Basic Science and Pathogenesis.

Area of Science:

• Neuroscience
• Stem Cell Biology
• Immunology

Background:

• Induced pluripotent stem cell (iPSC) technology allows for the creation of human microglia-like cells (iMG) in vitro.
• A novel iPSC line, IBRI 104.G, was utilized for iMG differentiation.
• The study evaluated the functional and biochemical characteristics of the iMG model.

Purpose of the Study:

• To differentiate and characterize iPSC-derived microglia-like cells (iMG).
• To assess iMG responses to immunogenic stimuli like myelin debris and amyloid-beta (Aβ) oligomers.
• To investigate the effects of anti-amyloid and TREM2-targeting antibodies on iMG biology.

Main Methods:

• Generation of the IBRI 104.G iPSC line using episomal reprogramming vectors.
• Differentiation of iMG on matrigel-coated plates.
• Preparation of myelin debris from mouse brains and Aβ oligomers from recombinant peptides.
• Production of TREM2 and Aβ antibodies via CHO cell transfection.
• High-content fluorescent imaging to analyze microglia morphology and phagocytosis.

Main Results:

• The IBRI 104.G iPSC line expressed pluripotent markers; differentiated iMG expressed key microglia markers (PU.1, P2RY12R, TMEM119, TREM2).
• iMG exhibited ramified morphology, becoming ameboid upon inflammatory stimulation, and demonstrated phagocytosis of myelin debris and Aβ.
• TREM2 antibodies decreased myelin phagocytosis, while Aβ antibodies enhanced amyloid uptake by iMG.

Conclusions:

• The IBRI 104.G iPSC line efficiently differentiates into microglia-like cells with human microglia characteristics.
• iMG serve as a valuable in vitro model for studying neuroinflammation and testing therapeutic antibodies targeting brain myeloid cells.