抗MBL单抗1C8对人单核-巨噬细胞调理吞噬功能的影响及其机制

Effects and mechanisms of anti-MBL mAb 1C8on opsonophagocytosis of monocyte/macrophages in vitro

甘露聚糖结合凝集素(MBL)通过激活补体凝集素途径而发挥间接调理作用。本研究探讨了抗人MBL单抗1C8对凝集素途径介导人单核-巨噬细胞调理功能的影响及其机制。采用流式细胞术和荧光显微镜观察,发现1C8能抑制人单核细胞和巨噬细胞对白色念珠菌的吞噬;通过凝集试验观察到,1C8能阻断重组人MBL糖识别域蛋白(rhMBL-CRD)介导的白色念珠菌、大肠杆菌凝集;ELISA和western blot分析结果显示,1C8特异性地与rhMBL-CRD结合,这种结合可被甘露聚糖、D-甘露糖胺和D-葡糖胺等阻断。结果表明,1C8通过结合糖识别域,竞争性抑制MBL与微生物表面糖结构的结合,进而阻断补体凝集素途径的活化,从而发挥对单核巨噬细胞调理吞噬的抑制作用。

The effects of anti mannan binding lectin （MBL） mAb 1C8 on the opsonophagocytosis of monocytes/macrophages in vitro and its mechanisms were studied, h was found that mAb 1C8 could significantly inhibit opsonophagocytosis of Candida albicans by monocytes and macrophages, as demonstrated by fluorescence microscopy and flow cytometry analysis, and aggluti nation assay showed that agglutination of Candida albicans and Esckerichia coil mediated by recombinant human MBL-carbo hydrate recognition domain （rhMBL CRD） was inhibited . The specific binding of mAb 1C8 to rhMBL CRD was concentrationdependent, which could be blocked by mannan, mannose, D-galactose, D-galactosamine, D-mannosamine and D glucosamine, as shown by Western blot and ELISA. These results suggest that 1C8 inhibits MBL-mediated activation of complement through competing against MBL-CRD for binding to carbohydrate ligands on the surface of microbes, resulting in inhibition of op sonophagocyosis by macrophages/monocytes.