体内不同生长期腹水瘤细胞对NK结合、杀伤的敏感性

NK细胞能在体内外杀伤各种瘤细胞,但并非所有的肿瘤对NK的杀伤都敏感。许多肿瘤.特别是由体内原发肿瘤部位及转移灶中分离的瘤细胞对NK的结合及杀伤表现出不同程度的抗性。不同的瘤细胞对NK杀伤敏感性上的差异与这些细胞表面“NK靶细

In Vivo Suceptibilities of Ascitic Sarcoma 180(S180)Cells to Natural killer (Nk)C8ll-Mediated Binding and Killing During Their Development

The suceptibilities of ascitic S180 cells to NK cell-mediated binding and killing during their development in vivo were studied at a single cell level, usingsingle cell cytotoxic and binding assaies. The results showed that the NK binding and killing suceptibilities of ascitic S180 cells changed sequentialy during their growth in vivo, the kinetics of which had an appearence of reversed S with both NK binding and killingsuceptibilities being the highest at the fifth day and the lowest at the second day and the tenth day after inoculation of the tumors. However, the changes were seen to be similar when the tumors were inoculated in either adult(6-7-week-old) or yaung(3-week-old) mice, or in different strains of adult mice. Analysis at a single cell level revealed that the change in the NK suceptibilitg of the tumor cells at different growth stages were concomitant with the changes in the number of the tumor target cells capable of being bound by NK cells as shown with an NK-target binding assay, which was consistant to the flactuation of the capability on which the tumor target cells could bind more than one NK cell. Our results indicate the NK-suceptibility of ascitic S180 cells changes uring their growth in vivo, due to the changes of the ratio of NK-suceptible and-nonsuceptible target cells in the tumor cells at different growth stages. The possible cause(s) for the changes is discussed here.