RESUMEN
Gemcitabine application for patients with impaired renal function or undergoing haemodialysis will increase if the efficacy and safety are proved as the treatment for pancreatic cancer of these patients. However, there is no guideline about the usage of gemcitabine in patients with impaired renal function or haemodialysis. We report the case of a 70-year-old man with advanced pancreatic cancer undergoing haemodialysis. After discontinuation of 100% or 80% dosage, 60% dose of gemcitabine was administered biweekly. Serum carbohydrate antigen 19-9 and carcinoembryonic antigen levels were marked by slight variations and abdominal computed tomography (CT) showed the tumour size hardly changed. We administered gemcitabine for the patient 14 times in total, and he survived over 8 months from the definitive diagnosis. These findings confirm the efficacy and safety of treatment with a biweekly 60% dose of gemcitabine for patients with advanced pancreatic cancer undergoing haemodialysis in the face of dose modification.
Asunto(s)
Antimetabolitos Antineoplásicos/administración & dosificación , Desoxicitidina/análogos & derivados , Neoplasias Pancreáticas/tratamiento farmacológico , Diálisis Renal , Anciano , Desoxicitidina/administración & dosificación , Humanos , Masculino , Tomografía Computarizada por Rayos X , GemcitabinaRESUMEN
Wilms tumor gene (WT1) protein is an attractive target for cancer immunotherapy. We aimed to investigate the feasibility of a combination therapy consisting of gemcitabine and WT1 peptide-based vaccine for patients with advanced pancreatic cancer and to make initial assessments of its clinical efficacy and immunologic response. Thirty-two HLA-A*24:02 patients with advanced pancreatic cancer were enrolled. Patients received HLA-A*24:02-restricted, modified 9-mer WT1 peptide (3 mg/body) emulsified with Montanide ISA51 adjuvant (WT1 vaccine) intradermally biweekly and gemcitabine (1000 mg/m) on days 1, 8, and 15 of a 28-day cycle. This combination therapy was well tolerated. The frequencies of grade 3-4 adverse events for this combination therapy were similar to those for gemcitabine alone. Objective response rate was 20.0% (6/30 evaluable patients). Median survival time and 1-year survival rate were 8.1 months and 29%, respectively. The association between longer survival and positive delayed-type hypersensitivity to WT1 peptide was statistically significant, and longer survivors featured a higher frequency of memory-phenotype WT1-specific cytotoxic T lymphocytes both before and after treatment. WT1 vaccine in combination with gemcitabine was well tolerated for patients with advanced pancreatic cancer. Delayed-type hypersensitivity-positivity to WT1 peptide and a higher frequency of memory-phenotype WT1-specific cytotoxic T lymphocytes could be useful prognostic markers for survival in the combination therapy with gemcitabine and WT1 vaccine. Further clinical investigation is warranted to determine the effectiveness of this combination therapy.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/administración & dosificación , Adenocarcinoma/terapia , Vacunas contra el Cáncer , Neoplasias Pancreáticas/terapia , Fragmentos de Péptidos/administración & dosificación , Linfocitos T Citotóxicos/inmunología , Proteínas Supresoras de Tumor/administración & dosificación , Vacunas de Subunidad/administración & dosificación , Proteínas Adaptadoras Transductoras de Señales/efectos adversos , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Adenocarcinoma/mortalidad , Adulto , Anciano , Células Cultivadas , Desoxicitidina/administración & dosificación , Desoxicitidina/efectos adversos , Desoxicitidina/análogos & derivados , Quimioterapia Combinada , Estudios de Factibilidad , Femenino , Antígeno HLA-A24/metabolismo , Humanos , Hipersensibilidad Tardía/etiología , Memoria Inmunológica , Masculino , Manitol/administración & dosificación , Manitol/efectos adversos , Manitol/análogos & derivados , Persona de Mediana Edad , Metástasis de la Neoplasia , Estadificación de Neoplasias , Ácidos Oléicos/administración & dosificación , Ácidos Oléicos/efectos adversos , Neoplasias Pancreáticas/mortalidad , Fragmentos de Péptidos/efectos adversos , Fragmentos de Péptidos/metabolismo , Análisis de Supervivencia , Proteínas Supresoras de Tumor/efectos adversos , Proteínas Supresoras de Tumor/metabolismo , Vacunas de Subunidad/efectos adversos , GemcitabinaRESUMEN
