【摘要】 本工作观察了小鼠淋巴结树突状细胞（ＤＣ）的光、电镜免疫组织化学特性，并探讨其功能。从ＦＩＴＩＣ致敏小鼠淋巴结分离的ＤＣ在体外可刺激ＦＩＴＣ特异性Ｔ－细胞株增殖。注射经ＵＶ照射、ＦＩＴＣ致敏的小鼠淋巴结细胞（ＤＬＮＣ）至受体小鼠，可导致该小鼠的免疫耐受；这些细胞在体外仍可促进ＦＩＴＣ特异性Ｔ－细胞株增殖，但明显弱于非ＵＶ照射小鼠ＤＬＮＣ的作用。免疫光镜下显示ＵＶ－ＦＩＴＣ致敏小鼠淋巴结的ＦＩＴＣ阳性ＤＣ与非ＵＶ照射ＦＩＴＣ致敏组一样也表达了ＭＡＣ－１、２、３和Ｆ４／８０等巨噬细胞标志，唯其ＦＩＴＣ阳性细胞率明显高于非照射ＦＩＴＣ致敏组动物。免疫电镜下显示这些细胞呈Ｉａ阳性和ＦＩＴＣ阳性，ＦＩＴＣ主要定位于线粒体和溶酶体结构等处。研究表明这些与ＦＩＴＣ致敏小鼠ＤＬＮＣ有关的细胞活性的差异与Ｉａ阳性ＤＣ数量减少、表面Ｉａ的表达、ＦＩＴＣ在ＤＣ内的分布变化无关。某些Ｉａ阳性ＤＣ胞质内可见Ｂｉｒｂｅｃｋ颗粒样结构，提示Ｉａ阳性ＤＣ的不同群体可迁移至ＵＶ照射小鼠的淋巴结。更多还原

【Abstract】 In this paper, we investigated immunohistochemical properties and function of lymphnode dendritic cells (DC) involved in FITC contact sensitization of UV-irradiated and unirradiated mice by light and electron microscopy. DC isolate 18hrs earlier from the draininglymph nodes (DLN) of unirradiated mice sensitized with FITC, which induced contact hypersensitivity upon injection into the footpads of naive mice, promoted the proliferation ofFITC-specific T-cell lines in vitro. Draining lymph node cells (DLNC) from mice exposed toUV irradiation and then sensitized with FITC to shaved skin, which induce tolerance uponinjection into recipient mice, and less proliferation of FITC-specific T-cell lines than DLNCfrom FITC-sensitized mice. The differences in activity of these cells, related to DLNC fromFITC-sensitized mice, did not attribute to a decreased number of la positive DC in DLN, decreased surface expression of la molecules on these cells, or an alteration in the intracellularlocalization of FITC. However, a significantly higher percentage of the FITC positive DCfrom UV-irradiated mice expressed Mao-1, Mao-2, Mao-3 and F4/80 macrophage markersthana did those from FITC sensitized mice. Fewer Ia-positive DCs contained Birbeck granules, suggesting that a different population of la positive DC may reach the DLN of UV-irradiated mice.更多还原