In vivo cell kinetics of the bone marrow transplantation using dual colored transgenic rat system

Abstract

Because bone marrow is an adequate site for bone marrow stem cells, intra-bone marrow - bone marrow transplantation (IBM-BMT) is an efficient strategy for bone marrow transplantation (BMT). However, the fate of the transplanted cells remains unclear. Herein, we established a dual-colored transgenic rat system utilizing green fluorescent protein (GFP) and a luciferase (luc) marker. We then utilized this system to investigate the in vivo kinetics of transplanted bone marrow cells (BMCs) after authentic intravenous (IV)-BMT or IBM-BMT. The in vivo fate of the transplanted cells was tracked using an in vivo luminescent imaging technique; alterations in peripheral blood chimerism were also followed using flow cytometry. IBM-BMT and IV-BMT were performed using syngeneic and allogeneic rat combinations. While no difference in the proliferation pattern was observed between the two treatment groups at 7 days after BMT, different distribution patterns were clearly observed during the early phase. In the IBM-BMT-treated rats, the transplanted BMCs were engrafted immediately at the site of the injected bone marrow and expanded more rapidly than in the IV-BMT-treated rats during this phase. Graft-versus-host disease was also visualized. Our bio-imaging system using dual-colored transgenic rats is a powerful tool for performing quantitative and morphological assessments in vivo.