The therapeutic efficacy of fusion cell (FC)-based cancer vaccine generated with whole tumor cells and dendritic cells (DCs) requires the improved immunogenicity of both cells. Treatment of whole tumor cells with ethanol resulted in blockade of immune-suppressive soluble factors such as transforming growth factor (TGF)-ß1, vascular endothelial growth factor, and IL-10 without decreased expression of major histocompatibility complex (MHC) class I and the MUC1 tumor-associated antigen. Moreover, the ethanol-treated tumor cells expressed "eat-me" signals such as calreticulin (CRT) on the cell surface and released immunostimulatory factors such as heat shock protein (HSP)90α and high-mobility group box 1 (HMGB1). A dual stimulation of protein-bound polysaccharides isolated from Coriolus versicolor (TLR2 agonist) and penicillin-inactivated Streptococcus pyogenes (TLR4 agonist) led human monocyte-derived DCs to produce HSP90α and multiple cytokines such as IL-12p70 and IL-10. Interestingly, incorporating ethanol-treated tumor cells and TLRs-stimulated DCs during the fusion process promoted fusion efficiency and up-regulated MHC class II molecules on a per fusion basis. Moreover, fusions of ethanol-treated tumor cells and dual TLRs-stimulated DCs (E-tumor/FCs) inhibited the production of multiple immune-suppressive soluble factors including TGF-ß1 and up-regulated the production of IL-12p70 and HSP90α. Most importantly, E-tumor/FCs activated T cells capable of producing high levels of IFN-γ, resulting in augmented MUC1-specific CTL induction. Collectively, our results illustrate the synergy between ethanol-treated whole tumor cells and dual TLRs-stimulated DCs in inducing augmented CTL responses in vitro by FC preparations. The alternative system is simple and may provide a platform for adoptive immunotherapy.
Asunto(s)
Células Dendríticas/inmunología , Inmunoterapia Adoptiva , Interleucina-12/biosíntesis , Neoplasias/terapia , Receptores Toll-Like/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Fusión Celular , Línea Celular Tumoral , Citocinas/metabolismo , Etanol/farmacología , Humanos , Factores Inmunológicos/metabolismo , Activación de Linfocitos , Mucina-1/inmunología , Neoplasias/inmunología , Fragmentos de Péptidos/inmunología , Fenotipo , Linfocitos T Citotóxicos/inmunología , Receptores Toll-Like/agonistasRESUMEN
Induction of antitumor immunity by dendritic cell (DC)-tumor fusion cells (DC/tumor) can be modulated by their activation status. In this study, to address optimal status of DC/tumor to induce efficient antigen-specific cytotoxic T lymphocytes (CTLs), we have created various types of DC/tumor: 1) un-activated DC/tumor; 2) penicillin-killed Streptococcus pyogenes (OK-432; TLR4 agonist)-activated DC/tumor; 3) protein-bound polysaccharides isolated from Coriolus versicolor (PSK; TLR2 agonist)-activated DC/tumor; and 4) Combined OK-432- and PSK-activated DC/tumor. Moreover, we assessed the effects of TGF-ß1 derived from DC/tumor on the induction of MUC1-specific CTLs. Combined TLR2- and TLR4-activated DC/tumor overcame immune-suppressive effect of TGF-ß1 in comparison to those single activated or un-activated DC/tumor as demonstrated by: 1) up-regulation of MHC class II and CD86 expression on DC/tumor; 2) increased fusion efficiency; 3) increased production of fusions derived IL-12p70; 4) activation of CD4(+) and CD8(+) T cells that produce high levels of IFN-γ; 5) augmented induction of CTL activity specific for MUC1; and 6) superior efficacy in inhibiting CD4(+)CD25(+)Foxp3(+) T cell generation. However, DC/tumor-derived TGF-ß1 reduced the efficacy of DC/tumor vaccine in vitro. Incorporating combined TLRs-activation and TGF-ß1-blockade of DC/tumor may enhance the effectiveness of DC/tumor-based cancer vaccines and have the potential applicability to the field of adoptive immunotherapy.
