BACKGROUNDKilling of targeted tumors during adoptive cell transfer therapy is associated with cytotoxic T lymphocyte (CTL) numbers, immunophenotype, tumor-specificity, and in vivo residence time, migration, and distribution. Therefore, tracing in vivo persistence, migration, and distribution of CTLs is important for cancer immunotherapy.

METHODSOptimal staining concentration for CTL proliferation was determined by cell counting kit-8 (CCK-8) assay and killing efficiencies of CTLs or carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled melanoma antigen-specific cytotoxic T lymphocytes (CFSE-CTLs) for malignant melanoma cells in vitro were compared. Additionally, CFSE-CTLs were intravenously transfused to mice receiving B16 melanoma, and their residence time, migration, and distribution in vivo were observed by measuring fluorescence intensities of CFSE-CTLs per gram of tissue (%FI/g) in various tissues and analyzing tumor/non-tumor (T/NT) values. Anti-tumor effects of transferred CTLs and correlation between %FI/g and D-value of tumor size were analyzed.

RESULTSFive-micromolar CFSE was optimal for labeling CTLs with minimal cytotoxicity. No significant difference occurred between CTLs and CFSE-CTLs for tumor cell killing (P = 0.849) or interleukin-2 (P = 0.318) and interferon-γ (P = 0.201) levels. Distribution of CTLs in vivo varied with time. A negative correlation between %FI/g in tumors and D-value of tumor sizes by Spearman correlation analysis was observed. CTLs were recruited to and killed tumors from 6 hours to 3 days after cell infusion. CTLs were observed up to three weeks later in the tumor, liver, kidneys, and spleen; this was related to the abundant blood supply or the nature of immune organs.

CONCLUSIONSCCK-8 assay is a novel method to select optimal CFSE staining concentrations. Fluorescence intensity of transferred CTLs reflects their killing efficiency of tumors. CFSE fluorescent markers can trace in vivo CTL persistence, migration, and distribution because of its stability, long half-life, and low toxicity.

Adoptive Transfer ; Animals ; Antigens, Neoplasm ; immunology ; Cell Line, Tumor ; Cell Movement ; Female ; Fluoresceins ; Fluorescent Dyes ; Humans ; Lymphocyte Activation ; Melanoma, Experimental ; immunology ; therapy ; Mice ; Mice, Inbred C57BL ; Staining and Labeling ; Succinimides ; T-Lymphocytes, Cytotoxic ; immunology

OBJECTIVETo study the effection of suppression murine melanoma growth by Intratumor injection of recombinant attenuated salmonella carrying heat shock protein 70 and herpes simplex virus thymidine kinase genes.

METHODSPlasmids PCMV-mtHSP70-IRES-TK were electro-transferred into salmonella typhimurium SL7207 to construct recombinant salmonella typhimurium. In vivo, Recombinant bacteria were injected into the mouse melanoma and the antitumor effection was observed. The survival period was recorded and safety analysis for this vaccine in each group.

RESULTSIn vivo, the mtHSP70/HSV-tk recombinant bacteria can suppress tumor growth significantly and extend survival. After recombinant Salmonella, 10(9) CFU/mL, was administered as an intratumoral injection, No diarrhea were observed. During therapy, body weight did not change markedly.

CONCLUSIONResults of the animal experiment suggests intratumor injection of recombinant attenuated salmonella typhimurium containing mtHSP70 and HSV-tk genes, has targeting ability against B16 tumor cell and could significantly inhibit tumor growth .

Animals ; Bacterial Proteins ; genetics ; immunology ; Cancer Vaccines ; genetics ; immunology ; pharmacology ; Genetic Therapy ; methods ; HSP70 Heat-Shock Proteins ; genetics ; immunology ; Melanoma, Experimental ; microbiology ; pathology ; therapy ; Mice ; Mice, Inbred C57BL ; Mycobacterium tuberculosis ; genetics ; Salmonella typhimurium ; genetics ; immunology ; Simplexvirus ; enzymology ; genetics ; Skin Neoplasms ; therapy ; Thymidine Kinase ; genetics ; immunology ; Vaccines, Attenuated ; genetics ; immunology ; pharmacology ; Vaccines, DNA ; genetics ; immunology ; pharmacology

OBJECTIVEThe aim of this study was to construct a new oncolytic virus oHSV2hGM-CSF and evaluate its oncolytic activity in vitro and in vivo in parallel with oHSV1hGM-CSF.

