The Preconditioning of Busulfan Promotes Efficiency of Human CD133+ Cells Engraftment in NOD Shi-SCID IL2Rγcnull (NOG) Mice via Intra-Bone Marrow Injection

Abstract

Human CD133⁺ stem cells were injected into the bone marrow cavity of NOG (NOD Shi-SCID IL2Rγc^null) mice with or without preconditioning of busulfan in order to assess the efficiency of human CD133⁺ cells engraftment. Peripheral blood from CD133⁺-engrafted NOG mice was analyzed by flow cytometry. The results showed that human CD19⁺ B lymphocytes could be detected at 4 weeks post-transplantation, and human CD4⁺, CD8⁺ subsets of T lymphocytes, CD19^- CD14^- HLA-DR⁺ DCs and CD19^- CD14⁺ monocytes could be detected at 16 weeks post-transplantation. The survival rate of mice in busulfan-untreated group (100%) was slightly higher than that in the busulfan-pretreated group (83%) (P > 0.05). However, the differentiation efficiency of CD133⁺ stem cells in busulfan-pretreated group was significantly higher than that in the untreated group (P < 0.05). This data imply that CD133⁺ cells could be a good resource for a humanized mouse model, and the preconditioning of busulfan could be more conducive to accelerating the differentiation of human CD133⁺ cells in NOG mice by intra-bone marrow injection.

Keywords: CD133 stem cells; busulfan; hematopoietic differentiation; humanized mouse model.

Fig 1.

Generation and assessment of humanized mice. (A) Operation of intra-bone marrow injection. (B) Assessment of percent survival of humanized mice. Six humanized mice in each group were monitored weekly. (C) Differentiation of human CD45+ and CD19+ cells in each groups at 4 weeks post-transplantation (wpt). D. the significant difference between control and busulfan groups in the ratio of hCD45 to mCD45 and percentage of human lymphocytes subsets at 4 wpt. **P < 0.01, Data are mean ± SEMs in humanized mice (n = 6, each group).

Fig 2.

Human lymphocytes, DCs and monocytes detection in peripheral blood of CD133⁺-transplanted NOG mice at 16 wpt. (A) the differentiation of human CD4⁺, CD8⁺ and CD19⁺ cells in each groups. (B) Significant difference between control and busulfan groups in the ratio of hCD45 to mCD45 and percentage of human lymphocytes subsets. *P < 0.05, **P < 0.01, Data are mean ± SEMs in humanized mice (n = 6, each group). (C) Differentiation of human CD14^–HLA-DR⁺, CD14⁺CD16^– and CD14⁺CD16⁺ cells in each group. (D) Significant difference between control and busulfan groups in percentage of human DCs and monocytes. *P < 0.05. Data are mean ± SEMs in humanized mice (n = 6, each group).