Optimization of a neuron-microglia co-culture model to explore cell-to-cell interaction dynamics

Area of Science:

• Neuroscience
• Immunology
• Cell Biology

Background:

• The central nervous system (CNS) involves complex immune-nervous system interactions.
• Microglia, the brain's immune cells, are crucial for homeostasis, development, and injury response.
• Understanding neuron-microglia communication is vital for neuroimmunology.

Purpose of the Study:

• To establish a reproducible *in vitro* model for studying neuron-microglia interactions.
• To characterize induced microglia-like cells (iMGs) derived from human embryonic stem cells (hESCs).
• To investigate the bidirectional communication between iMGs and induced neurons (iNeus).

Main Methods:

• Generated iMGs from hESCs using CEBPA/SPI1 transcription factor overexpression.
• Characterized iMGs via microglial markers, phagocytosis assays, and scanning electron microscopy (SEM).
• Co-cultured iMGs with hESC-derived iNeus, optimizing seeding ratios and temporal parameters.

Main Results:

• iMGs expressed key microglial markers and showed comparable phagocytic ability to HMC3 cells.
• Co-cultured iMGs displayed phenotypic plasticity, upregulating homeostatic and activation genes.
• Neurons showed increased maturation and synaptic markers, indicating bidirectional crosstalk; iMG morphology varied with neuronal proximity.

Conclusions:

• The developed contact-based *in vitro* system offers a versatile platform for neuroimmune research.
• This model facilitates studies on microglial activation, neuron-microglia signaling, and CNS infection impacts.
• The system is adaptable for integrating additional CNS cell types for more complex modeling.