Immunization with dendritic cells (DCs) pulsed with tumor antigen can activate tumor-specific cytotoxic T lymphocytes (CTL), which is responsible for tumor protection and regression. In this study, we examined whether DCs pulsed with necrotic tumor lysates can efficiently prevent malignant melanoma tumor cell metastasis to the lung. DCs derived from mouse bone marrow were found to produce remarkably elevated levels of IL-12 after being pulsed with the tumor lysates. Moreover, immunization with these DCs induced CTL activation and protected mice from metastasis development by intravenously inoculated tumor cells. In addition, these DCs activated NK cells in vitro in a contact-dependent manner, and induced NK activities in vivo. Furthermore, NK cell depletion before DC vaccination significantly reduced the tumor-specific CTL activity, IFN-g production, and IFN-gamma- inducible gene expression, and eventually interfered with the antitumor effect of tumor-pulsed DCs. Finally, similar findings with respect to NK cell dependency were obtained in the C57BL/ 6J-bg/bg mice, which have severe deficiency in cytolytic activity of NK cells. These data suggest that the antitumor effect elicited by DC vaccination, at least in a B16 melanoma model, requires the participation of both cytolytic NK and CD8+ T cells. The findings of this study would provide important data for the effective design of DC vaccines for cancer immunotherapy.
Animals ; Antigen Presentation/immunology ; CD8-Positive T-Lymphocytes/immunology ; Cancer Vaccines/*therapeutic use ; Cell Line, Tumor ; Cytokines/biosynthesis/immunology ; Dendritic Cells/immunology/*transplantation ; Female ; Interferon Type II/biosynthesis/immunology ; Interleukin-12/biosynthesis/immunology ; Killer Cells, Natural/*immunology ; Lung Neoplasms/immunology/prevention & control/secondary ; Lymphocyte Activation/immunology ; Lymphocyte Depletion ; Melanoma, Experimental/immunology/secondary/*therapy ; Mice ; Mice, Inbred C57BL ; Monocyte Chemoattractant Proteins/biosynthesis/immunology ; Research Support, Non-U.S. Gov't ; T-Lymphocytes, Cytotoxic/immunology

Animals ; Coculture Techniques ; Colonic Neoplasms ; pathology ; therapy ; Cytokines ; pharmacology ; Cytotoxicity, Immunologic ; Dendritic Cells ; immunology ; Female ; Immunophenotyping ; Immunotherapy, Adoptive ; Interferon-gamma ; biosynthesis ; Interleukin-12 ; biosynthesis ; Killer Cells, Natural ; immunology ; Lung Neoplasms ; prevention & control ; secondary ; Lymphocyte Activation ; Mice ; Mice, Inbred BALB C

Transduction of cytokine gene into tumor cells is a promising method of tumor therapy, but the value is limited by accompanying side effects. To focus antitumor immune response to tumor antigen-specific CTL, we developed an antitumor vaccine by transfecting modified IL-2 gene in a membrane-bound form (mbIL-2) into B16F10 melanoma cells. The mbIL-2 clone showed reduced tumorigenicity and metastatic ability, and inhibited metastasis and prolonged the survival of mice against B16F10 cells. The inhibition of B16F10 metastasis by mbIL-2 was accompanied by the increment of CD8+ T cells. The metastasis of mbIL-2 clone was significantly increased in the CD8+ T cell-depleted mice, but not in CD4+ T cell depleted mice. Spleen cells immunized with the mbIL-2 clone showed higher CTL activity towards B16F10 cells than those immunized with control cells. The size of CD8+ T cell population in the lung of mice injected with the mbIL-2 clone was markedly greater than that of mice injected with B16F10 cells, but there was no detectible change in CD4+ and CD8+ T cell populations of lymph nodes and spleen. These results suggest that when the mbIL-2 clone is introduced into the blood stream, it migrates mainly to lung and activates CD8+ T cells in situ, possibly by direct priming. Such a tumor vaccine may ameliorate the toxic side effects encountered with conventional cytokine gene therapy.
Animals ; CD4-Positive T-Lymphocytes ; CD8-Positive T-Lymphocytes/immunology ; Cancer Vaccines/*immunology ; Female ; *Genetic Engineering ; Interleukin-2/*genetics/metabolism ; Lung Neoplasms/*immunology/secondary/therapy ; Lymphocyte Activation ; Melanoma, Experimental/genetics/*immunology/*prevention & control ; Mice ; Mice, Inbred C57BL ; Research Support, Non-U.S. Gov't ; Spleen/immunology ; Survival Rate ; T-Lymphocytes, Cytotoxic/immunology ; Vaccination

