CNS Repopulation by Hematopoietic-Derived Microglia-Like Cells Corrects Progranulin deficiency

  • Res Sq. 2023 Sep 12:rs.3.rs-3263412. doi: 10.21203/rs.3.rs-3263412/v1.
Pasqualina Colella  1 ,  Ruhi Sayana  1 ,  Maria Valentina Suarez-Nieto  1 ,  Jolanda Sarno  2 ,  Kwamina Nyame  3  4 ,  Jian Xiong  3  4 ,  Luisa Natalia Pimentel Vera  1 ,  Jessica Arozqueta Basurto  1 ,  Marco Corbo  5 ,  Anay Limaye  5 ,  Kara Lynn Davis  2 ,  Monther Abu-Remaileh  3  4  6 ,  Natalia Gomez-Ospina  1
Affiliations
  • 1. Department of Pediatrics, Stanford University School of Medicine, Stanford, CA, 94305.
  • 2. Hematology, Oncology, Stem Cell Transplant, and Regenerative Medicine, Department of Pediatrics, Stanford University, Stanford, CA, 94305.
  • 3. Department of Chemical Engineering, Stanford University, Stanford, CA 94305.
  • 4. Department of Genetics, Stanford University, Stanford, CA 94305.
  • 5. MedGenome, Inc, 348 Hatch Dr, Foster City, CA 94404.
  • 6. The Institute for Chemistry, Engineering and Medicine for Human Health (Sarafan ChEM-H), Stanford University, Stanford, USA.
PMID: 37790525 DOI: 10.21203/rs.3.rs-3263412/v1
Abstract

Hematopoietic stem cell transplantation can deliver therapeutic proteins to the CNS through donor-derived hematopoietic cells that become microglia-like cells. However, using standard conditioning approaches, hematopoietic stem cell transplantation is currently limited by low and slow engraftment of microglia-like cells. We report an efficient conditioning regimen based on Busulfan and a six-day course of microglia depletion using the colony-stimulating factor receptor 1 inhibitor PLX3397. Combining Busulfan-myeloablation and transient microglia depletion results in robust, rapid, and persistent microglia replacement by bone marrow-derived microglia-like cells throughout the CNS. Adding PLX3397 does not affect neurobehavior or has adverse effects on hematopoietic reconstitution. Through single-cell RNA Sequencing and high-dimensional CyTOF mass cytometry, we show that microglia-like cells are a heterogeneous population and describe six distinct subpopulations. Though most bone-marrow-derived microglia-like cells can be classified as homeostatic microglia, their gene signature is a hybrid of homeostatic/embryonic microglia and border associated-macrophages. Busulfan-myeloablation and transient microglia depletion induce specific cytokines in the brain, ultimately combining myeloid proliferative and chemo-attractive signals that act locally to repopulate microglia from outside the niche. Importantly, this conditioning approach demonstrates therapeutic efficacy in a mouse model of GRN deficiency. Transplanting wild-type bone marrow into Grn-/- mice conditioned with Busulfan plus PLX3397 results in high engraftment of microglia-like cells in the brain and retina, restoring GRN levels and normalizing lipid metabolism.

Products