Leucocyte Separation Using Magnetotactic Bacteria

在新鲜和海洋沉积物中发现了趋磁细菌，它们可以定向并沿着地磁场游动。这些细菌含有由磁铁矿组成的磁性颗粒，其尺寸受控（50-100 nm）。最近，研究小组报告说，细菌磁性颗粒可以通过使用聚乙二醇的细胞融合引入红细胞。如果将磁性颗粒引入由淋巴细胞和吞噬细胞（粒细胞和单核细胞）组成的白细胞中，则可以通过施加磁场将它们引导到目标位置来用于治疗。本研究通过吞噬作用将趋磁细菌导入粒细胞和单核细胞。磁性控制含细菌磁性颗粒的吞噬细胞的运动，并通过施加磁场将吞噬细胞与淋巴细胞分离。磁敏感白细胞的应用（例如，引入动物）。含有细菌磁性颗粒的吞噬细胞（磁敏感细胞）的数量在孵育90分钟后变得恒定，并且活的吞噬细胞含有约20 - 40个趋磁细菌细胞。用钐钴磁铁将含有细菌磁性颗粒的粒细胞和单核细胞与淋巴细胞分离。分离后，回收了89%的淋巴细胞，95%的细胞存活。回收的淋巴细胞中吞噬细胞的污染低于0.8%。通过施加磁场去除磁敏感性粒细胞和单核细胞。趋磁细菌吞噬细胞对硝基四氮唑的还原能力、趋化能力和吞噬能力分别为84%、88%和87%。

Magnetotactic bacteria which orient and swim along a geomagnetic field have been found in fresh and marine sediments. These bacteria contain magnetic particles consisting of magnetite in a controlled size (50-100 nm). Recently, the investigator's group reported that bacterial magnetic particles can be introduced into red blood cells by cell fusion using polyethylene glycol. If magnetic particles are introduced into leucocytes consisting of lymphocytes and phagocytes (granulocytes and monocytes), they can be used for therapy by being guided to the objective position by applying a magnetic field. In this research, magnetotactic bacteria were introduced into granulocytes and monocytes by phagocytosis. The movement of phagocytes containing bacterial magnetic particles was magnetically controlled and phagocytes were separated from lymphocytes by applying magnetic field. Application of magneto-sensitive leucocytes (eg. introduction into animal) were also carried out. The number of phagocytes containing bacterial magnetic particles (magneto-sensitive cells) became constant after 90 min incubation, and viable phagocytes contained about 20 - 40 cells of magnetotactic bacteria. Granulocytes and monocytes containing bacterial magnetic particles were separated by a samarium-cobalt magnet from lymphocytes. After separation, 89% of lymphocytes were recovered and 95% of the cells were viable. The contamination of phagocytes in the recovered lymphocytes was below 0.8%. Magnetosensitive granulocytes and monocytes were removed by applying a magnetic field. The nitroblue tetrazolium reducing, chemotactic and phagocytic abilities of phagocytes ingesting magnetotactic bacteria were 84%, 88% and 87% respectively after 1 hr incubation.