Metastasis is the main cause of death in cancer patients. To improve the outcomes of patients undergoing a surgery, new adjuvant therapies that can effectively inhibit metastases have to be developed. Studies have shown that flavonoid naringenin, a natural product that is mainly present in grapes and citrus, may contribute to cancer prevention. It has many advantages compared to traditional chemotherapeutic drugs, such as low toxicity. To determine whether naringenin can also inhibit metastases, a breast cancer resection model that mimics clinical situations was established. We found that orally administered naringenin significantly decreased the number of metastatic tumor cells in the lung and extended the life span of tumor resected mice. Flow cytometry analysis revealed that T cells displayed enhanced antitumor activity in naringenin treated mice, with an increased proportion of IFN-γ and IL-2 expressing T cells. In vitro studies further demonstrated that relief of immunosuppression caused by regulatory T cells might be the fundamental mechanism of metastasis inhibition by naringenin. These results indicate that orally administered naringenin can inhibit the outgrowth of metastases after surgery via regulating host immunity. Thus, naringenin can be an ideal surgical adjuvant therapy for breast cancer patients.
Animals ; Anticarcinogenic Agents ; administration & dosage ; therapeutic use ; Antigens, CD ; analysis ; Breast Neoplasms ; drug therapy ; immunology ; pathology ; surgery ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Chemotherapy, Adjuvant ; Female ; Flavanones ; administration & dosage ; therapeutic use ; Humans ; Immunosuppressive Agents ; administration & dosage ; therapeutic use ; Interferon-gamma ; biosynthesis ; immunology ; Interleukin-2 ; biosynthesis ; immunology ; Lung Neoplasms ; drug therapy ; immunology ; prevention & control ; secondary ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; T-Lymphocytes, Regulatory ; drug effects ; immunology ; metabolism

OBJECTIVETo investigate the inhibitory effect of DNA vaccine immunization on neu-overexpressed melanoma growth in prophylactic treatment and anti-lung-metastasis experiments in C57BL/6 mice.

METHODSpcDNA-neu transfected into B16F10 with transfection reagent Fugene 6, neu-overexpressed cell clone B16F10-neu was selected with limited dilution method. The growth curve was drawn to analyse its proliferating character in vitro. With Helios gene gun system, DNA vaccine pWRG-neu was immunized to 8-week-old C57BL/6 mice in the shaved abdominal skin for 3 times at two-weekly interval. After immunization, the life span was analyzed. Using MTT assay, the cytolysis activity of the DNA immunized mice spleen cells was compared.

RESULTSOne clone of neu-overexpressed B16F10-neu was selected and its proliferating character was the same as B16F10 and B16F10-pcDNA. In prophylactic, treatment and anti-lung-metastasis experiments, gene gun-mediated pWRG-neu immunization could exhibit antitumor effects. The growth and metastasis of neu-overexpressed melanoma was reduced dramatically. The spleen cells of the immuned mice showed cytotoxic T lymphocyte (CTL) activity.

CONCLUSIONGene gun-mediated gene transfer is effective and practicable. DNA vaccine pWRG-neu is potent in preventing subsequent tumor cells challenge, inhibiting the tumor growth and metastasis.

Animals ; Biolistics ; Cell Line, Tumor ; Cytotoxicity, Immunologic ; Genes, erbB-2 ; Immunization ; Lung Neoplasms ; prevention & control ; secondary ; Melanoma, Experimental ; metabolism ; pathology ; therapy ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Plasmids ; Receptor, ErbB-2 ; metabolism ; T-Lymphocytes, Cytotoxic ; immunology ; Vaccines, DNA

OBJECTIVETo explore the effects of radiofrequency ablation(RFA) on immune system and lung metastasis in a mouse model of triple negative breast cancer 4T1.

METHODSMouse breast cancer 4T1 cells were injected into the right hind limb of female Bal B/c mice. When the tumor size was 6-8 mm in diameter, RFA was used to treat the transplanted breast cancer in mice. We examined the splenic lymphocyte subsets by flow cytometry at different time points after RFA. Fourteen days after treatment, we sacrificed the mice of both control and treatment groups, counted the number of lung metastatic nodules, and detected the changes of splenic lymphocyte subsets by flow cytometry.

RESULTSRFA basically eliminated the orthotopic carcinoma with a low local recurrence rate. After the RFA treatment, the amount of spleic CD4⁺ T cells, CD8⁺ T cells, B cells, NK and NKT cells was increased. Fourteen days after the RFA treatment, all mice were sacrificed, and the lung metastatic nodules were 24 ± 18 in the control group and 81 ± 35 in the RFA-treated group (P = 0.012). The mechanism of suppression of metastatic lung cancers was related to the increase of splenic CD4⁺ T cells, CD8⁺ T cells, B cells and NK cells, and the decrease of myeloid-derived suppressor cells.

CONCLUSIONSRFA can enhance the anti-tumor immunity and effectively inhibit lung metastasis of 4T1 cell-induced breast cancer, and has a good potential effect in the treatment of triple-negative breast cancer and the control of distant metastasis.

Animals ; B-Lymphocytes ; cytology ; CD4-Positive T-Lymphocytes ; cytology ; CD8-Positive T-Lymphocytes ; cytology ; Catheter Ablation ; Female ; Flow Cytometry ; Humans ; Killer Cells, Natural ; cytology ; Lung Neoplasms ; immunology ; prevention & control ; secondary ; Mice ; Mice, Inbred BALB C ; Neoplasm Recurrence, Local ; Triple Negative Breast Neoplasms ; immunology ; pathology ; surgery ; Tumor Burden