Asunto(s)
Células Dendríticas/inmunología , Linfocitos T Citotóxicos/inmunología , Receptor Toll-Like 2/agonistas , Receptor Toll-Like 4/agonistas , Factor de Crecimiento Transformador beta1/farmacología , Antígeno B7-2/genética , Antígeno B7-2/inmunología , Vacunas contra el Cáncer/genética , Vacunas contra el Cáncer/inmunología , Fusión Celular , Línea Celular Tumoral , Células Dendríticas/citología , Células Dendríticas/efectos de los fármacos , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/inmunología , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Interferón gamma/biosíntesis , Interferón gamma/inmunología , Interleucina-12/biosíntesis , Interleucina-12/inmunología , Activación de Linfocitos/efectos de los fármacos , Mucina-1/genética , Mucina-1/inmunología , Picibanil/farmacología , Proteoglicanos/farmacología , Transducción de Señal , Linfocitos T Citotóxicos/citología , Receptor Toll-Like 2/genética , Receptor Toll-Like 2/inmunología , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/inmunología , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
Fusobacterium varium is an elusive pathogenic factor in ulcerative colitis (UC); conventional methods of fecal culture rarely recover F. varium. We have developed a nested culture method to recover Fusobacterium and we used it to investigate whether F. varium could be isolated from UC patients. We enrolled 50 consecutive patients in this study; 26 received combination antibiotic therapy that included amoxicillin, tetracycline, and metronidazole (ATM) for 2 weeks and were thus assigned to the ATM group, and the remaining 24 were assigned to the non-ATM group and did not receive any antibiotics. Stool samples were added to 10 ml of GAM broth that contained neomycin and crystal violet. The samples were vortexed and incubated under anaerobic conditions. The preincubated broth was streaked onto a Fusobacterium-selective agar plate and then incubated under anaerobic conditions. The species of the colonies isolated were identified using the Vitek Automated system and PCR analysis. We recoverd F. varium from 7 of the 24 non-ATM patients (29.2%) and none from the ATM patients (0%) (P = 0.0035). All of the F. varium isolates were susceptible to ATM. This study suggests that the recovery of F. varium is related to UC, which aligns with results from previous studies that used mucosal culture, immunostaining, real-time PCR, and serological studies.
Asunto(s)
Técnicas Bacteriológicas/métodos , Colitis Ulcerosa/diagnóstico , Colitis Ulcerosa/microbiología , Heces/microbiología , Fusobacterium/aislamiento & purificación , Adulto , Anciano , Técnicas de Tipificación Bacteriana , Medios de Cultivo/química , Femenino , Fusobacterium/crecimiento & desarrollo , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , Adulto JovenAsunto(s)
Antineoplásicos/uso terapéutico , Inmunoterapia/métodos , Neoplasias Pancreáticas/terapia , Vacunas contra el Cáncer/inmunología , Vacunas contra el Cáncer/uso terapéutico , Terapia Combinada , Humanos , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/inmunología , Células Madre Neoplásicas/patología , Neoplasias Pancreáticas/inmunología , Neoplasias Pancreáticas/patología , Pronóstico , Resultado del TratamientoRESUMEN
Pancreatic cancer is a highly aggressive and notoriously difficult to treat. As the vast majority of patients are diagnosed at advanced stage of the disease, only a small population is curative by surgical resection. Although gemcitabine-based chemotherapy is typically offered as standard of care, most patients do not survive longer than 6 months. Thus, new therapeutic approaches are needed. Pancreatic cancer cells that develop gemcitabine resistance would still be suitable targets for immunotherapy. Therefore, one promising treatment approach may be immunotherapy that is designed to target pancreatic-cancer-associated antigens. In this paper, we detail recent work in immunotherapy and the advances in concept of combination therapy of immunotherapy and chemotherapy. We offer our perspective on how to increase the clinical efficacy of immunotherapies for pancreatic cancer.
Asunto(s)
Antígenos de Neoplasias/inmunología , Vacunas contra el Cáncer , Quimioterapia , Inmunoterapia , Neoplasias Pancreáticas/tratamiento farmacológico , Animales , Linfocitos T CD8-positivos/inmunología , Terapia Combinada , Citotoxicidad Inmunológica , Células Dendríticas/inmunología , Humanos , Inmunoterapia/tendencias , Activación de Linfocitos , Neoplasias Pancreáticas/inmunología , Resultado del Tratamiento , Escape del TumorRESUMEN
Although dendritic cell (DC)- based cancer vaccines induce effective antitumor activities in murine models, only limited therapeutic results have been obtained in clinical trials. As cancer vaccines induce antitumor activities by eliciting or modifying immune responses in patients with cancer, the Response Evaluation Criteria in Solid Tumors (RECIST) and WHO criteria, designed to detect early effects of cytotoxic chemotherapy in solid tumors, may not provide a complete assessment of cancer vaccines. The problem may, in part, be resolved by carrying out immunologic cellular monitoring, which is one prerequisite for rational development of cancer vaccines. In this review, we will discuss immunologic monitoring of cellular responses for the evaluation of cancer vaccines including fusions of DC and whole tumor cell.
