van de Loosdrecht A A, Beelen R H, Ossenkoppele G J, Broekhoven M G, Langenhuijsen M M
Department of Hematology, University Hospital, Amsterdam, The Netherlands.
Exp Hematol. 1993 Mar;21(3):461-8.
Activated human monocytes and macrophages are involved in host defense against neoplastic cells. In view of cellular adoptive immunotherapy, we have studied the role of tumor necrosis factor-alpha (TNF-alpha) and gamma-interferon (IFN-gamma) in monocyte-mediated cytotoxicity on the level of both effector and leukemic target cells. Highly purified and IFN-gamma-activated monocytes were cytolytic to U937 cells up to 81.9 +/- 5.3% (mean +/- SEM) in a 24-hour MTT cytotoxicity assay at an effector-to-target-cell ratio of 10. Upon IFN-gamma activation these monocytes showed a 20-fold increase in TNF-alpha secretion of 663 +/- 122 pg/mL. Comparable concentrations of recombinant human TNF-alpha showed only cytostatic effects on U937 cells of approximately 20% after 24 hours, similar to the cytostatic effects of IFN-gamma-activated monocyte culture supernatants. These effects could be fully reversed by anti-TNF-alpha antibodies. U937 cells pretreated with TNF-alpha were almost completely resistant to monocyte-mediated cytotoxicity, supernatant-mediated cytostasis and to TNF-alpha up to 10(4) U/mL. IFN-gamma-activated monocytes were able to lyse TNF-alpha-modified U937 cells whereas IFN-gamma-activated monocyte supernatants showed only cytostatic activity after prolonged incubation. Additionally, target cell modulation by IFN-gamma potentiated the TNF-alpha-dependent cytolytic and cytostatic effects of monocytes, monocyte culture supernatants and TNF-alpha. We conclude that monocytes as a cellular component in monocyte-mediated cytotoxicity are far more potent in lysis of leukemic target cells than are secreted monokines. Furthermore, IFN-gamma and TNF-alpha are involved in the regulation of the susceptibility of leukemic cells for lysis by interactions with monocytes.
活化的人类单核细胞和巨噬细胞参与宿主对肿瘤细胞的防御。鉴于细胞过继性免疫疗法，我们已经在效应细胞和白血病靶细胞水平上研究了肿瘤坏死因子-α（TNF-α）和γ-干扰素（IFN-γ）在单核细胞介导的细胞毒性中的作用。在效应细胞与靶细胞比例为10的24小时MTT细胞毒性试验中，高度纯化且经IFN-γ激活的单核细胞对U937细胞的细胞毒性高达81.9±5.3%（平均值±标准误）。经IFN-γ激活后，这些单核细胞的TNF-α分泌增加了20倍，达到663±122 pg/mL。相当浓度的重组人TNF-α在24小时后对U937细胞仅显示约20%的细胞生长抑制作用，类似于IFN-γ激活的单核细胞培养上清液的细胞生长抑制作用。这些作用可被抗TNF-α抗体完全逆转。用TNF-α预处理的U937细胞对单核细胞介导的细胞毒性、上清液介导的细胞生长抑制以及高达10(4) U/mL的TNF-α几乎完全耐药。IFN-γ激活的单核细胞能够裂解经TNF-α修饰的U937细胞，而IFN-γ激活的单核细胞上清液在长时间孵育后仅显示细胞生长抑制活性。此外，IFN-γ对靶细胞的调节增强了单核细胞、单核细胞培养上清液和TNF-α的TNF-α依赖性细胞毒性和细胞生长抑制作用。我们得出结论，作为单核细胞介导的细胞毒性中的细胞成分，单核细胞在裂解白血病靶细胞方面比分泌的单核因子更有效。此外，IFN-γ和TNF-α通过与单核细胞相互作用参与调节白血病细胞对裂解的敏感性。
