Division of Oncology/Blood and Marrow Transplantation, The Children's Hospital of Philadelphia and The University of Pennsylvania School of Medicine, Philadelphia, Pa., USA.
Exp Hematol. 2010 Sep;38(9):836-44. doi: 10.1016/j.exphem.2010.04.015. Epub 2010 May 4.
Transplantable osteoprogenitors, as well as hematopoietic progenitors, reside in bone marrow. We previously reported the first clinical trial of bone marrow transplantation (BMT) for a genetic disorder of bone, osteogenesis imperfecta. Although the patients demonstrated striking clinical benefits after transplantation, measured osteopoietic engraftment was low and did not seem to be durable. Therefore, we sought an animal model, which closely reflects the clinical experience, to facilitate development of strategies to improve the efficiency of osteoprogenitor engraftment after BMT.
We transplanted unfractionated bone marrow cells from green fluorescent protein-transgenic mice into lethally irradiated recipients in four combinations of inbred mouse strains: from C57BL/6 into C57BL/6 (C-C), from C57BL/6 into FVB/N (C-F), from FVB/N into C57BL/6 (F-C), and from FVB/N into FVB/N (F-F). At 2 weeks after transplantation, we assessed donor hematopoietic and osteopoietic engraftment by flow cytometry, using a novel mean fluorescence assay, and by immunohistochemical staining for green fluorescent protein.
Hematopoietic reconstitution by donor cells was complete in all four combinations. Although osteopoietic engraftment of the transplanted cells was also documented in all the four groups, the magnitude of osteopoietic engraftment differed markedly among the strains where F-F > C-F > F-C > C-C.
Our findings indicate that the genetic background of inbred mouse strains affects efficiency of osteopoietic engraftment after BMT. Thus, the murine strain must be considered when comparing experimental outcomes. Moreover, comparing the genetic variation among murine strains may lend insight into the factors governing osteopoietic differentiation of transplanted marrow cells.
造血祖细胞和骨髓中的可移植成骨细胞都存在于骨髓中。我们之前报道了首例骨髓移植（BMT）治疗骨遗传病成骨不全症的临床试验。尽管患者在移植后表现出明显的临床益处，但测量的成骨植入率较低，且似乎不持久。因此，我们寻求一种动物模型，该模型可紧密反映临床经验，以促进开发提高 BMT 后成骨细胞植入效率的策略。
我们将绿色荧光蛋白转基因小鼠的未分离骨髓细胞移植到四种近交系小鼠的致死性照射受者中：C57BL/6 到 C57BL/6（C-C）、C57BL/6 到 FVB/N（C-F）、FVB/N 到 C57BL/6（F-C）和 FVB/N 到 FVB/N（F-F）。移植后 2 周，我们通过流式细胞术，使用新型平均荧光测定法，以及通过免疫组织化学染色法检测绿色荧光蛋白，评估供体造血和成骨细胞植入情况。
所有四种组合的供体细胞均完全重建了造血功能。尽管在所有四组中均证明了移植细胞的成骨植入，但不同品系之间的成骨植入量差异显著，其中 F-F > C-F > F-C > C-C。
我们的研究结果表明，近交系小鼠的遗传背景会影响 BMT 后的成骨植入效率。因此，在比较实验结果时，必须考虑到鼠种。此外，比较不同鼠种的遗传差异可能有助于了解调控移植骨髓细胞成骨分化的因素。