METHODSoHSV2hGM-CSF was a replication-competent, attenuated HSV2 based on the HG52 virus (an HSV2 strain). It was engineered to be specific for cancer by deletion of the viral genes ICP34.5 and ICP47 and insertion of the gene encoding hGM-CSF. To measure the in vitro killing effect of the virus, 15 human tumor cell lines (HeLa, Eca-109, PG, HepG2, SK/FU, CNE-2Z, PC-3, SK-OV3, A-549, 786-0, MCF-7, Hep-2, HT-29, SK-Mel-28, U87-MG) and mouse melanoma (B16R) cell line were seeded into 24-well plates and infected with viruses at MOI = 1 (multiplicity of infection, MOI), or left uninfected. The cells were harvested 24 and 48 hours post infection, and observed under the microscope. For animal studies, the oncolytic viruses were administered intratumorally (at 3-day interval) at a dose of 2.3 x 10(6) PFU (plaque forming unit, PFU) for three times when the tumor volume reached 7-8 mm3. The tumor volume was measured at 3-day intervals and animal survival was recorded.

RESULTSBoth oHSV2hCM-CSFand oHSV1hGM-CSF induced widespread cytopathic effects at 24 h after infection. OHSV2hGM-CSF, by contrast, produced more plaques with a syncytial phenotype than oHSV1hGM-CSF. In the in vitro killing experiments for the cell lines HeLa, HepG2, SK-Mel-28, B16R and U87-MG, oHSV2hGM-CSF eradicated significantly more cells than oHSV1hGM-CSF under the same conditions. For the mouse experiments, it was observed that oHSV2hGM-CSF significantly inhibited the tumor growth. At 15 days after B16R tumor cells inoculation, the tumor volumes of the PBS, oHSV1hGCM-CSF and oHSV2hGM-CSF groups were (374.7 +/- 128.24) mm3, (128.23 +/- 45.32) mm3 (P < 0.05, vs. PBS group) or (10.06 +/- 5.1) mm3 (P < 0.01, vs. PBS group), respectively (mean +/- error). The long term therapeutic effect of oHSV2hGM-CSF on the B16R animal model was evaluated by recording animal survival over 110 days after tumor cells inoculation whereas all the mice in the PBS group died by day 22 (P < 0.01). The anti-tumor mechanism of the newly constructed oHSV2hGM-CSF against B16R cell tumor appeared to include the directly oncolytic activity and the induction of anti-tumor immunity to some degree.

CONCLUSIONThe findings of our study demonstrate that the newly constructed oHSV2hGM-CSF has potent anti-tumor activity in vitro to many tumor cell lines and in vive to the transplanted B16R tumor models.

Animals ; Cell Line, Tumor ; Female ; Gene Deletion ; Genetic Engineering ; Granulocyte-Macrophage Colony-Stimulating Factor ; genetics ; Herpesvirus 2, Human ; genetics ; immunology ; Humans ; Immediate-Early Proteins ; genetics ; metabolism ; Melanoma, Experimental ; pathology ; therapy ; virology ; Mice ; Mice, Inbred C57BL ; Oncolytic Virotherapy ; methods ; Oncolytic Viruses ; genetics ; physiology ; Random Allocation ; Tumor Burden ; Viral Proteins ; genetics ; metabolism ; Xenograft Model Antitumor Assays

BACKGROUNDAdoptive transfer of allogeneic tumor-specific T cells often results in severe graft-versus-host disease (GVHD). Here, we sought to maximize graft-versus-tumor and minimize GVHD by using haploidentical T cells in pre-irradiated B16-melanoma bearing mice.

