血小板生成素转导鼠T淋巴细胞的增殖和分化

THROMBOPOIETIN cNDA TRANSFER PROMOTES T LYMPHOCYTE PROLIFERATION AND DIFFERENTIATION IN MICE

为探讨ＴＰＯ（血小板生成素）基因导入对Ｔ细胞增殖和分化影响的规律，将编码人ＴＰＯ的质粒ＤＮＡ６０μｇ用脂质体包裹后，经肌肉途径转导入Ｂａｌｂ／ｃ小鼠体内。用ＣＤ４和ＣＤ８的特异性抗体标记小鼠各种免疫组织中的Ｔ细胞，借助流式细胞术分析它们的组成和变化。结果发现ＴＰＯ基因导入使骨髓中的成熟和未成熟Ｔ细胞数量在经过短期下降后全部大幅度增多，胸腺未成熟Ｔ细胞增加；而脾脏和血液循环中成熟Ｔ细胞增多，特别是在血液中ＣＤ４阳性细胞的增加最为明显。这些特点大约在基因导入后两周内形成，并持续至少两周以上。本文所得的结果提示ＴＰＯ是一种免疫促进分子，ＴＰＯ基因导入后小鼠血液中多种淋巴因子的升高与它过量表达对Ｔ细胞的刺激有关。

To elucidate the effect of thrombopoietin(TPO) on the differentiation and proliferation of T lymphocytes via gene transferance,60μg human TPO plasmid DNA encapsulated with lipofectin (10μg/μl) was delivered into Balb/c mice.Monoclonal antibodies against murine CD4 or CD8 molecules were employed to directly stain the mononuclear cells from the immune tissues and were analyzed by flow cytometry.Mice treated with null plasmid or saline were used as controls.Results showed that with the delivery of TPO cDNA,both mature and immature T lymphocytes in bone marrow increased in frequencies after a transient declination.Immature T lymphocytes in thymus increased while mature T lymphocytes increased mainly in spleens and blood circulation.Among them CD4 + T subsets selectively proliferated in the process.These changes appeared around 2 weeks after gene transfer and remained for at least 2 weeks.The data suggest that TPO might be an immuno regulator and the cytokine over production in gene transferved mice might be due to the activation of T lymphocytes,especially the helper subgroups.