Itoh K, Tilden A B, Balch C M
J Immunol. 1986 May 15;136(10):3910-5.
The ability of NK cells to lyse noncultured solid tumor cells was investigated, and the results were compared with lysis of K562. Purified NK cell fractions separated by either Percoll centrifugation or a cell sorter exhibited higher level of lysis against noncultured melanoma cells than did NK-depleted cell fractions. However, the level of lysis was low (less than 10% lysis). Adding recombinant interleukin 2 (rIL 2) to the 4-hr assay induced significant lysis (more than 10%) of noncultured melanoma cells in 18 of 23 (78%) Percoll-enriched NK cell fractions and seven of 11 (64%) sorted Leu-11a+ cells at an E:T ratio of 80 and 10, respectively. In contrast, only two of 13 (14%) PBMC, five of 17 (29%) Percoll-decreased NK cell fractions, and one of 12 (8%) sorted Leu-11a- cells lysed noncultured melanomas in the presence of rIL 2. rIL 2 induced NK cells to lyse noncultured lung and breast cancer cells, as well as melanoma tumors. Exposure of NK cells to 2000 rad radiation abrogated the rIL 2-induced cytotoxicity against noncultured melanomas. Preculture of PBMC for 18 hr with recombinant interferon-gamma (rIFN-gamma) resulted in a modest level of lysis of non-cultured melanomas by sorted Leu-11a+ cells. Adding rIL 2 to the assay increased the cytotoxic activity in both rIFN-gamma-activated Leu-11a+ and Leu-7+ NK subsets. The level of noncultured tumor lysis correlated well with that of K562 lysis in all of the experiments. Purified NK cell fractions in rIL 2 cultures increased cytotoxic activity against noncultured tumor cells with incubation time for up to 3 days, and the level of NK cell-mediated lysis was dependent on both doses of rIL 2 and length of incubation. In contrast, both NK-depleted and sorted Leu-11a- cells demonstrated very low levels of solid tumor lysis after 3-day cultures with a high dose of rIL 2. Killer cell precursors induced by 3-day cultures of sorted cell fractions with rIL 2 and rIFN-gamma were found in both Leu-11a+ and Leu-7+ NK subsets, but not Leu-4+ or Leu-3a+ T lymphocytes. These results indicate that NK cells become cytotoxic for noncultured solid tumor cells by a brief contact with rIL 2, and increase cytotoxic activity after culture with rIL 2.
研究了自然杀伤（NK）细胞裂解未培养的实体瘤细胞的能力，并将结果与对K562细胞的裂解情况进行了比较。通过Percoll离心或细胞分选仪分离得到的纯化NK细胞组分，对未培养的黑色素瘤细胞的裂解水平高于NK细胞耗竭的细胞组分。然而，裂解水平较低（低于10%）。在4小时的检测中加入重组白细胞介素2（rIL-2），在E:T比例分别为80和10时，23个Percoll富集的NK细胞组分中有18个（78%）、11个分选的Leu-11a+细胞中有7个（64%）对未培养的黑色素瘤细胞产生了显著裂解（超过10%）。相比之下，在rIL-2存在的情况下，13个外周血单核细胞（PBMC）中只有2个（14%）、17个Percoll降低的NK细胞组分中有5个（29%）、12个分选的Leu-11a-细胞中有1个（8%）能裂解未培养的黑色素瘤细胞。rIL-2可诱导NK细胞裂解未培养的肺癌、乳腺癌细胞以及黑色素瘤肿瘤。将NK细胞暴露于2000拉德辐射可消除rIL-2诱导的对未培养黑色素瘤细胞的细胞毒性。用重组干扰素-γ（rIFN-γ）将PBMC预培养18小时后，分选的Leu-11a+细胞对未培养的黑色素瘤细胞有适度的裂解水平。在检测中加入rIL-2可增加rIFN-γ激活的Leu-11a+和Leu-7+NK亚群的细胞毒性活性。在所有实验中，未培养肿瘤的裂解水平与对K562细胞的裂解水平密切相关。在rIL-2培养物中，纯化的NK细胞组分对未培养肿瘤细胞的细胞毒性活性随孵育时间延长至3天而增加，且NK细胞介导的裂解水平取决于rIL-2的剂量和孵育时间。相比之下，用高剂量rIL-2培养3天后，NK细胞耗竭的细胞和分选的Leu-11a-细胞对实体瘤的裂解水平都非常低。在分选的细胞组分用rIL-2和rIFN-γ培养3天诱导产生的杀伤细胞前体，在Leu-11a+和Leu-7+NK亚群中都有发现，但在Leu-4+或Leu-3a+T淋巴细胞中未发现。这些结果表明，NK细胞通过与rIL-2短暂接触而对未培养的实体瘤细胞产生细胞毒性，并在与rIL-2培养后增加细胞毒性活性。