METHODSC57BL/6 mice bearing B16-melanoma tumors were irradiated with 0, 5, or 7 Gy total body irradiation (TBI), or 7 Gy TBI plus bone marrow transplantation. Tumor areas were measured every 3 days to assess the influence of irradiation treatment on tumor regression. B16-melanoma bearing mice were irradiated with 7 Gy TBI; sera and spleens were harvested at days 1, 3, 5, 7, 9, 11, and 13 after irradiation. White blood cell levels were measured and transforming growth factor β1 (TGF-b1) and interleukin 10 (IL-10) levels in serum were detected using enzyme-linked immunosorbent assay (ELISA) kits. Real-time reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometry were performed to test TGF-b1, IL-10 and Foxp3 mRNA levels and the proportion of CD4+CD25+Foxp3+ T-regulatory cells (Tregs) in spleens. B16-melanoma bearing C57BL/6 mice were irradiated with 7 Gy TBI followed by syngeneic (Syn1/Syn2) or haploidentical (Hap1/Hap2), dendritic cell-induced cytotoxic T lymphocytes (DC-CTLs) treatment, tumor areas and system GVHD were observed every 3 days. Mice were killed 21 days after the DC-CTLs adoptive transfer; histologic analyses of eyes, skin, liver, lungs, and intestine were then performed.

RESULTSIrradiation with 7 Gy TBI on the B16-melanoma-bearing mice did not influence tumor regression compared to the control group; however, it down-regulated the proportion of Tregs in spleens and the TGF-b1 and IL-10 levels in sera and spleens, suggesting inhibition of autoimmunity and intervention of tumor microenvironment. Adoptive transfer of haploidentical DC-CTLs significantly inhibited B16-melanoma growth. GVHD assessment and histology analysis showed no significant difference among the groups.

CONCLUSIONAdoptive transfer of haploidentical tumor-specific T cells in irradiation-pretreated B16-melanoma bearing mice preserved antitumor capacity without causing a GVHD response.

Animals ; Enzyme-Linked Immunosorbent Assay ; Female ; Flow Cytometry ; Graft vs Host Disease ; Immunotherapy, Adoptive ; methods ; Male ; Melanoma, Experimental ; metabolism ; therapy ; Mice ; Mice, Inbred C57BL ; Real-Time Polymerase Chain Reaction ; T-Lymphocytes ; immunology ; T-Lymphocytes, Regulatory ; immunology

Heat shock protein gp96 isolated from tumor tissues holds great promise for tumor immunotherapy. However, at present only very limited amount of gp96 protein can be isolated from tumor tissues. Here, we reconstituted the yeast-expressed gp96 (recombinant gp96, rgp96) with B16.F10 melanoma antigens in vitro to prepare new gp96 tumor vaccine on large-scale, and analyzed its induction of specific anti-tumor immunoresponses by ELISPOT, IFN-gamma intracellular staining and cytotoxicity assays. Immunization with rgp96-tumor antigen complexes significantly inhibited B16 tumor growth compared with either rgp96 or tumor antigens alone and led to enhancement of tumor-specific T-cell activities, which was found similar to that of tumor tissue derived gp96. Our results therefore may provide bases for large-scale preparation of the new generation of gp96 tumor vaccines.
Animals ; Cancer Vaccines ; biosynthesis ; genetics ; immunology ; therapeutic use ; Female ; Heat-Shock Proteins ; biosynthesis ; genetics ; immunology ; therapeutic use ; Melanoma, Experimental ; therapy ; Mice ; Mice, Inbred C57BL ; Neoplasm Transplantation ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; immunology ; therapeutic use ; Skin Neoplasms ; therapy ; Yeasts ; genetics ; metabolism

Secondary lymphoid tissue chemokine (SLC), which is expressed in T cell zones of secondary lymphoid organs, including the spleen and lymph nodes, strongly recruits both T lymphocytes and mature dendritic cells. As appropriate interaction of tumor-specific T cells and mature dendritic cells, equipped with tumor antigens, is a prerequisite for effective T cell immunity against established tumors, we mobilized lymphocytes and dendritic cells to tumor sites by intratumoral injection of secondary lymphoid tissue chemokine-Fc (SLC-Fc) fusion protein using the B16F10 murine melanoma model. Activation of dendritic cells, another prerequisite for the effective activation of naive tumor-specific T cells, was achieved by the addition of immunostimulatory cytosine-phosphorothioate-guanine oligodeoxynucleotide (CpG-ODN) into the tumor site. Intratumoral administration of SLC-Fc or CpG-ODN revealed antitumor effects against B16F10 murine melanoma grown in the subcutaneous space. Co-treatment of SLC-Fc and CpG-ODN displayed synergistic effects in reducing the tumor size. The synergistic antitumor effect in co-treatment group was correlated with the synergistic/additive increase in the infiltration of CD4+ T cells and CD11c+ dendritic cells in the tumor mass compared to the single treatment groups. These results suggest that the combined use of chemokines and adjuvant molecules may be a possible strategy in clinical tumor immunotherapy.
Animals ; Antigens, CD11c/immunology ; CD4-Positive T-Lymphocytes/immunology ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Chemokine CCL21/*administration & dosage/pharmacology ; Chemotaxis, Leukocyte ; Dendritic Cells/immunology/metabolism ; Immunotherapy ; Injections, Intralesional ; Melanoma, Experimental/*immunology/*therapy ; Mice ; Mice, Inbred C57BL ; Oligodeoxyribonucleotides/*administration & dosage/pharmacology ; T-Lymphocytes/immunology/metabolism

