CCL3 and CCL20-recruited dendritic cells modified by melanoma antigen gene-1 induce anti-tumor immunity against gastric cancer ex vivo and in vivo.
BACKGROUND
To investigate whether dendritic cell (DC) precursors, recruited by injection of chemokine ligand 3 (CCL3) and CCL20, induce anti-tumor immunity against gastric cancer induced by a DC vaccine expressing melanoma antigen gene-1 (MAGE-1) ex vivo and in vivo.


METHODS
B6 mice were injected with CCL3 and CCL20 via the tail vein. Freshly isolated F4/80-B220-CD11c+ cells cultured with cytokines were analyzed by phenotype analysis and mixed lymphocyte reaction (MLR). For adenoviral (Ad)-mediated gene transduction, cultured F4/80-B220-CD11c+ cells were incubated with Ad-MAGE-1. Vaccination of stimulated DC induced T lymphocytes. The killing effect of these T cells against gastric carcinoma cells was assayed by MTT. INF-gamma production was determined with an INF-gamma ELISA kit. In the solid tumor and metastases model, DC-based vaccines were used for immunization after challenge with MFC cells. Tumor size, survival of mice, and number of pulmonary metastatic foci were used to assess the therapeutic effect of DC vaccines.


RESULTS
F4/80-B220-CD11c+ cell numbers increased after CCL3 and CCL20 injection. Freshly isolated F4/80-B220-CD11c+ cells cultured with cytokines were phenotyically identical to typical DC and gained the capacity to stimulate allogeneic T cells. These DCs were transduced with Ad-MAGE-1, which were prepared for DC vaccines expressing tumor antigen. T lymphocytes stimulated by DCs transduced with Ad-MAGE-1 exhibited specific killing effects on gastric carcinoma cells and produced high levels of INF-gamma ex vivo. In vivo, tumor sizes of the experimental group were much smaller than both the positive control group and the negative control groups (P < 0.05). Kaplan-Meier survival curves showed that survival of the experimental group mice was significantly longer than the control groups (P < 0.05). In addition, MAGE-1-transduced DCs were also a therapeutic benefit on an established metastatic tumor, resulting in a tremendous decrease in the number of pulmonary metastatic foci.


CONCLUSIONS
CCL3 and CCL20-recruited DCs modified by adenovirus-trasnsduced, tumor-associated antigen, MAGE-1, can stimulate anti-tumor immunity specific to gastric cancer ex vivo and in vivo. This system may prove to be an efficient strategy for anti-tumor immunotherapy.
He
Songbing
S
Department of General Surgery, the First Affiliated Hospital of Soochow University, 215006 Suzhou, Jiangsu Province, China.
Wang
Liang
L
Wu
Yugang
Y
Li
Dechun
D
Zhang
Yanyun
Y
D000818:Animals; D000951:Antigens, Neoplasm / Q000096:biosynthesis*; D019496:Cancer Vaccines / Q000627:therapeutic use*; D002277:Carcinoma / Q000473:pathology; D054418:Chemokine CCL20 / Q000096:biosynthesis*; D054405:Chemokine CCL3 / Q000096:biosynthesis*; D003713:Dendritic Cells / Q000378:metabolism*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008168:Lung / Q000473:pathology*; D058950:Melanoma-Specific Antigens; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D013274:Stomach Neoplasms / Q000473:pathology; D013601:T-Lymphocytes / Q000378:metabolism
D000951:Antigens, Neoplasm; C108355:CCL20 protein, human; C515429:CCL3 protein, human; D019496:Cancer Vaccines; D054418:Chemokine CCL20; D054405:Chemokine CCL3; C072011:MAGEA1 protein, human; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins