Wendel-Hansen V, Sällström J, De Campos-Lima P O, Kjellström G, Sandlund A, Siegbahn A, Carlsson M, Nilsson K, Rosén A
Mora General Hospital, Sweden.
Leukemia. 1994 Mar;8(3):476-84.
B-type of chronic lymphocytic leukemia (B-CLL) cells are inert to the potent transforming action of Epstein-Barr virus (EBV). The mitogenic action of Staphylococcus aureus Cowan I (SAC), MP6-thioredoxin, and interleukin 2 (IL-2), agents previously shown to induce proliferation in normal as well as in B-CLL cells, lifted this block, and EBV-positive cell lines could be established. It was not possible to establish cell lines of leukemic origin from cultures that were incubated with EBV alone or cytokine mix alone. CLL-cells infected with EBV only, expressed the viral nuclear antigen complex (EBNA), but not the viral latent membrane protein (LMP). They were not activated as measured by cell size and 3H-thymidine incorporation. In contrast, cells incubated with EBV and cytokine mix expressed both EBNA and LMP in parallel with enlargement and increased 3H-thymidine incorporation. These results emphasize that LMP expression is a prerequisite for growth transformation and immortalization and that cytokine activation signals are required for its expression in B-CLLs. Cells incubated with SAC/MP6-thioredoxin/IL-2 did not express any of the viral antigens, but were activated with regard to the mentioned parameters. Nine cell lines were established from six patients. From each of the three patients, we obtained 'twin'-pair lines: one corresponding to the malignant cell and the other to a normal B-lymphoblastoid cell. Thus, malignant and normal B-cell counterparts, from the very same donor, are at hand for comparative studies. The cell lines have been carried out for more than 12 months in culture. We conclude that B-CLL that are refractory to EBV-transformation can be rendered susceptible through in vitro cytokine activation.
B 型慢性淋巴细胞白血病（B-CLL）细胞对爱泼斯坦-巴尔病毒（EBV）的强大转化作用具有惰性。金黄色葡萄球菌 Cowan I（SAC）、MP6-硫氧还蛋白和白细胞介素 2（IL-2）等促有丝分裂剂，此前已证明能诱导正常以及 B-CLL 细胞增殖，解除了这种阻滞作用，从而可以建立 EBV 阳性细胞系。仅用 EBV 或仅用细胞因子混合物培养，都无法从白血病来源的培养物中建立细胞系。仅感染 EBV 的 CLL 细胞表达病毒核抗原复合物（EBNA），但不表达病毒潜伏膜蛋白（LMP）。通过细胞大小和 3H-胸苷掺入量测定，它们未被激活。相比之下，用 EBV 和细胞因子混合物培养的细胞同时表达 EBNA 和 LMP，同时细胞增大且 3H-胸苷掺入量增加。这些结果强调，LMP 表达是生长转化和永生化的前提条件，且细胞因子激活信号是其在 B-CLL 细胞中表达所必需的。用 SAC/MP6-硫氧还蛋白/IL-2 培养的细胞不表达任何病毒抗原，但在上述参数方面被激活。从 6 名患者中建立了 9 个细胞系。从三名患者中的每一位，我们都获得了“孪生”细胞系：一个对应恶性细胞，另一个对应正常 B 淋巴母细胞。因此，来自同一供体的恶性和正常 B 细胞对应物可用于比较研究。这些细胞系已在培养中传代超过 12 个月。我们得出结论，对 EBV 转化具有抗性的 B-CLL 可通过体外细胞因子激活而变得易感。
