Accelerating Functional Maturation of Human iPSC-Derived Microglia

Project Summary/AbstractNeurological and psychiatric disorders, including Alzheimer’s disease (AD), exert a devastating personal and economic toll on patients, families, caregivers, and society. This is in part due to our failure to develop effective medications, reflecting drug discovery platforms that are often not relevant to target diseases. The recent development of induced pluripotent stem cells (iPSCs) from humans makes it possible to screen and validate candidate compounds on human brain cells, including those from patients, thus potentially increasing the success rate and speeding the pace of CNS drug development.BrainXell, Inc. has pioneered the development of human patient brain cell-based platforms for CNS drug discovery. We are able to produce large quantities of highly enriched microglia of consistent quality from human iPSCs through our platform technology of directed differentiation and expansion of committed progenitors. However, iPSC-derived microglia are immature, comparable to those at the fetal stage, which makes it difficult for presentation of disease phenotypes and for high-throughput screening (HTS) for drug leads intended for those whose brains are fully mature. The goal of this Phase I SBIR project is to uncover molecules that speed the expression of genes associated with a mature state in iPSC-derived microglia and to formulate cocktails that yield mature microglia within 1-3 weeks after plating. We will engineer a human iPSC reporter line with nanoluciferase (Nluc) fused to P2RY12, a purinergic receptor highly expressed in mature microglia. This line will enable and simplify the screening of small molecules for accelerating microglia maturation. Formulation of an effective cocktail for rapidly generating mature human microglia will remove a major roadblock in establishing human patient microglia-based HTS for CNS drug development.Project NarrativeBrainXell will develop technology to accelerate the maturation of human stem cell-derived immune cells that reside in the brain. These cells will enable more predictive drug screening on a large scale, thus aiding in the discovery of new drugs for treating neurodegenerative disorders such as Alzheimer’s disease.