IFN-γ在小鼠造血调节中的作用

Role of IFN-γ in the Regulation of Murine Hemopoiesis

本研究旨在探讨IFN-γ在小鼠骨髓造血调节中的作用及其作用机制。通过RT-PCR方法扩增小鼠IFN-γ(mIFN-γ)片段,构建mIFN-γ慢病毒表达载体pCDH1-mIFN-γ-EF1-copGFP(pCDH-mIFN-γ-GFP)。将pCDHmIFN-γ-GFP和pCDH1-EF1-copGFP(pCDH-GFP)分别与辅助质粒pPACK-A、pPACK-B、pPACK-C组合,通过磷酸钙沉淀法转染293T细胞,制备慢病毒。通过慢病毒将mIFN-γ和GFP转导至C57BL/6J雄性小鼠的骨髓单个核细胞,接种于M3434甲基纤维素完全培养基进行集落形成试验,同时将其通过尾静脉注射给致死剂量照射的受体C57BL/6J小鼠体内,定期进行血常规检查。结果显示,成功构建pCDH-mIFN-γ-GFP慢病毒载体;转导mIFN-γ的293T细胞分泌mIFN-γ蛋白;转导mIFN-γ的小鼠骨髓单个核细胞集落生成数量较对照组显著减少,集落形成能力下降;mIFN-γ组的骨髓移植小鼠血象恢复较GFP对照组延迟,移植后8周流式细胞术检测外周血仍可见GFP阳性细胞。结论:mIFN-γ降低了造血干/祖细胞的增殖能力,延缓骨髓移植小鼠的造血恢复时间。

This study was aimed to explore the role and mechanism of IFN-γ in the regulation of hemopoiesis in mice. Murine IFN-γfragment was amplified from murine splenic cells with RT-PCR and plasmid pCDHI-mIFN-γ-EF1-copGFP （pCDH-mIFN-γ-GFP） was constructed. Plasmids pCDH-mIFN-γ-GFP and pCDHI-EFI-copGFP （pCDH- GFP） together with packaging plasmids pPACK-A, pPACK-B and pPACK-C were respectively transfected into 293T cells by using a method of calcium phosphate precipitation to produce lentivirus. Bone marrow mononuclear cells （BMMNC） from male C57BL/6J mice were transfected with the lentiviral vector pCDH expressing mIFN-γand green fluorescent protein （GFP）. The cells were cultured in M3434 semi-solid medium for colony formation assay and transplanted into lethally-irradiated mice through caudal vein injection, and the peripheral blood cell counts and GFP were monitored regularly after transplantation. The results showed that lentiviral vector pCDH-mIFN-γ-GFP was constructed successfully and 293T cells transfected with mIFN-γsecreted mIFN-γ. Transfection of mIFN-γinto BMMNC decreased colony formation, colony number of the mIFN-γ group was significantly less than that of the control group. The recovering of circulating blood cell parameters in mIFN-γtransplantation group was significantly later than control group. GFP positive cells could be detected in the peripheral blood at 8 weeks after transplantation. It is concluded that mIFN-γ may inhibit the colony-fonning capacity of transduced BMMNC and delay the hematopoiefic reconstitution.