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Updated: Aug 4, 2025
Rapid and Refined CD11b Magnetic Isolation of Primary Microglia with Enhanced Purity and Versatility
Published on: April 13, 2017
A richer and more diverse future for microglia phenotypes
Jie Wang1, Wenbin He2, Junlong Zhang1,2
1College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan 250000, Shandong, China.
Abstract:
Microglia are the only resident innate immune cells derived from the mesoderm in the nerve tissue. They play a role in the development and maturation of the central nervous system (CNS). Microglia mediate the repair of CNS injury and participate in endogenous immune response induced by various diseases by exerting neuroprotective or neurotoxic effects. Traditionally, microglia are considered to be in a resting state, the M0 type, under physiological conditions. In this state, they perform immune surveillance by constantly monitoring pathological responses in the CNS. In the pathological state, microglia undergo a series of morphological and functional changes from the M0 state and eventually polarize into classically activated microglia (M1) and alternatively activated microglia (M2). M1 microglia release inflammatory factors and toxic substances to inhibit pathogens, while M2 microglia exert neuroprotective effects by promoting nerve repair and regeneration. However, in recent years, the view regarding M1/M2 polarization of microglia has gradually changed. According to some researchers, the phenomenon of microglia polarization is not yet confirmed. The M1/M2 polarization term is used for a simplified description of its phenotype and function. Other researchers believe that the microglia polarization process is rich and diverse, and consequently, the classification method of M1/M2 has limitations. This conflict hinders the academic community from establishing more meaningful microglia polarization pathways and terms, and therefore, a careful revision of the concept of microglia polarization is required. The present article briefly reviews the current consensus and controversy regarding microglial polarization typing to provide supporting materials for a more objective understanding of the functional phenotype of microglia.
Insights
Microglia, the brain's immune cells, traditionally polarize into M1 and M2 types. However, recent research questions this simplified model, highlighting the need for a revised understanding of microglial function.
Area of Science:
- Neuroscience
- Immunology
- Cell Biology
Background:
- Microglia are the primary innate immune cells in the central nervous system (CNS).
- They are crucial for CNS development, injury repair, and immune responses.
- Traditionally, microglia are classified as M0 (resting), M1 (pro-inflammatory), and M2 (anti-inflammatory/repair) phenotypes.
Purpose of the Study:
- To review the current consensus and controversies surrounding microglial polarization typing.
- To provide a basis for a more objective understanding of microglial functional phenotypes.
- To address the limitations of the M1/M2 polarization model.
Main Methods:
- Literature review of existing research on microglial polarization.
- Analysis of conflicting viewpoints on microglial phenotype classification.
- Discussion of the implications for understanding microglial function in health and disease.
Main Results:
- The traditional M1/M2 microglia polarization model is increasingly debated.
- Some researchers question the confirmation of distinct M1/M2 polarization phenomena.
- The M1/M2 classification is considered a simplification with inherent limitations.
Conclusions:
- A critical revision of the concept of microglial polarization is necessary.
- The diversity and complexity of microglial responses challenge simple M1/M2 categorization.
- Further research is needed to establish more accurate models of microglial functional states.
