2. Academic Validation
  3. Engineering an inhibitor-resistant human CSF1R variant for microglia replacement

Engineering an inhibitor-resistant human CSF1R variant for microglia replacement

  • J Exp Med. 2023 Mar 6;220(3):e20220857. doi: 10.1084/jem.20220857.
Jean Paul Chadarevian # 1 2 3,  Sonia I Lombroso # 4 5 6,  Graham C Peet 4 7,  Jonathan Hasselmann 1 3,  Christina Tu 2 3,  Dave E Marzan 8,  Joia Capocchi 2,  Freddy S Purnell 4,  Kelsey M Nemec 4 9,  Alina Lahian 2 3,  Adrian Escobar 3,  Whitney England 10,  Sai Chaluvadi 4 9,  Carleigh A O'Brien 4,  Fazeela Yaqoob 4,  William H Aisenberg 4,  Matias Porras-Paniagua 11,  Mariko L Bennett 9 12,  Hayk Davtyan 2 3,  Robert C Spitale 10,  Mathew Blurton-Jones # 1 2 3,  F Chris Bennett # 4 12
Affiliations

Affiliations

  • 1 Department of Neurobiology & Behavior, University of California, Irvine , Irvine, CA, USA.
  • 2 Institute for Memory Impairments and Neurological Disorders, University of California, Irvine , Irvine, CA, USA.
  • 3 Sue and Bill Gross Stem Cell Research Center, University of California, Irvine , Irvine, CA, USA.
  • 4 Department of Psychiatry, Perelman School of Medicine , University of Pennsylvania, Philadelphia, PA, USA.
  • 5 Pharmacology Graduate Group, Biomedical Graduate Studies Program, University of Pennsylvania , Philadelphia, PA, USA.
  • 6 Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania , Philadelphia, PA, USA.
  • 7 Neuroscience Graduate Program and Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus , Aurora, CO, USA.
  • 8 Department of Biology, The College of New Jersey , Ewing, NJ, USA.
  • 9 Department of Neuroscience, Perelman School of Medicine , Philadelphia, PA, USA.
  • 10 Department of Pharmaceutical Sciences, University of California, Irvine , Irvine, CA, USA.
  • 11 Department of Bioengineering, University of Pennsylvania , Philadelphia, PA, USA.
  • 12 Division of Neurology, Children's Hospital of Philadelphia , Philadelphia, PA, USA.
  • # Contributed equally.
PMID: 36584406 DOI: 10.1084/jem.20220857
Abstract

Hematopoietic stem cell transplantation (HSCT) can replace endogenous microglia with circulation-derived macrophages but has high mortality. To mitigate the risks of HSCT and expand the potential for microglia replacement, we engineered an inhibitor-resistant CSF1R that enables robust microglia replacement. A glycine to alanine substitution at position 795 of human CSF1R (G795A) confers resistance to multiple CSF1R inhibitors, including PLX3397 and PLX5622. Biochemical and cell-based assays show no discernable gain or loss of function. G795A- but not wildtype-CSF1R expressing macrophages efficiently engraft the brain of PLX3397-treated mice and persist after cessation of inhibitor treatment. To gauge translational potential, we CRISPR engineered human-induced pluripotent stem cell-derived microglia (iMG) to express G795A. Xenotransplantation studies demonstrate that G795A-iMG exhibit nearly identical gene expression to wildtype iMG, respond to inflammatory stimuli, and progressively expand in the presence of PLX3397, replacing endogenous microglia to fully occupy the brain. In sum, we engineered a human CSF1R variant that enables nontoxic, cell type, and tissue-specific replacement of microglia.

Figures
Products