淋巴细胞趋化因子基因修饰增强肿瘤抗原多肽致敏的树突状细胞的 …

目的 通过选择性增强树突状细胞（ＤＣ）与Ｔ细胞的体内相互作用。优化其体内抗原提呈的微环境,为进一步增强ＤＣ介导的肿瘤免疫治疗效果。方法 体外培养的小鼠骨髓树突太细胞体外经Ｌｔｎ重组腺病毒感染后（Ｌｔｎ－ＤＣ）,用３ＬＬＬｅｉｗｓ肺癌细胞株的Ｍｕｔｌ抗原肽冲击致敏,按不同剂量免疫正常同系小鼠体内,观察其体内诱导的细胞毒性Ｔ淋巴细胞（ＣＴＬ）活性保护性免疫反应。通过体内阻断试验探讨免疫细胞亚群及免疫分

Enhanced antitumor effects induced by lymphotactin gene-modified dendritic cells after pulsed with tumor antigen peptide

OBJECTIVE: To evaluate the potent effects of lymphotactin on tumor immunogene therapy and to improve the therapeutic efficacy of dendritic cells (DCs)-based vaccine, the protective and therapeutic effects of tumor antigen peptide-pulsed lymphotactin gene-modified dendritic cells were investigated. METHODS: In the tumor model of 3LL Lewis lung carcinoma, mouse bone marrow DCs transduced with mouse lymphotactin gene by adenovirus vector (Ltn-DC) were pulsed with MHC-I-restricted, 3LL cell-specific tumor peptide Mut 1 (FEQNTAQP), and used to vaccinate syngeneic mice or to treat the preestablished tumor-bearing mice with spontaneous pulmonary metastases. RESULTS: Immunization with Mut 1 peptide-pulsed Ltn-DC induced specific CTL against 3LL cells and induced protective antitumor immunity, which rendered the immunized mice resistant completely to 3LL tumor challenge. In vivo depletion of immune cell subsets with mAbs demonstrated that the protective immunity induced by Mut1 peptide-pulsed Ltn-DC in the induction phase was dependent on both CD4+ T cells and CD8+ T cells rather than NK cells, and in the effector phase on CD8+ T cells rather than CD4+ T cells or NK cells. CD28/CTLA4 pathway of T cell costimulation and IFN-gamma were also necessary for induction of antitumor immunity by Ltn-DC pulsed with Mut1 peptide. Treatment with Mut1 peptide-pulsed Ltn-DC significantly inhibited the 3LL spontaneous pulmonary metastases of the preestablished tumor-bearing mice and exhibited obvious therapeutic effects. CONCLUSIONS: Our data suggest that Ltn gene modified DCs are more potent in the induction of protective and therapeutic antitumor immunity through the preferential chemotaxis of DCs on T cells. Vaccination with tumor antigen-pulsed Ltn-DC may be a novel approach to immunotherapy of cancer.