Reporter gene-expressing bone marrow-derived stromal cells are immune-tolerated following implantation in the central nervous system of syngeneic immunocompetent mice.
BACKGROUND
Cell transplantation is likely to become an important therapeutic tool for the treatment of various traumatic and ischemic injuries to the central nervous system (CNS). However, in many pre-clinical cell therapy studies, reporter gene-assisted imaging of cellular implants in the CNS and potential reporter gene and/or cell-based immunogenicity, still remain challenging research topics.


RESULTS
In this study, we performed cell implantation experiments in the CNS of immunocompetent mice using autologous (syngeneic) luciferase-expressing bone marrow-derived stromal cells (BMSC-Luc) cultured from ROSA26-L-S-L-Luciferase transgenic mice, and BMSC-Luc genetically modified using a lentivirus encoding the enhanced green fluorescence protein (eGFP) and the puromycin resistance gene (Pac) (BMSC-Luc/eGFP/Pac). Both reporter gene-modified BMSC populations displayed high engraftment capacity in the CNS of immunocompetent mice, despite potential immunogenicity of introduced reporter proteins, as demonstrated by real-time bioluminescence imaging (BLI) and histological analysis at different time-points post-implantation. In contrast, both BMSC-Luc and BMSC-Luc/eGFP/Pac did not survive upon intramuscular cell implantation, as demonstrated by real-time BLI at different time-points post-implantation. In addition, ELISPOT analysis demonstrated the induction of IFN-gamma-producing CD8+ T-cells upon intramuscular cell implantation, but not upon intracerebral cell implantation, indicating that BMSC-Luc and BMSC-Luc/eGFP/Pac are immune-tolerated in the CNS. However, in our experimental transplantation model, results also indicated that reporter gene-specific immune-reactive T-cell responses were not the main contributors to the immunological rejection of BMSC-Luc or BMSC-Luc/eGFP/Pac upon intramuscular cell implantation.


CONCLUSIONS
We here demonstrate that reporter gene-modified BMSC derived from ROSA26-L-S-L-Luciferase transgenic mice are immune-tolerated upon implantation in the CNS of syngeneic immunocompetent mice, providing a research model for studying survival and localisation of autologous BMSC implants in the CNS by real-time BLI and/or histological analysis in the absence of immunosuppressive therapy.
Bergwerf
Irene
I
Laboratory of Experimental Hematology, University of Antwerp, Antwerp, Belgium. irene.bergwerf@ua.ac.be
De Vocht
Nathalie
N
Tambuyzer
Bart
B
Verschueren
Jacob
J
Reekmans
Kristien
K
Daans
Jasmijn
J
Ibrahimi
Abdelilah
A
Van Tendeloo
Viggo
V
Chatterjee
Shyama
S
Goossens
Herman
H
Jorens
Philippe G
PG
Baekelandt
Veerle
V
Ysebaert
Dirk
D
Van Marck
Eric
E
Berneman
Zwi N
ZN
Linden
Annemie Van Der
AV
Ponsaerts
Peter
P
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology*; D001921:Brain / Q000378:metabolism; D002478:Cells, Cultured; D003952:Diagnostic Imaging; D017930:Genes, Reporter; D008156:Luciferases / Q000235:genetics* / Q000378:metabolism; D049408:Luminescent Agents / Q000378:metabolism; D008163:Luminescent Measurements; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D023421:Models, Animal; D017154:Stromal Cells / Q000637:transplantation*; D023001:Transplantation Tolerance
D049408:Luminescent Agents; D008156:Luciferases