Anticancer therapy by hybrids of dendritic cells and interferon-α-overexpressing cells

基于树突状细胞（DC）的免疫疗法已被用于临床治疗癌症，尽管大多数尝试显示不足的反应。树突状细胞与肿瘤细胞的融合技术在实验模型和临床试验中得到了广泛的应用。为了克服肿瘤患者的免疫抑制状态，基于肿瘤的疫苗接种结合细胞因子基因治疗也被用于治疗这些肿瘤。我们之前在小鼠低免疫原性结直肠癌模型中显示了IFN-α-过表达肿瘤的有效性。因此，我们认为使用dc与过表达IFN-α-的肿瘤细胞杂交进行免疫治疗可能比使用dc与野生型细胞杂交治疗具有更强的抗肿瘤作用。在这项研究中，我们在小鼠模型中评估了dc和IFN-α基因转导的结直肠癌细胞杂交治疗的抗肿瘤作用。我们利用逆转录病毒载体建立了过表达IFN-α的MC38结直肠癌细胞株（MC38-IFNα，每10^6个细胞/48h产生157.0…More +-4.2 ng的IFN-α）。我们用聚乙二醇制备DCs和mc38 - ifn - α细胞的杂交体。为了评估其预防作用，在注射野生型MC38 （MC38- wt）前7天将这些杂交体注射到免疫功能正常的小鼠体内。作为一种针对已建立肿瘤的治疗方法，在注射MC38-WT细胞7天后，对侧接种杂交细胞。融合后的dc和mc38 -IFN -α细胞有17-25%的杂种细胞，这些细胞产生大量的IFN-α。预注射杂交体能有效地阻止野生型肿瘤在所有小鼠体内的植入。在针对已建立的肿瘤的治疗模型中，dc和MC38-IFNα细胞的杂交细胞比dc和MC38-WT细胞的杂交细胞更有效地抑制肿瘤的生长。免疫组织化学分析显示，dc和MC38-IFNα细胞杂交处理的小鼠肿瘤中有明显的CD8^+细胞浸润。利用dc与IFN-α-转导的肿瘤细胞杂交进行免疫治疗可有效诱导细胞抗肿瘤免疫应答，应在临床试验中予以考虑。少

Dendritic cell (DC)-based immunotherapy has been used clinically against cancer although most attempts showed insufficient responses. Fusion technique for DCs and tumor cells has been developed and widely used in experimental models as well as clinical trials. To overcome an immunosuppressed state in patients with tumors, tumor-based vaccination in combination with cytokine gene therapy has also been used in treatment of these tumors. We previously showed the efficacy of IFN-α-overexpressing tumor in a murine poorly immunogenic colorectal cancer model. Therefore, we thought that immunotherapy using hybrids of DCs and IFN-α-overexpressing tumor cells might have more antitumor effects compared with therapy with hybrids of DCs and wild-type cells. In this study, we evaluated antitumor effects of therapy with hybrids of DCs and IFN-α gene transduced colorectal cancer cells in a murine model. We established an IFN-α-overexpressing MC38 colorectal cancer cell line (MC38-IFNα, producing 157.0 … More +-4.2 ng of IFN-α/10^6cells/48h) using a retroviral vector. We made hybrids of DCs and MC38-IFNα cells with polyethyleneglycol. To evaluate the preventive effects, the hybrids were injected in immunocompetent mice 7 days before injection of wild-type MC38 (MC38-WT). As a therapy against established tumors, hybrids were inoculated contralaterally 7 days after MC38-WT cells had been injected. Hybrids were detected 17-25% of the fused DCs and MC38-IFNα cells, and these cells produced a large amount of IFN-α. Preinjection of hybrids prevented implantation of wild-type tumors effectively in all mice. In the therapeutic model against established tumors, hybrids of DCs and MC38-IFNα cells suppressed growth of the tumors more effectively than hybrids of DCs and MC38-WT cells. Immunohistochemical analysis showed marked infiltration of CD8^+ cells in the established tumors of mice treated with hybrids of DCs and MC38-IFNα cells. Immunotherapy using hybrids of DCs and IFN-α-transduced tumor cells induces cellular antitumor immune response effectively, and should be considered in clinical trials. Less