Xie Z, Cao X, Zhang W
Institute of Biophysics, Second Military Medical University, Shanghai, 200433.
Zhonghua Yi Xue Za Zhi. 1999 Mar;79(3):166-9.
To compare the endocytic routes of exogenous antigen in murine dendritic cells (DC) and macrophages.
Murine bone marrow-derived DC and peritoneal macrophages were pulsed with HRP-5 nm colloidal gold for 10 minutes and chased for 0-120 minutes in culture medium. Intracellular distribution of 5 nm colloidal gold was explored by means of cellular enzymatic-chemistry of acidic phosphatase and MHC II cellular immunochemistry under electron microscope.
After 10 minutes pulse with HRP-5 nm colloidal gold and then 30 minutes of chase, most of HRP-5 nm colloidal gold internalized by DC entered into MHC II positive MIICs, but a little entered into acidic phosphatase-positive lysosomes. In contrast to DC, most of lysosomes of macrophages were accessed by HRP-5 nm colloidal gold, and a small portion of HRP-5 nm colloidal gold entered into MIICs. After 60 minutes of chase, 5 nm colloidal gold could hardly be seen within macrophages, whereas most of 5 nm colloidal gold retained in DC.
The endocytic route of exogenous antigen in DC apparently differs from that in macrophages. Most of antigens taken by macrophages enter into lysosomes within 30 minutes. In the case of DC, most of internalized antigens enter into MIICs, which may be related to their unique antigen-presenting function. In addition, macrophages seem to have more powerful capacity of scavenging exogenous antigen than DC.
比较外源性抗原在小鼠树突状细胞（DC）和巨噬细胞中的内吞途径。
用HRP - 5nm胶体金脉冲处理小鼠骨髓来源的DC和腹腔巨噬细胞10分钟，然后在培养基中追踪0 - 120分钟。通过电子显微镜下酸性磷酸酶的细胞酶化学和MHC II细胞免疫化学研究5nm胶体金的细胞内分布。
用HRP - 5nm胶体金脉冲处理10分钟后再追踪30分钟，DC内化的大部分HRP - 5nm胶体金进入MHC II阳性的MIICs，但少量进入酸性磷酸酶阳性的溶酶体。与DC相反，巨噬细胞的大多数溶酶体被HRP - 5nm胶体金占据，一小部分HRP - 5nm胶体金进入MIICs。追踪60分钟后，巨噬细胞内几乎看不到5nm胶体金，而DC中大部分5nm胶体金仍保留。
DC中外源性抗原的内吞途径明显不同于巨噬细胞。巨噬细胞摄取的大多数抗原在30分钟内进入溶酶体。就DC而言，大多数内化抗原进入MIICs，这可能与其独特的抗原呈递功能有关。此外，巨噬细胞对外源性抗原的清除能力似乎比DC更强。
