Gene and Cell Therapy Center, Hematology Department-BMT Unit, George Papanicolaou Hospital, Thessaloniki 57010, Greece.
Hum Gene Ther. 2010 Mar;21(3):299-310. doi: 10.1089/hum.2009.077.
Granulocyte colony-stimulating factor (G-CSF)-mobilized blood stem cells may become the preferable source of hematopoietic stem cells (HSCs) for gene therapy because of the higher yield of cells compared with conventional bone marrow harvesting. A G-CSF-associated risk of splenic rupture has been recognized in normal donors of HSCs, but limited information is available about the G-CSF effect in the presence of splenomegaly and extramedullary hematopoiesis. We investigated the G-CSF effect in a thalassemic mouse model (HBB(th-3)) as compared with a normal strain (C57BL/6), in terms of safety, mobilization efficacy, and distribution of stem cells among hematopoietic compartments. There was no death or clinical sequelae of splenic rupture in G-CSF-treated animals of either strain; however, hemorrhagic infarcts in the spleen were detected with low frequency in G-CSF-treated HBB(th-3) mice (12.5%). HBB(th-3) mice mobilized less effectively than C57BL/6 mice (Lin(-)Sca-1(+)c-Kit(+) cells/microl of peripheral blood mononuclear cells [PBMCs]: 90 +/- 55 vs. 255 +/- 174, respectively, p = 0.01; CFU-GM/ml PBMCs: 390 +/- 262 vs. 1131 +/- 875, p = 0.01) because of increased splenic trapping of hematopoietic stem and progenitor cells (Lin(-)Sca-1(+)c-Kit(+) cells per spleen (x10(5)): 487 +/- 35 vs. 109 +/- 19.6, p = 0.01; CFU-GM per spleen (x10(2)): 1470 +/- 347 vs. 530 +/- 425, p = 0.0006). Splenectomy restored the mobilization proficiency of thalassemic mice at comparable levels to normal mice and resulted in the development of a hematopoietic compensatory mechanism in the thalassemic liver that protected splenectomized mice from severe anemia. Our data imply that, in view of human gene therapy for thalassemia, either multiple cycles or alternative ways of mobilization may be required for a sufficient yield of transplantable HSCs. In addition, strategies to minimize the risk of G-CSF-induced splenic infarcts should be explored in a clinical setting.
粒细胞集落刺激因子 (G-CSF) 动员的血液干细胞可能成为基因治疗中造血干细胞 (HSCs) 的首选来源，因为与传统的骨髓采集相比，其细胞产量更高。在 HSCs 的正常供体中，已经认识到 G-CSF 与脾脏破裂的相关性风险，但关于 G-CSF 在脾肿大和骨髓外造血存在时的作用，信息有限。我们在地中海贫血小鼠模型 (HBB(th-3)) 中与正常品系 (C57BL/6) 进行了比较，研究了 G-CSF 的安全性、动员效果以及干细胞在造血隔室中的分布。两种品系的 G-CSF 治疗动物均未死亡或出现脾脏破裂的临床后遗症；然而，在 G-CSF 治疗的 HBB(th-3)小鼠中，脾脏中检测到低频率的出血性梗死 (12.5%)。HBB(th-3) 小鼠的动员效果不如 C57BL/6 小鼠（外周血单个核细胞中的 Lin(-)Sca-1(+)c-Kit(+)细胞/微升 [PBMCs]：分别为 90 +/- 55 和 255 +/- 174，p = 0.01；CFU-GM/ml PBMCs：分别为 390 +/- 262 和 1131 +/- 875，p = 0.01），因为造血干细胞和祖细胞的脾脏捕获增加（Lin(-)Sca-1(+)c-Kit(+)细胞/脾脏 (x10(5))：分别为 487 +/- 35 和 109 +/- 19.6，p = 0.01；CFU-GM/脾脏 (x10(2))：分别为 1470 +/- 347 和 530 +/- 425，p = 0.0006）。脾切除术使地中海贫血小鼠的动员效率恢复到与正常小鼠相当的水平，并在贫血小鼠的肝脏中产生了一种造血代偿机制，使脾切除术的贫血小鼠免受严重贫血的影响。我们的数据表明，鉴于人类地中海贫血的基因治疗，可能需要多个循环或替代动员方式来获得足够数量的可移植 HSCs。此外，应该在临床环境中探索降低 G-CSF 诱导的脾脏梗死风险的策略。
