RESUMEN
Listeria monocytogenes is an intracellular organism that has the unusual ability to live in the cytoplasm of the cell. It is thus a good vector for targeting protein antigens to the cellular arm of the immune response. