Conclusion
We conclude that there is no advantage in using the AkaBLI system to track the biodistribution of systemically administered cell-based regenerative medicine therapies in vivo.
Methods
Umbilical cord mesenchymal stromal cells (MSCs) were transduced to produce two genetically engineered populations, expressing either AkaLuc or the engineered FLuc luc2. The bioluminescence of AkaLuc+ and FLuc+ cells was assessed both in vitro (emission spectra, saturation kinetics and light emission per cell) and in vivo (substrate kinetics following intraperitoneal and subcutaneous administration and biodistribution of the cells up to day 7).
Purpose
To systematically compare the performance of AkaBLI and the standard Firefly luciferase (FLuc) systems to monitor the biodistribution and fate of cell therapies in rodents.
Results
Introduction of the reporter genes has no effect on MSC phenotype. For BLI, the FLuc system is superior to AkaBLI in terms of (i) light output, producing a stronger signal after subcutaneous substrate delivery and more consistent signal kinetics when delivered intraperitoneally; (ii) absence of hepatic background; and (iii) safety, where the AkaLuc substrate was associated with a reaction in the skin of the mice in vivo.