Camptothecin/*pharmacology ; Liver Neoplasms, Experimental/*immunology ; Neoplasm Transplantation ; Sarcoma, Experimental/*immunology ; Transplantation, Isogeneic

Animals ; Camptothecin ; pharmacology ; Liver Neoplasms, Experimental ; immunology ; Mice ; Neoplasm Transplantation ; Sarcoma, Experimental ; immunology ; Transplantation, Isogeneic

Nutritionally supporting the malnourished tumor bearing host may not benefit the disease outcome, but, rather, may preferentially "feed the cancer". We hypothesized that repletion is beneficial only when it augments an anti-tumor immune response. To support this hypothesis, 240 A/J mice were assigned to isocaloric dietary groups (24%, 5%, or 2.5% protein). On day 14 the mice received either immunogenic C1300- neuroblastoma (NB) or non-immunizing TBJ-NB. On day 21 half of the restricted animals were repleted with 24% protein chow. At day 35, chromium-release cell-mediated cytotoxicity was measured. In the group of mice that received 2.5% protein chow, nutritional repletion specifically augmented anti-tumor activity for C1300-NB which elicits a host immune response (33.78 L.U. (repleted) vs 3.47 L.U. (depleted) p less than 0.01), in contrast, nutritional repletion was detrimental for non-immunizing TBJ-NB, where further depression of cytotoxicity was seen (1.37 L.U. (repleted) vs 2.06 L.U. (depleted) 0 less than 0.01). This suggests that the influence of nutritional repletion in tumor nearing animals is dependent on the integrity of host's anti-tumor immunity.
Animals ; Body Weight ; Immunity, Cellular ; Male ; Mice ; Neoplasms, Experimental/*immunology ; Nutrition Disorders/*immunology

In a previous report, it was felt that the rat tumor cell line, T-333, was a mixture of heterogeneous cells with different characteristics with respect to karyotype, tumorigenicity, and response to Rolls Sarcoma virus (RSV) infection. These characteristics of hetero-geneous cell subpopulations could be selected by use of different culture substrates. In this experiment, diversity of the cells in response to complement mediated cytolysis employing syngeneic rat anti-sera was studied. More than 50% of the glass grown cells were lysed while only 19% of the plastic grown cells were lysed by the specific immune sera of syngeneic rats. This finding suggests that growth in plastic culture wares selects cells with resistance to complement mediated cytolysis. It seems likely that the previously reported enhanced tumorigenicity of plastic grown T-333 cells is due to clonal selection of cell subpopulations which can better tolerate at least one arm of the in vivo immune surveillance system.
Animal ; Cells, Cultured ; Cytotoxicity, Immunologic ; Neoplasms, Experimental/immunology* ; Plastics ; Rats ; Rats, Inbred Strains

Animals ; DNA, Complementary ; immunology ; Dendritic Cells ; immunology ; Female ; Liver Neoplasms, Experimental ; immunology ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; Neoplasm Transplantation ; alpha-Fetoproteins ; immunology

