Fig. 4.

Intra-hepatically transplanted hNIS-mGFP⁺ HLCs behave similarly compared to untransduced HLCs | hNIS-mGFP⁺ and control, non-reporter expressing HLCs from the same batch of differentiation were transplanted intrahepatically at day 23 of differentiation. (A) Scheme of the in vivo experiment indicating control or hNIS-mGFP⁺ HLC intrahepatic transplant and ^99mTcO₄⁻-afforded NIS imaging sessions by SPECT/CT two days or six days post-transplant. (B/C) SPECT/CT sagittal (left) and transverse (right) slices of transplanted mice imaged two days after transplantation. Expected endogenous signals (from stomach) are visible in both groups of animals. Importantly, hNIS-mGFP⁺ HLCs were detected at the expected location in the liver in corresponding animals two days after transplantation (B/green arrows and circle). However, six days post transplantation, no hNIS-mGFP⁺ HLC were detectable (C). In control animals no signals were recorded at any time, as expected (B/C). (D) Standard uptake values (SUV) from relevant tissues determined from in vivo images using VivoQuant (Invicro) software. (E) Representative post-mortem liver lobes from animals two days after transplantation (matching (B)). Areas containing transplanted cells (pale red, brightfield) are visible. Fluorescence excitation (450/20 nm BP) paired with a camera behind an emission filter (500 nm LP) allowed specific visualization of hNIS-mGFP⁺ HLCs, while untransduced control HLCs were not detectable, confirming cell survival and functionality of the hNIS-mGFP⁺ reporter at two days after transplantation. (F) 10 µm liver sections of snap-frozen livers from corresponding livers in B and D were stained for human albumin, indicating presence of human cells alongside mouse liver cells (no human albumin staining, different morphology in brightfield). (G) Mouse serum from animals sacrificed two days after HLC transplantation was subjected to ELISA analysis for human albumin. Even at this early time point after transplantation, ELISA allowed the detection of human serum in both reporter-expressing and untransduced animals, confirming the function of the transplanted cell at this time point. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)