Studies on differentiation inducing factors for human myelogenous leukemic cells and enhancement of their activity.

人髓系白血病细胞可被称为分化诱导因子(DIF)的各种化学物质和蛋白质诱导剂诱导分化为单核/巨噬细胞。然而，人的DIF还没有得到很好的描述。在本项目中，我们试图从PHA刺激的淋巴细胞和成纤维细胞条件培养的EADA中纯化DIF，并成功地从淋巴细胞条件培养液中纯化出一种均一的DIF。纯化的DIF相对分子质量约为17,000，NH_2末端序列与人肿瘤坏死因子(TNF)相同。我们还成功地从人成纤维细胞系(WI-26VA4)的条件培养液中纯化出成纤维细胞来源的分化诱导因子(F-DIF)。经SDS-PAGE分析，纯化的DIF的相对分子质量约为27,000，HN_2末端序列与人白细胞介素6(IL-6)的HN-末端序列相同，但没有N-末端的脯氨酸。当与肿瘤坏死因子联合使用时，F-DIF协同诱导人髓系白血病细胞系分化。肿瘤坏死因子和白介素6与其他生物反应调节剂如前列腺素E_2、维甲酸、维生素D_3、干扰素等协同促进分化。本研究结果表明，肿瘤坏死因子和白介素6具有另一种新的生物学效应。这可能是控制感染过程中细胞反应的调控信号之一。联合应用细胞因子和BRM可能在影响临床白血病的终末分化中发挥作用。

Human myelogenous leukemic cells can be induced to differentiate into the monocyte/macrophage pathway by various chemicals and protein inducers called differentiation inducing factors(DIF). However, human DIF has not yet been well characterized. We have tried to purified DIFs from eadia conditioned by PHA-stimulated lymphocytes and fibroblasts in this project.We have succeeded to purify a DIF homogeneity from lymphocyte conditioned medium. The purified DIF has a relative molecular mass of approximately 17,000, with an NH_2-terminal sequence the same as that of human tumor necrosis factor(TNF). We have also succeeded to purigy a fibroblast-derived differentiation inducing factor(F-DIF) from medium conditioned by a human fibroblast cell line(WI-26VA4). The purified DIF had a molecular weight of about 27,000 determined by SDS-PAGE, with an HN_2-terminal sequence the same as that of human interleukin-6(IL-6) except for the absence of the N-terminal proline. F-DIF synergistically induced differentiation of human myelogenous leukemic cell lines when combined with TNF.F-DIF synergistically enhanced the differentiation of human myelogenous leukemic cell lines when combined with TNF. TNF and IL-6 synergistically enhanced the differentiation in combination with other biological response modifiers such as prostaglendin E_2, retinoic acid, vitamid D_3, interferon- , etc.The results presented in this project point to another new biological effects of TNF and IL-6. This could be one of the regulatory signals that control cellular reactions during infection. Combination use of cytokines and BRM may play in effecting terminal differentiation of the clinical leukemias.