CCR2 cooperativity promotes hematopoietic stem cell homing to the bone marrow

Sci Adv. 2024 Sep 20;10(38):eadq1476. doi: 10.1126/sciadv.adq1476. Epub 2024 Sep 18.

Abstract

Cross-talk between hematopoietic stem and progenitor cells (HSPCs) and bone marrow (BM) cells is critical for homing and sustained engraftment after transplantation. In particular, molecular and physical adaptation of sinusoidal endothelial cells (ECs) promote HSPC BM occupancy; however, signals that govern these events are not well understood. Extracellular vesicles (EVs) are mediators of cell-cell communication crucial in shaping tissue microenvironments. Here, we demonstrate that integrin α4β7 on murine HSPC EVs targets uptake into ECs. In BM ECs, HSPC EVs induce up-regulation of C-C motif chemokine receptor 2 (CCR2) ligands that synergize with CXCL12-CXCR4 signaling to promote BM homing. In nonirradiated murine models, marrow preconditioning with HSPC EVs or recombinant CCR2 ligands improves homing and early graft occupancy after transplantation. These findings identify a role for HSPC EVs in remodeling ECs, newly define CCR2-dependent graft homing, and inform novel translational conditioning strategies to improve HSPC transplantation.

MeSH terms

  • Animals
  • Bone Marrow Cells / cytology
  • Bone Marrow Cells / metabolism
  • Bone Marrow* / metabolism
  • Cell Movement
  • Chemokine CXCL12 / metabolism
  • Endothelial Cells / cytology
  • Endothelial Cells / metabolism
  • Extracellular Vesicles* / metabolism
  • Hematopoietic Stem Cell Transplantation
  • Hematopoietic Stem Cells* / cytology
  • Hematopoietic Stem Cells* / metabolism
  • Humans
  • Mice
  • Mice, Inbred C57BL
  • Receptors, CCR2* / metabolism
  • Receptors, CXCR4 / metabolism
  • Signal Transduction

Substances

  • Ccr2 protein, mouse
  • Chemokine CXCL12
  • Receptors, CCR2
  • Receptors, CXCR4
  • CCR2 protein, human