Asunto(s)
Vacunas contra el Cáncer/inmunología , Células Dendríticas/citología , Células Dendríticas/inmunología , Monitorización Inmunológica/métodos , Neoplasias/inmunología , Neoplasias/patología , Animales , Fusión Celular , Humanos , Linfocitos T/inmunologíaRESUMEN
Wilms' tumor gene (WT1), which is expressed in human pancreatic cancer (PC), is a unique tumor antigen recognized by T-cell-mediated antitumor immune response. Gemcitabine (GEM), a standard therapeutic drug for PC, was examined for the regulation of WT1 expression and the sensitizing effect on PC cells with WT1-specific antitumor immune response. Expression of WT1 was examined by quantitative PCR, immunoblot analysis, and confocal microscopy. Antigenic peptide of WT1 presented on HLA class I molecules was detected by mass spectrometry. WT1-specific T-cell receptor gene-transduced human T cells were used as effecter T cells for the analysis of cytotoxic activity. GEM treatment of human MIAPaCa2 PC cells enhanced WT1 mRNA levels, and this increase is associated with nuclear factor kappa B activation. Tumor tissue from GEM-treated MIAPaCa2-bearing SCID mice also showed an increase in WT1 mRNA. Some human PC cell lines other than MIAPaCa2 showed up-regulation of WT1 mRNA levels following GEM treatment. GEM treatment shifted WT1 protein from the nucleus to the cytoplasm, which may promote proteasomal processing of WT1 protein and generation of antigenic peptide. In fact, presentation of HLA-A*2402-restricted antigenic peptide of WT1 (CMTWNQMNL) increased in GEM-treated MIAPaCa2 cells relative to untreated cells. WT1-specific cytotoxic T cells killed MIAPaCa2 cells treated with an optimal dose of GEM more efficiently than untreated MIAPaCa2 cells. GEM enhanced WT1 expression in human PC cells and sensitized PC cells with WT1-specific T-cell-mediated antitumor immune response.
Asunto(s)
Desoxicitidina/análogos & derivados , Neoplasias Pancreáticas/tratamiento farmacológico , Neoplasias Pancreáticas/inmunología , Linfocitos T Citotóxicos/inmunología , Linfocitos T/inmunología , Proteínas WT1/biosíntesis , Proteínas WT1/inmunología , Animales , Presentación de Antígeno , Antimetabolitos Antineoplásicos/farmacología , Procesos de Crecimiento Celular/inmunología , Línea Celular Tumoral , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Citoplasma/efectos de los fármacos , Citoplasma/metabolismo , Desoxicitidina/farmacología , Expresión Génica/efectos de los fármacos , Genes Codificadores de los Receptores de Linfocitos T , Antígeno HLA-A24/inmunología , Humanos , Ratones , Ratones SCID , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Transducción Genética , Regulación hacia Arriba/efectos de los fármacos , Proteínas WT1/genética , Proteínas WT1/metabolismo , GemcitabinaRESUMEN
The goal of cancer vaccines is to induce antitumor immunity that ultimately will reduce tumor burden in tumor environment. Several strategies involving dendritic cells- (DCs)- based vaccine incorporating different tumor-associated antigens to induce antitumor immune responses against tumors have been tested in clinical trials worldwide. Although DCs-based vaccine such as fusions of whole tumor cells and DCs has been proven to be clinically safe and is efficient to enhance antitumor immune responses for inducing effective immune response and for breaking T-cell tolerance to tumor-associated antigens (TAAs), only a limited success has occurred in clinical trials. This paper reviews tumor immune escape and current strategies employed in the field of tumor/DC fusions vaccine aimed at enhancing activation of TAAs-specific cytotoxic T cells in tumor microenvironment.