OBJECTIVETo improve the anti-tumor effect of dendritic cytoma vaccine (DCV) for finding an effective anti-tumor biotherapy.

METHODSDC vaccine prepared by transfection of adenovirus mediated melanoma-associated antigen gene (gp100) into bone marrow-derived dendritic cell (DC) was used to study the immuno-therapeutic effect and the mechanism of lentinan (LNT) in different dosages, used alone or combined with gp100-DC for treatment of B16 melanoma bearing mice.

RESULTSAfter being treated with LNT combining gp100-DC, the growth of malignant melanoma was inhibited with the tumor-free survival in the experimental animals being 66.7%. The treatment could also significantly enhance the activity of cytotoxicity T lymphocyte (CTL) and natural killer (NK) cells, elevate the levels of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) in splenocytes, and histological examination showed that a large amount of inflammatory cells infiltrated inside and around the tumor, and obvious necrosis of tumor cells was found.

CONCLUSIONBy combined use with LNT the anti-tumor immuno-reaction of DCV vaccine could be enhanced effectively.

Adjuvants, Immunologic ; pharmacology ; therapeutic use ; Animals ; Antineoplastic Agents, Phytogenic ; pharmacology ; therapeutic use ; Cancer Vaccines ; administration & dosage ; immunology ; Cell Line ; Cell Line, Tumor ; Combined Modality Therapy ; Dendritic Cells ; cytology ; immunology ; Female ; Humans ; Lentinan ; pharmacology ; therapeutic use ; Melanoma, Experimental ; immunology ; pathology ; therapy ; Membrane Glycoproteins ; genetics ; immunology ; Mice ; Mice, Inbred C57BL ; Random Allocation ; Shiitake Mushrooms ; chemistry ; Survival Analysis ; Transfection ; gp100 Melanoma Antigen

OBJECTIVETo investigate the enhanced effect of bone marrow-derived dendritic cells (DC) pulsed with SVYDFFVWL, a MHC class I peptide located in 180-188 amino acid residues of human melanoma-associated antigen tyrosinase- related protein 2 ( hTRP2) on the immunity against melanomas elicited by adenovirus encoding hTRP2 (Ad hTRP2).

METHODSThe mice were intradermally immunized with Ad hTRP2, and three weeks later with Ad hTRP2 or DC/SVYDFFVWL once more. Analysis of CTL killing activity and IFN-gamma-producing CD8 + T cells in the total CD8 + T cells of spleen were made using in vivo CTL and intracellular staining of IFN-gamma, respectively. Additionally, the survival of mice was checked after the subcutaneous inoculation with mouse melanoma B16. F10 cells.

RESULTSThe 6 h CTL killing and IFN-gamma producing CD8 +T cells in the total CD8 ' T cells of spleens were 68. 40%+/-5. 50% and 0. 67%+/-0.16% in Ad hTRP2 (priming)-Ad hTRP2 (boosting) group,28. 50%+/-6.40% and 0.22%+/-0.07% in DC/SVYDFFVWL (priming)-DC/ SVYDFFVWL (boosting) group,and 98. 90%+/-0.90% and 1.05%+/-0.21% in Ad hTRP2 (priming)-DC/ SVYDFFVWI, (boosting) group, respectively. In the tumor-bearing model, none of mice survived in DC/SVYDFFVWL (priming)-DC/SVYDFFVWL (boosting) group, and just only 40% of mice were tumor-free in Ad hTRP2 (priming) -Ad hTRP2 (boosting) group, whereas 100% of mice survived in Ad hTRP2 (priming)-DC/SVYDFFVWL (boosting) group.

