Schnurr Max, Scholz Christoph, Rothenfusser Simon, Galambos Peter, Dauer Marc, Röbe Julian, Endres Stefan, Eigler Andreas
Department of Medicine, Divisions of Clinical Pharmacology and Gastroenterology, Ludwig-Maximilians-University of Munich, 80336 Munich, Germany.
Cancer Res. 2002 Apr 15;62(8):2347-52.
Tumor vaccines using dendritic cells (DCs) have been shown to induce antitumor CTL responses. The choice of the tumor antigen preparation used for DC loading is still an unresolved issue. We compared DCs pulsed with cell lysates, whole apoptotic tumor cells or their supernatants of the HLA-A2(+) human pancreatic carcinoma cell line Panc-1 for their capacity to activate T cells. Monocyte-derived DCs from HLA-A2(+) donors were pulsed with tumor antigen, matured subsequently, and cocultured with autologeous peripheral blood mononuclear cells. After three weekly restimulations with DCs, T-cell activation was assessed by intracellular IFN-gamma staining and cytotoxicity assays. Compared with lysate, pulsing DCs with the supernatant of apoptotic tumor cells induced a higher frequency of activated CTLs and T-helper cells, as well as an enhanced MHC class I-restricted tumor cell lysis. No activation of natural killer (NK) or gammadelta T cells was detected. Pulsing DCs with whole apoptotic tumor cells induced an even more pronounced lytic effect. However, in this case, MHC class-I blocking was only partially effective, and unrelated cell lines were also killed. IFN-gamma staining revealed activation of CTLs and T-helper cells, as well as NK and gammadelta T cells. Trans-well cultures of NK cells, apoptotic tumor cells, and DCs showed that NK cell activation was dependent on direct cell-to-cell contact with tumor cells and the presence of interleukin-12 produced by DCs. These results indicate that the choice of antigen preparation is a critical determinant in the induction of antitumor immunity. Tumor vaccines consisting of DCs and apoptotic tumor cells may be able to activate CTLs, as well as effector cells of the innate immune system.
使用树突状细胞（DCs）的肿瘤疫苗已被证明可诱导抗肿瘤CTL反应。用于DC负载的肿瘤抗原制剂的选择仍然是一个未解决的问题。我们比较了用HLA-A2(+)人胰腺癌细胞系Panc-1的细胞裂解物、完整凋亡肿瘤细胞或其上清液脉冲处理的DCs激活T细胞的能力。来自HLA-A2(+)供体的单核细胞衍生DCs用肿瘤抗原脉冲处理，随后成熟，并与自体外周血单核细胞共培养。在用DCs进行三周的每周一次再刺激后，通过细胞内IFN-γ染色和细胞毒性试验评估T细胞活化。与裂解物相比，用凋亡肿瘤细胞的上清液脉冲处理DCs可诱导更高频率的活化CTL和T辅助细胞，以及增强的MHC I类限制性肿瘤细胞裂解。未检测到自然杀伤（NK）或γδ T细胞的活化。用完整凋亡肿瘤细胞脉冲处理DCs可诱导更明显的裂解作用。然而，在这种情况下，MHC I类阻断仅部分有效，并且无关细胞系也被杀死。IFN-γ染色显示CTL和T辅助细胞以及NK和γδ T细胞的活化。NK细胞、凋亡肿瘤细胞和DCs的Trans-well培养表明，NK细胞活化依赖于与肿瘤细胞的直接细胞间接触以及DCs产生的白细胞介素-12的存在。这些结果表明，抗原制剂的选择是诱导抗肿瘤免疫的关键决定因素。由DCs和凋亡肿瘤细胞组成的肿瘤疫苗可能能够激活CTL以及先天免疫系统的效应细胞。