Asunto(s)
Vacunas contra el Cáncer , Células Dendríticas/inmunología , Activación de Linfocitos , Neoplasias/inmunología , Linfocitos T Citotóxicos/inmunología , Animales , Antígenos de Neoplasias/inmunología , Fusión Celular/métodos , Ensayos Clínicos como Asunto , Humanos , Neoplasias/patología , Neoplasias/terapia , Escape del Tumor/inmunología , Microambiente Tumoral/inmunologíaRESUMEN
Antitumor effects and mechanism of combined therapy with a dendritic cell (DC) vaccine and fluorouracil (5-FU) were investigated. Cytotoxic activity against MC38 cells, untreated or pretreated with 5-FU, was examined in splenocytes from mice inoculated with DCs: DCs pulsed with MC38 lysate or treated with LPS or both and untreated DCs. Inoculation with all types of DCs induced the significant cytotoxic activity of splenocytes, and pretreatment of MC38 cells with 5-FU significantly enhanced the cytotoxic activity of splenocytes. Depletion of natural killer (NK) cells, but not of CD8 or CD4 T cells, in the splenocytes from DC (without MC38 lysate-pulse or LPS treatment thereafter)-inoculated mice decreased the cytotoxic activity. The cytotoxic effect was eliminated by treatment with a monoclonal antibody (mAb) against tumor necrosis factor (TNF)-alpha and was partially inhibited by concanamycin A. Inoculation of mice with DCs upregulated TNFalpha expression on NK cells. MC38 cells pretreated with 5-FU exhibited enhanced expression of procaspase 8 and efficiently underwent apoptosis by TNF-alpha with activation of caspase 8. Although treatment with 5-FU upregulated Rae-1 expression on MC38 cells, the NK-cell-mediated cytotoxic activity was not suppressed by treatment with an anti-Rae-1 mAb or an antinatural killer group 2D mAb or both. These results indicate that combined therapy with a DC vaccine and 5-FU is a promising strategy for cancer treatment mediated by the tumoricidal activity of NK cells through the TNF-alpha pathway.
Asunto(s)
Vacunas contra el Cáncer , Neoplasias Colorrectales/inmunología , Neoplasias Colorrectales/terapia , Células Dendríticas/metabolismo , Inmunoterapia , Animales , Anticuerpos Bloqueadores/farmacología , Presentación de Antígeno , Antígenos de Neoplasias/inmunología , Antígenos de Neoplasias/metabolismo , Extractos Celulares/inmunología , Línea Celular Tumoral , Neoplasias Colorrectales/patología , Neoplasias Colorrectales/fisiopatología , Terapia Combinada , Citotoxicidad Inmunológica/efectos de los fármacos , Células Dendríticas/inmunología , Células Dendríticas/patología , Células Dendríticas/trasplante , Femenino , Fluorouracilo/farmacología , Células Asesinas Naturales/efectos de los fármacos , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Células Asesinas Naturales/patología , Ratones , Ratones Endogámicos C57BL , Trasplante de Neoplasias , Bazo/patología , Factor de Necrosis Tumoral alfa/inmunología , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Fetal calf serum (FCS)-independent pancreatic cancer cells were established in plasma protein fraction (PPF)-supplemented medium that is an agent of good manufacturing practice (GMP) grade. Dendritic cells (DCs) were activated with the Toll-like receptor agonist, penicillin-inactivated Streptococcus pyogenes (OK-432) that is also a GMP grade agent. Therefore, sufficient amounts of FCS-independent fusions were successfully generated with decreased potential hazards of FCS. The FCS-independent fusions expressed tumor-associated antigens, HLA-DR, costimulatory molecules, IL-12, and IL-10. Stimulation of T cells with fusions from healthy donors resulted in proliferation of T cells with high expression levels of perforin/granzyme B and IFN-gamma and efficient induction of antigen-specific cytotoxic T lymphocytes (CTLs). Selection and expansion of T-cell clones were confirmed by TCR Vbeta analysis. However, fusions from patients with metastatic pancreatic cancer induced increased expression levels of TGF-beta1 in CD4+ CD25high T cells and low levels of CTLs with decreased IFN-gamma production.
