低剂量辐射预处理后小鼠同基因移植模型中的供体嵌合现象与干细胞功能：逆转录病毒介导的基因转移方案的影响及其对基因治疗的意义

Donor chimerism and stem cell function in a murine congenic transplantation model after low-dose radiation conditioning: effects of a retroviral-mediated gene transfer protocol and implications for gene therapy.

作者信息

Goebel W Scott, Yoder Mervin C, Pech Nancy K, Dinauer Mary C

机构信息

Herman B. Wells Center for Pediatric Research and Department of Pediatrics, Hematology/Oncology, James Whitcomb Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, IN, USA.

出版信息

Exp Hematol. 2002 Nov;30(11):1324-32. doi: 10.1016/s0301-472x(02)00927-x.

DOI:10.1016/s0301-472x(02)00927-x

PMID:12423686

Abstract

OBJECTIVE

We investigated low-dose radiation conditioning for the transplantation of retrovirus-transduced cells in a C57Bl6/J murine model.

MATERIALS AND METHODS

The effect of low-dose radiation on stem cell function was investigated using a competitive repopulation assay. Stem cell function of marrow cells that underwent a retroviral-mediated gene transfer (RMGT) protocol was examined by this assay, and donor chimerism of these cells when transplanted into 160-cGy conditioned syngeneic hosts was compared to fresh marrow.

RESULTS

Irradiation with 300 or 160 cGy substantially decreased stem cell function as measured by competitive repopulation. Animals conditioned with 160 cGy and transplanted with 20 x 10(6) fresh marrow cells permitted donor cell engraftment of 53.6% +/- 11.4% 6 months after transplant compared to 100% donor cell engraftment after 1100 cGy irradiation. Lymphoid and myeloid engraftment did not significantly differ from total engraftment in submyeloablated hosts. When transplanted into lethally irradiated hosts, the competitive repopulating activity of marrow treated with a single dose of 5-fluorouracil followed by ex vivo culture according to a standard RMGT protocol was equal to 5-fluorouracil-only treated marrow. However, cells treated with 5-fluorouracil or 5-fluorouracil plus ex vivo culture for RMGT repopulated less well than fresh marrow cells in 160 cGy conditioned hosts.

CONCLUSIONS

Low-dose irradiation decreases host stem cell function, allowing engraftment of both fresh and RMGT protocol-treated marrow, although the engraftment of 5-fluorouracil-treated cells was reduced at least two-fold, and 5-fluorouracil plus RMGT protocol-treated cells at least three-fold, compared to fresh marrow. Modification of current RMGT protocols may be important for optimizing engraftment under these conditions.

摘要

目的

我们在C57Bl6/J小鼠模型中研究了低剂量辐射预处理用于逆转录病毒转导细胞移植的情况。

材料与方法

使用竞争性重建造模法研究低剂量辐射对干细胞功能的影响。通过该方法检测经过逆转录病毒介导基因转移（RMGT）方案处理的骨髓细胞的干细胞功能，并将这些细胞移植到接受160 cGy预处理的同基因宿主中时的供体嵌合率与新鲜骨髓进行比较。

结果

通过竞争性重建造模法检测，300 cGy或160 cGy的辐射显著降低了干细胞功能。接受160 cGy预处理并移植20×10⁶个新鲜骨髓细胞的动物，移植后6个月供体细胞植入率为53.6%±11.4%，而接受1100 cGy辐射后供体细胞植入率为100%。在亚骨髓清除的宿主中，淋巴细胞和髓细胞植入率与总植入率无显著差异。当移植到致死剂量辐射的宿主中时，按照标准RMGT方案先用单剂量5-氟尿嘧啶处理然后进行体外培养的骨髓的竞争性重建造模活性与仅用5-氟尿嘧啶处理的骨髓相同。然而，在接受160 cGy预处理的宿主中，用5-氟尿嘧啶或5-氟尿嘧啶加体外培养进行RMGT处理的细胞的植入情况不如新鲜骨髓细胞。