Generation Of Enhanced Antitumor Activity Of Tumor Draining Lymph Node Cells After Induced With Autologous Dendritic Cells In Vitro

Tumor-draining lymph nodes (TDLN) are an excellent source of tumor-reactive T lymphocytes and the adoptive transfer of these cells is capable of mediating the regression of tumors established.In the present studies, TDLN cells were activated with anti-CD3 monoclonal antibody or tumor antigen followed by culture with recombinant interleukin-2 (rIL-2). These methods were not or less useful to signal transduction impairments of T cells. Establishment of an immune response against cancer may depend on the capacity of dendritic cells to transfer costimulatory molecules into T cells. To check this possibility, we used monocyte-derived dendritic cells (DC) loaded with tumor lysate inducing autologous TDLN cells.Tumor lysates loaded DC were prepared from peripheral blood mononuclear of the patients with gastric adenocarcinoma and incubated with combination of GM-CSF, IL-4, TNF- a ,and the tumor lysate from the patients for 7 days. TDLN cells were isolated and purified from regional lymph nodes of the patients and incubated with IL-2 for 7 days. Then we design experiment groups including (1) TDLN cells activated by DC, (2) TDLN cells activated by tumor lysate, (3) TDLN cells alone, which were used as control. Because TDLN cells in our experiment were isolated and purified from regional lymph nodes of gastric adenocarcinoma patients, we used KATO3, a gastric adenocarcinoma cell line, as target cells and A375, a human melanoma cell line as contral cells. After 3 days, phenotypes of three TDLN cells were studied by FCM. Then KAYO3 cells and A375 cells wereco-cultured with TDLN cells respectively at various ratios for 3 days. Cytotoxicity was assessed by MTT assay.The results showed that TDLN cells activated by DC mediated significantly greater cytotoxic activity of KATO3 cells than did TDLN cells activated by tumor lysate or TDLN cells alone. In contrast, for A375, cytotoxic activities of three TDLN cells were similar. These studies demonstrated that specific antitumor reactivity of TDLN cells could be enhanced significant after activated by autologous monocyte-derived dendritic cells loaded with tumor lysate.