to be strain-dependent.
Insights
Microglia engulf late-stage apoptotic glioma cells independently of phosphatidylserine. This phagocytic activity is specific to a subset of microglia and varies by mouse strain, suggesting strain-dependent recognition of late apoptotic markers.
Area of Science:
- Neuroscience
- Immunology
- Oncology
Background:
- Microglia play a crucial role in brain homeostasis and disease.
- Glioma is a primary brain tumor with significant morbidity.
- The phagocytic clearance of apoptotic glioma cells by microglia is not well understood.
Purpose of the Study:
- To investigate the mechanisms and characteristics of microglia phagocytosis of late-stage apoptotic glioma cells.
- To determine if phosphatidylserine is a necessary recognition marker for this process.
- To identify the subset of microglia involved and assess strain-dependent variations.
Main Methods:
- Utilized in vitro co-culture systems with mouse glioma cells and primary microglia.
- Observed phagocytosis using live-cell imaging and quantified engulfment.
- Analyzed the expression of relevant receptors on microglia populations.
- Compared phagocytic activity across different mouse strains.
Main Results:
- Microglia demonstrated phosphatidylserine-independent clearance of late apoptotic glioma cells.
- Glioma cells were cleared either immediately or after a delay, indicating recognition of late apoptotic markers.
- Phagocytic activity was confined to a specific subset of microglia, ranging from 30% to 70% of the population.
- The extent of phagocytosis and receptor expression showed significant strain-dependent differences.
Conclusions:
- Microglia recognize and clear late apoptotic glioma cells via a phosphatidylserine-independent pathway.
- This phagocytic process involves specific microglia subpopulations and is influenced by mouse strain.
- Findings suggest strain-specific expression of receptors for late apoptotic markers on microglia, impacting glioma clearance.