The generation of T cells with maximal anti-tumor activities will significantly impact the field of T-cell-based adoptive immunotherapy. In this report, we found that OKT3/IL-2-stimulated T cells were phenotypically more heterogeneous, with enhanced anti-tumor activity in vitro and when locally administered in a solid tumor mouse model. To further improve the OKT3/IL-2-based T cell manufacturing procedure, we developed a novel T cell stimulation and expansion method in which peripheral blood mononuclear cells were electroporated with mRNA encoding a chimeric membrane protein consisting of a single-chain variable fragment against CD3 and the intracellular domains of CD28 and 4-1BB (OKT3-28BB). The expanded T cells were phenotypically and functionally similar to T cells expanded by OKT3/IL-2. Moreover, co-electroporation of CD86 and 4-1BBL could further change the phenotype and enhance the in vivo anti-tumor activity. Although T cells expanded by the co-electroporation of OKT3-28BB with CD86 and 4-1BBL showed an increased central memory phenotype, the T cells still maintained tumor lytic activities as potent as those of OKT3/IL-2 or OKT3-28BB-stimulated T cells. In different tumor mouse models, T cells expanded by OKT3-28BB RNA electroporation showed anti-tumor activities superior to those of OKT3/IL-2 T cells. Hence, T cells with both a less differentiated phenotype and potent tumor killing ability can be generated by RNA electroporation, and this T cell manufacturing procedure can be further optimized by simply co-delivering other splices of RNA, thus providing a simple and cost-effective method for generating high-quality T cells for adoptive immunotherapy.
Animals ; CD28 Antigens ; genetics ; immunology ; Electroporation ; Humans ; Immunity, Cellular ; Interleukin-2 ; immunology ; K562 Cells ; Mice ; Muromonab-CD3 ; immunology ; Neoplasms, Experimental ; genetics ; immunology ; pathology ; RNA, Messenger ; genetics ; immunology ; T-Lymphocytes ; immunology ; Tumor Necrosis Factor Receptor Superfamily, Member 9 ; genetics ; immunology

OBJECTIVETo study the cytotoxic activity against tumor cells and cytokines production of spleen cells induced in vitro by murine 4-1BBL gene transfected Hepa1-6.

METHODSThe eukaryotic expression vector pCDNA3.1(+)-m4-1BBL was transfected into murine hepatocellular carcinoma cell line Hepa1-6 by Liposomes. Then the transfected cells were selected in medium containing G418 (400 - 800 micro g/ml) and termed as Hepa1-6-m4-1BBL. The TCV-m4-1BBL was obtained by treating them with mitomycin (MMC). Cocultivation TCV with syngeneic murine spleen cells, then the lymphocytes were tested for cytotoxic activity against Hepa1-6-wt cells and the supernatants were harvested for detecting the cytokines (IL-2, TNF-alpha and GM-CSF).

RESULTSHepa1-6-m4-1BBL cells expressed 4-1BBL protein with highest cell surface level. The 4-1BBL mRNA could still be detected in the cells when cultured 48 h after treated with MMC (80 mg/L). Comparing with TCV-Hepa1-6, the tumor cell vaccine derived from Hepa1-6-m4-1BBL (TCV-m4-1BBL) could induce a more efficient cytotoxic activity of syngeneic murine lymphocyte against its parental tumor cell Hepa1-6 (P < 0.05), but not against non-parental tumor cell H22 and NIH3T3. Higher levels of IL-2, TNF-alpha and GM-CSF were released by the splencytes after stimulated by TCV-m4-1BBL.

CONCLUSIONSThese results suggest the expression of m4-1BBL by tumor cells is effective in inducing antitumor immune responses.

4-1BB Ligand ; Animals ; Cancer Vaccines ; immunology ; Female ; In Vitro Techniques ; Liver Neoplasms, Experimental ; immunology ; Mice ; Mice, Inbred C57BL ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection ; Tumor Necrosis Factors ; genetics ; physiology

OBJECTIVETo investigate the immunotherapy efficacy of both helper T lymphocytes (Th) and cytotoxic T lymphocytes (CTL) epitopes augmented dendritic cells (DCs) tumor vaccine on gastric cancer.

METHODSNaïve spleen T cells were stimulated by mixed peptides (a mixture of Th epitope MAGE-3 (22-36)) primed DCs per week in vitro. After 4 cycles of restimulation, peptide specific T cells were harvested and subgroups of which were determined with flow cytometry. Cytokines secreting profiles by CD4+ T cells and cytotoxicities of CD8+ T cells on tumor cells were assessed. The protective immunity by referred DCs tumor vaccines was also monitored.