Asunto(s)
Células Dendríticas/citología , Células Dendríticas/inmunología , Células Híbridas/inmunología , Inmunoterapia/métodos , Neoplasias Pancreáticas/inmunología , Antígenos de Neoplasias/inmunología , Antígenos de Neoplasias/metabolismo , Fusión Celular/métodos , Separación Celular , Células Cultivadas , Citometría de Flujo , Humanos , Activación de Linfocitos/inmunología , Subgrupos de Linfocitos T/inmunología , Linfocitos T/inmunologíaRESUMEN
BACKGROUND: Human hepatocellular carcinoma (HCC) cells express WT1 and/or carcinoembryonic antigen (CEA) as potential targets for the induction of antitumor immunity. In this study, generation of cytotoxic T lymphocytes (CTL) and regulatory T cells (Treg) by fusions of dendritic cells (DCs) and HCC cells was examined. METHODS: HCC cells were fused to DCs either from healthy donors or the HCC patient and investigated whether supernatants derived from the HCC cell culture (HCCsp) influenced on the function of DCs/HCC fusion cells (FCs) and generation of CTL and Treg. RESULTS: FCs coexpressed the HCC cells-derived WT1 and CEA antigens and DCs-derived MHC class II and costimulatory molecules. In addition, FCs were effective in activating CD4+ and CD8+ T cells able to produce IFN-gamma and inducing cytolysis of autologous tumor or semiallogeneic targets by a MHC class I-restricted mechanism. However, HCCsp induced functional impairment of DCs as demonstrated by the down-regulation of MHC class I and II, CD80, CD86, and CD83 molecules. Moreover, the HCCsp-exposed DCs failed to undergo full maturation upon stimulation with the Toll-like receptor 4 agonist penicillin-inactivated Streptococcus pyogenes. Interestingly, fusions of immature DCs generated in the presence of HCCsp and allogeneic HCC cells promoted the generation of CD4+ CD25high Foxp3+ Treg and inhibited CTL induction in the presence of HCCsp. Importantly, up-regulation of MHC class II, CD80, and CD83 on DCs was observed in the patient with advanced HCC after vaccination with autologous FCs. In addition, the FCs induced WT1- and CEA-specific CTL that were able to produce high levels of IFN-gamma. CONCLUSION: The current study is one of the first demonstrating the induction of antigen-specific CTL and the generation of Treg by fusions of DCs and HCC cells. The local tumor-related factors may favor the generation of Treg through the inhibition of DCs maturation; however, fusion cell vaccination results in recovery of the DCs function and induction of antigen-specific CTL responses in vitro. The present study may shed new light about the mechanisms responsible for the generation of CTL and Treg by FCs.
Asunto(s)
Carcinoma Hepatocelular/patología , Fusión Celular/métodos , Células Dendríticas/citología , Neoplasias Hepáticas/patología , Linfocitos T Citotóxicos/citología , Linfocitos T Reguladores/citología , Antígenos CD4/metabolismo , Antígeno Carcinoembrionario/metabolismo , Carcinoma Hepatocelular/inmunología , Diferenciación Celular , Línea Celular Tumoral , Células Dendríticas/inmunología , Factores de Transcripción Forkhead/metabolismo , Humanos , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Neoplasias Hepáticas/inmunología , Masculino , Persona de Mediana Edad , Fenotipo , Fracciones Subcelulares/metabolismo , Linfocitos T Citotóxicos/inmunología , Linfocitos T Reguladores/inmunología , Vacunación , Proteínas WT1/metabolismoRESUMEN
Dendritic cell (DC)/tumor cell fusion cells (FCs) can induce potent CTL responses. The therapeutic efficacy of a vaccine requires the improved immunogenicity of both DCs and tumor cells. The DCs stimulated with the TLR agonist penicillin-killed Streptococcus pyogenes (OK-432; OK-DCs) showed higher expression levels of MHC class I and II, CD80, CD86, CD83, IL-12, and heat shock proteins (HSPs) than did immature DCs. Moreover, heat-treated autologous tumor cells displayed a characteristic phenotype with increased expression of HSPs, carcinoembryonic Ag (CEA), MUC1, and MHC class I (HLA-A2 and/or A24). In this study, we have created four types of FC preparation by alternating fusion cell partners: 1) immature DCs fused with unheated tumor cells; 2) immature DCs fused with heat-treated tumor cells; 3) OK-DCs fused with unheated tumor cells; and 4) OK-DCs fused with heat-treated tumor cells. Although OK-DCs fused with unheated tumor cells efficiently enhanced CTL induction, OK-DCs fused with heat-treated tumor cells were most active, as demonstrated by: 1) up-regulation of multiple HSPs, MHC class I and II, CEA, CD80, CD86, CD83, and IL-12; 2) activation of CD4+ and CD8+ T cells able to produce IFN- gamma at higher levels; 3) efficient induction of CTL activity specific for CEA or MUC1 or both against autologous tumor; and 4) superior abilities to induce CD107+ IFN-gamma+ CD8+ T cells and CD154+ IFN-gamma+ CD4+ T cells. These results strongly suggest that synergism between OK-DCs and heat-treated tumor cells enhances the immunogenicity of FCs and provides a promising means of inducing therapeutic antitumor immunity.