A Functional Bioluminescent Zebrafish Screen for Enhancing Hematopoietic Cell Homing

Summary

To discover small molecules that modulate hematopoietic cell homing after adoptive transfer, we created a transgenic zebrafish expressing firefly luciferase downstream of the ubiquitin promoter ( ubi:luc) to serve as a hematopoietic donor. Bioluminescence imaging (BLI) was used to detect and follow ubi:luc hematopoietic cells that homed to the marrow as early as 1 day post-transplant. BLI was able to detect the biological effect of prostaglandin E ₂ on early homing/engraftment of donor hematopoietic cells. This system was utilized in a functional screen of small molecules to enhance homing/engraftment. We discovered a phytosterol, ergosterol, that could increase hematopoietic cell homing in zebrafish and mice. In addition, ergosterol increased CXCR4 expression and promoted expansion of Lin ⁻SCA-1 ⁺KIT ⁺ cells in vitro. We have demonstrated the utility of in vivo BLI to non-invasively monitor donor hematopoietic cell activity in adult zebrafish as a functional screen for mediators of cellular homing.

Highlights

• •

  Bioluminescent imaging (BLI) can track engrafting hematopoietic cells

• •

  BLI can be used for screening of enhancers of hematopoietic cell homing

• •

  Using BLI, ergosterol was found to increase hematopoietic cell homing

• •

  Ergosterol affects hematopoietic progenitor migration, growth, and viability in vitro

Abstract

Accelerating cell homing after adoptive transfer may expediate recovery after hematopoietic transplant. Lund and colleagues developed a novel zebrafish model utilizing bioluminescent imaging to track hematopoietic cell homing, thus allowing for a functional screening approach of small molecule libraries.