中文摘要：

目的研究小鼠骨髓细胞来源的树突状细胞对细菌颗粒抗原交叉递呈的动力学特点。方法取小鼠骨髓细胞，采用GM—CSF诱导培养。用倒置显微镜观察培养过程中细胞形态，用流式细胞仪进行细胞纯度和表型测定。采用第7天未成熟的DC细胞进行细菌抗原的交叉递呈能力检测和动力学分析。结果小鼠骨髓细胞经GM—CSF诱导培养，第7天获得大量具有典型形态和免疫表型的树突状细胞，并且在细菌脂多糖刺激后，其表型也发生特征性变化表现在共刺激分子CD80由刺激前的27．7％上调到71．6％，CD86从刺激前的36．0％上调到80．3％，DEC205从刺激前的6．5％上调到26．2％。同时该细胞吞噬低剂量的细菌抗原即可有效活化T细胞，其动力学曲线为：1～3h，该细胞抗原递呈能力呈对数增加，3～8h DC抗原递呈能力进入一个平台期，10～12h，抗原递呈能力又迅速增强。结论采用GM—CSF可以从小鼠骨髓中获得大量纯度高并且具有典型免疫表型的DC，该DC细胞能有效的递呈外源性细菌抗原，并具有特殊的抗原递呈动力学曲线。

英文摘要：

Objective To investigate the kinetic characteristics of the cross presentation of bacterial antigen by bone marrow-derived dendritic cells. Methods Dendritic cells （DCs） were induced by GM-CSF from mouse bone marrow in vitro. Then the morphological features of the DCs were observed by invert optical microscope and the phenotypes changes were evaluated by flow cytometry. Bacteria antigen cross presentation assay was performed by DCs after 7 days of culture. Results Large numbers of DCs could be obtained from mouse bone marrow by GM-CSF induction. The DCs had the typical morphology and phenotypes changes after stimulating by lipopolysaccharide, and had the ability to activate T cells after phagocytosis bacteria antigens at low does. Antigen cross presentation ability increased remarkable at 1 - 3 h after culture, reached a platform at 3 - 8 h, and continued to improve sharply after 10 h culture. Conclusion DCs derived from bone marrow have typical phenotypes and specially kinetics of bacterial antigen processing for cross presentation.