目的： 利用基因工程技术制备SDF-1与hGM-CSF的融合蛋白（SDF-1γ/rhGM-CSF），研究该融合蛋白对肿瘤患者造血和免疫功能的增强作用。 方法： 构建表达SDF-1γ/rhGM-CSF融合蛋白的pPIC9k-SDF1-rhGM-CSF1质粒，转染酵母菌，诱导SDF-1γ/rhGM-CSF融合蛋白的表达，Western blotting鉴定SDF-1γ/rhGM-CSF融合蛋白的表达。集落形成实验观察SDF-1γ/rhGM-CSF对骨髓细胞集落形成的影响，趋化实验检测其对未成熟树突状细胞（dendritic cell，DC）的趋化作用。 结果： 成功构建pPIC9k-SDF1-rhGM-CSF1质粒，高表达SDF-1γ/rhGM-CSF融合蛋白，分子量约为25 000，并可被GM-CSF特异性抗体所识别。SDF-1γ/rhGM-CSF融合蛋白能显著刺激骨髓细胞的集落形成，其效果强于GM-CSF（P<0.05）。与SDF-1相比，SDF-1γ/rhGM-CSF融合蛋白可更有效地趋化未成熟DC（P<0.05）。 结论： SDF-1γ/rhGM-CSF融合蛋白可有效促进骨髓细胞的集落形成，趋化未成熟DC，有促进肿瘤化疗患者造血和免疫功能恢复的潜在临床应用前景。

Objective : To prepare the fusion protein of SDF-1 and rhGM-CSF (SDF-1γ/rhGM-CSF) by genetic engineering technology, and investigate its hematopoietic and immune promotion functions in tumor patients. Methods: The expression vector for SDF-1γ/rhGM-CSF fusion protein, pPIC9k-SDF1-rhGM-CSF1, was constructed and the protein expression was induced by yeast transfection. SDF-1γ/rhGM-CSF fusion protein was further identified by Western blotting analysis. Colony-formation assay and chemoattract assay were used to study the roles of the prepared fusion protein in stimulating bone marrow cell colony-formation and in chemoattracting immature dendritic cells. Results: SDF-1γ/rhGM-CSF fusion gene vector, pPIC9k-SDF1-rhGM-CSF1, was successfully constructed and expressed high level of SDF-1γ/rhGM-CSF fusion gene. The molecular weight of the expressed protein was about 25 000 and was recognized by GM-CSF specific antibody. The fusion protein had a stronger effect in stimulating bone marrow cell colony-formation than GM-CSF (P<005) and in chemoattracting immature dendritic cells than SDF-1 (P<0.05). Conclusion: SDF-1γ/rhGM-CSF fusion protein can promote bone marrow cell colony-formation and chemoattraction of immature dendritic cells, which might be used for promoting hematopoiesis and immune function of tumor patients after chemotherapy.

上海市自然科学基金资助项目（No.06ZR14114），军队医学研究"十一五"计划课题资助项目（No.10MA004）