CONCLUSIONBoosting with DC/ SVYDFFVWL can significantly enhance the immunity against melanomas elicited by priming with Ad hTRP2, indicating that first priming with Ad hTRP2 and then boosting with DC/SVYDFFVWL is a potentially effective regimen for overcoming the disadvantage that anti-tumor immune response can not be significantly increased by readministration of adenovirus.

Adenoviridae ; genetics ; Animals ; CD8-Positive T-Lymphocytes ; immunology ; Cancer Vaccines ; immunology ; Cell Line, Tumor ; Cells, Cultured ; Cytotoxicity Tests, Immunologic ; Dendritic Cells ; cytology ; immunology ; Female ; Genetic Vectors ; genetics ; Humans ; Immunization, Secondary ; methods ; Intramolecular Oxidoreductases ; immunology ; Melanoma, Experimental ; immunology ; pathology ; therapy ; Membrane Proteins ; immunology ; Mice ; Mice, Inbred C57BL ; Peptide Fragments ; immunology ; Survival Analysis ; T-Lymphocytes, Cytotoxic ; immunology

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

OBJECTIVETo test whether vaccination performed during irradiation or chemotherapeutics-induced lymphopenia-driven T cell proliferation could augment the antitumor immunity.

METHODSThe study composed of two parts, investigating the anti-tumor efficacy of performing tumor vaccination during early immune reconstitution period following sublethal total body irradiation and cyclophosphamide (Cy)-induced lymphopenia, respectively. Mice were subsequently reconstituted with naïve splenocytes from syngeneic mice and were named RLM (Reconstituted lymphopenic mice). Immunization/vaccination (F10) and adoptive immunotherapy (D5-G6) were used to explore anti-tumor immune responses in vaccinated irradiation/RLM and vaccinated Cy/RLM, respectively. Both normal C57BL/6 mice and RLM were vaccinated with irradiated, weakly immunogenic F10 melanoma cells and subsequently challenged with F10 cells. In addition, to determine the role of CD4(+) and CD8(+) T cells in the protective anti-tumor immune response, irradiation/RLM were depleted of these subpopulations by administration of the appropriate mAb around challenge. In the second part, adoptive immunotherapy was used to evaluate the anti-tumor immune responses under chemotherapeutics-induced lymphopenic condition. Both normal mice and RLM (Cy-treated) were vaccinated with GM-CSF-modified D5 melanoma cells (D5-G6) and tumor vaccine draining lymph nodes (TVDLN) were harvested 9-10 days later. Effector T cells were generated in vitro from TVDLN cells and adoptively transferred to mice bearing 3-day pre-established pulmonary metastases (D5). Recipient mice were sacrificed 2 weeks later after tumor inoculation and pulmonary metastases were enumerated.

RESULTSSignificantly greater protection was induced in vaccinated irradiation/RLM, compared to vaccinated normal mice (63.2% vs 16.7%). Protective immunity in RLM depended on CD8(+) T cells. Increase in the interval between reconstitution and vaccination significantly decrease the protection. Effector T cells generated from vaccinated Cy-treated RLM demonstrated significantly higher in vivo anti-tumor efficacy over those of vaccinated normal mice.

CONCLUSIONThis study suggests that vaccination of RLM could elicit augmented antitumor immunity compared to normal hosts, highlighting the potential clinical benefit of performing tumor vaccination during irradiation or chemotherapeutics-induced lymphopenia in cancer patients.

Animals ; CD8-Positive T-Lymphocytes ; immunology ; Cancer Vaccines ; therapeutic use ; Cyclophosphamide ; adverse effects ; Female ; Granulocyte-Macrophage Colony-Stimulating Factor ; immunology ; Immunotherapy, Adoptive ; methods ; Lymphopenia ; etiology ; therapy ; Melanoma, Experimental ; drug therapy ; immunology ; radiotherapy ; Mice ; Mice, Inbred C57BL ; Whole-Body Irradiation