RESULTSBoth Th and CTL epitopes primed DCs could elicit both CD4+ T cells and CD8+ T cells in vitro,of which CD4+ T cells released high amount of Th1 type cytokines (IFN-gamma, IL-2) on recognizing specific antigen, as well as CD8+ T cells exhibited efficient tumor-killing capacity. The effects induced by DCs pulsed with single epitope (Th or CTL epitope) in vivo were less effective than those induced by DCs pulsed with mixture epitopes.

CONCLUSIONSBoth Th and CTL epitopes augmented DCs tumor vaccine can induce CD4+ Th1 and CD8+ CTL mediated immune responses to eradicate gastric cancer cells.

Animals ; Cancer Vaccines ; immunology ; therapeutic use ; Cell Line ; Cell Line, Tumor ; Dendritic Cells ; immunology ; Epitopes, T-Lymphocyte ; immunology ; Immunotherapy ; Melanoma, Experimental ; Mice ; Peptides ; immunology ; Stomach Neoplasms ; therapy ; T-Lymphocytes, Cytotoxic ; immunology ; T-Lymphocytes, Helper-Inducer ; immunology

Human epidermal growth factor receptor 2 (HER2) proteins are overexpressed in a high proportion of gastric cancer (GC) cases and affect the maintenance of cancer stem cell (CSC) subpopulations, which are used as targets for the clinical treatment of patients with HER2-positive GC. Despite improvements in survival, numerous HER2-positive patients fail treatment with trastuzumab, highlighting the need for more effective therapies. In this study, we generated a novel type of genetically modified human T cells, expressing a chimeric antigen receptor (CAR), and targeting the GC cell antigen HER2, which harbors the CD137 and CD3ζ moieties. Our findings show that the expanded CAR-T cells, expressing an increased central memory phenotype, were activated by the specific recognition of HER2 antigens in an MHC-independent manner, and effectively killed patient-derived HER2-positive GC cells. In HER2-positive xenograft tumors, CAR-T cells exhibited considerably enhanced tumor inhibition ability, long-term survival, and homing to targets, compared with those of non-transduced T cells. The sphere-forming ability and in vivo tumorigenicity of patient-derived gastric cancer stem-like cells, expressing HER2 and the CD44 protein, were also inhibited. Our results support the future development and clinical application of this adoptive immunotherapy in patients with HER2-positive advanced GC.
Animals ; Humans ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasms, Experimental ; immunology ; pathology ; therapy ; Receptor, ErbB-2 ; immunology ; Receptors, Antigen, T-Cell ; immunology ; Stomach Neoplasms ; immunology ; pathology ; therapy ; Tumor Cells, Cultured

antibody against tumor specific surface membrane protein was produced by immunizing a New Zealand White rabbit with antigen (66 kDa) prepared from the plasma membrane of rat hepatoma induced by feeding a diet containing 3'-methyl-4-dimethylaminoazobenzene, and was purified by protein A-Sepharose 6MB affinity chromatography. The purified antibody was incorporated into liposomes by a reverse phase evaporation vesicle method in order to prepare a tumor specific anticancer drug carrier. The effect of the antibody against tumor specific antigen was evaluated by comparing the inhibition of DNA synthesis in hepatoma cells with different preparations of methotrexate. Methotrexate encapsulated into liposome showed a stronger inhibitory effect on DNA synthesis (1.4-1.7 times) than free methotrexate. Liposomes having the antibody showed stronger inhibitory effect (3.1 times) on DNA synthesis than free methotrexate group in hepatic nodular area. From these results, it is concluded that tumor specific antibody inserted into liposomal membrane would be recognized by surface antigens which were expressed on the plasma surface membrane of rat hepatoma cells and thereby increase the carrying efficiency of drugs to the target cells. This could be useful in cancer chemotherapy.
Animal ; Antibodies, Neoplasm ; Antigens, Neoplasm/*immunology ; Antigens, Surface/*immunology ; Drug Carriers ; Liposomes ; Liver Neoplasms, Experimental/*drug therapy ; Male ; Methotrexate/*administration and dosage ; Rats ; Support, Non-U.S. Gov't