RESUMO
In this study we investigated the efficacy of a combination of IL-12 and 5-FU, a chemotherapeutic exerting several immunomodulatory effects, in murine L1210 leukemia. Mice inoculated with 1 x 10(5) leukemia cells were treated with a single dose of 5-FU (50 mg/kg) and seven daily doses of IL-12 (100 ng/dose), and were observed for survival. Treatment with IL-12 or 5-FU given alone produced moderate anti-leukemic effects. However, combination of both drugs resulted in a significant prolongation of mouse survival time. Importantly, there were 70% of long-term (>60 days) survivors among mice treated with both agents simultaneously. Moreover, we observed 100% of long-term survivors when mice were treated with a minimally increased dose of IL-12 (170 ng) in combination with 5-FU (50 mg/kg). The antileukemic effects were completely abrogated in scid/scid mice and in mice depleted of peritoneal macrophages and significantly decreased after administration of anti-CD3+, anti-CD4+ or anti-CD8+ monoclonal antibodies. Administration of anti-NK1.1 antibodies did not decrease the antileukemic effects indicating that NK cells are not important effectors of this treatment regimen. Collectively, these results indicate that the combination of IL-12 and 5-FU is inducing strong antileukemic responses that are dependent on the presence and activity of macrophages and T lymphocytes and warrant further studies of combined chemo-immunotherapy with IL-12.
Assuntos
Fluoruracila/administração & dosagem , Interleucina-12/administração & dosagem , Leucemia L1210/terapia , Animais , Feminino , Interferon gama/sangue , Células Matadoras Naturais/imunologia , Leucemia L1210/imunologia , Leucemia L1210/mortalidade , Macrófagos/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos SCIDAssuntos
Vetores Genéticos , Imunoterapia/métodos , Neoplasias/terapia , Retroviridae/genética , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/imunologia , Carcinoma de Células Renais/terapia , Expressão Gênica , Terapia Genética/métodos , Humanos , Neoplasias Renais/genética , Neoplasias Renais/imunologia , Neoplasias Renais/terapia , Melanoma/genética , Melanoma/imunologia , Melanoma/terapia , Neoplasias/genética , Neoplasias/imunologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Receptores Virais/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais CultivadasAssuntos
Vacinas Anticâncer/uso terapêutico , Interleucina-6/metabolismo , Melanoma/terapia , Receptores de Interleucina-6/biossíntese , Adulto , Anticorpos Antineoplásicos/biossíntese , Antígenos de Neoplasias/genética , Autoantígenos/genética , Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Feminino , Humanos , Interleucina-6/genética , Isoantígenos/genética , Masculino , Melanoma/genética , Melanoma/imunologia , Antígenos Específicos de Melanoma , Pessoa de Meia-Idade , Monofenol Mono-Oxigenase/genética , Proteínas de Neoplasias/genética , Prognóstico , Receptores de Interleucina-6/genética , SolubilidadeRESUMO
Since melanoma is a model immunogenic malignancy incurable in the disseminated phase of its natural course different immunotherapeutic approaches are tested in clinical trials. A number of tumour vaccines genetically modified (GMTV), with various immunostimulatory factors, are tested in phase I/II clinical trials. These factors include cytokines, tumour antigens (TA), costimulatory molecules or HLA antigens. We have designed a novel, mixed auto/allogeneic cellular melanoma vaccine modified with the IL-6 and the sIL-6R genes. Preclinical studies in a mouse model demonstrated that the IL-6/sIL-6R based vaccine is able to elicit efficient anti-tumour responses, mediated by CD8+ and NK cells, which resulted in inhibition of the tumour growth, metastases formation and prolonged survival of the animals treated. Irradiation of vaccine cells does not only lead to their sterilisation but also causes increased secretion of exogenous IL-6 and sIL-6R. Since January 1996 we have vaccinated more than one hundred metastatic melanoma patients. Promising clinical results (22% CR+PR, 32% SD) and the evidence of immune responses in the vaccinated patients have prompted us to design a phase III clinical trial which is to be open in 2000.
Assuntos
Vacinas Anticâncer/uso terapêutico , Ensaios Clínicos como Assunto , Engenharia Genética , Imunoterapia Ativa , Melanoma/terapia , Vacinas Sintéticas/uso terapêutico , Animais , Vacinas Anticâncer/genética , Vacinas Anticâncer/imunologia , Vacinas Anticâncer/efeitos da radiação , Modelos Animais de Doenças , Humanos , Imunoterapia Ativa/métodos , Interleucina-6/genética , Interleucina-6/imunologia , Melanoma/imunologia , Receptores de Interleucina-6/genética , Receptores de Interleucina-6/imunologia , Solubilidade , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/efeitos da radiaçãoRESUMO
In the present study, TNF-alpha gene-transduced B78 melanoma cells (B78/TNF) were used as a vaccine and combined with interleukin (IL)-12 in the treatment of B78 melanoma-bearing mice. The combined administration of genetically modified melanoma cells and IL-12 induced specific protective antitumor immunity resulting in a decreased rate of the tumor take following a rechallenge with parental B78 cells. When used therapeutically, intratumoral injections of irradiated B78/TNF melanoma cells and IL-12 exerted strong antitumor effects and led to complete regression of established tumors in 50% of mice. Injections of irradiated B78/TNF cells alone did not influence tumor development and IL-12 itself significantly delayed tumor growth but without curative effect. FACS analysis of parental B78 melanoma cells and its B78/TNF genetically modified variant showed that a proportion of cells of both cell lines expressed 87-1 (CD80) costimulatory molecule and that the expression of this molecule was increased during incubation with IFN-gamma. Moreover, IFN-gamma markedly augmented expression of major histocompatibility class (MHC) class I and II molecules on B78/TNF cells that were primarily MHC class I and II negative with no substantial effect on MHC-negative parental B78 melanoma. IFN-gamma also synergized in cytostatic/cytotoxic effects with TNF-alpha against B78 melanoma in vitro. Lymphocyte depletion studies in vivo showed reduction of the antitumor response in mice treated with anti - NK monoclonal antibodies (mAbs) as well as in mice treated with anti-CD4+ anti-CD8 mAbs. The results suggest that, when used therapeutically, IL-12 and a vaccine containing TNF-alpha gene-transduced tumor cells may reciprocally augment their overall antitumor effectiveness by facilitating development of systemic antitumor immunity and by stimulating local effector mechanisms of the tumor destruction.