目的：研究可溶性DC-SIGN（sDC-SIGN）对未成熟树突状细胞（imDC）吞噬金黄色葡萄球菌（金葡菌）的影响及机制。方法采用流式细胞术分析sDC-SIGN对imDC吞噬金葡菌的影响；ELISA检测sDC-SIGN分别与金葡菌、脂磷壁酸、脂多糖的结合；观察配体甘露聚糖、脂磷壁酸以及抗人DC-SIGN抗体1C6和4H3对sDC-SIGN与金葡菌结合的影响。结果 sDC-SIGN能抑制imDC对金葡菌的吞噬。sDC-SIGN与金葡菌结合，且呈Ca2+依赖性；以浓度依赖方式与脂磷壁酸结合，但不与脂多糖结合；sDC-SIGN与金葡菌的结合可被甘露聚糖、金葡菌磷壁酸和1C6、4H3阻断。结论 sDC-SIGN通过优先与金葡菌表面的一些糖成分结合而影响imDC膜表面DC-SIGN与金葡菌的结合，从而抑制了imDC对金葡菌的吞噬。%Objective To study the effect and mechanism of soluble dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (sDC-SIGN) on the phagocytosis of Staphylococcus aureus (S. aureus) by immature dendritic cells (imDCs). Methods Flow cytometry was employed to examine the effect of sDC-SIGN on the phagocytosis of S. aureus by imDCs. Enzyme-linked immunosorbent assay (ELISA) was used to analyze the binging of sDC-SIGN to S. aureus, lipoteichoic acid (LTA) and lipopolysaccharides (LPS) and investigate the effect of the ligands mannan and LTA and anti-DC-SIGN antibodies 1C6 and 4H3 on the binging of sDC-SIGN to S. aureus. Results sDC-SIGN inhibited the phagocytosis of S. aureus by imDCs. sDC-SIGN bound to S. aureus in a Ca2+-dependent manner. sDC-SIGN concentration-dependently bound to LTA, but not to LTA, and the binging of sDC-SIGN to S. aureus was blocked by mannan, LTA, 1C6 and 4H3. Conclusion sDC-SIGN preferentially binds to the carbohydrate constituents on S. aureus to affect the binding between membrane-bound DC-SIGN and S. aureus, thus suppressing the phagocytosis of S. aureus by imDCs.
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