This invention discloses a method for preparing NK cells, the NK cells obtained thereby, and their applications. The method includes: sorting NK cells from
peripheral blood of an allogeneic donor; culturing them in a serum-
free medium containing CD3
monoclonal antibody, CD16
antibody, and IL-2, without the need for a
feeder layer; preferably, IL-21 is added for amplification on days 3-5 of culture, and the cells are cultured for 20-40 days. This method yields non-genetically modified NK cells, among which CD56... bright The NK cells comprise >90% of the
cell line and highly express a variety of activating and functional molecules. These NK cells effectively clear Aβ oligomers and senescent cells, and alleviate
neuroinflammation. In treatment, intracranial injection achieves equivalent or better
efficacy with only about 1 / 10th the
dose administered intravenously, significantly clearing Aβ deposits in the brains of AD model mice and improving
pathology.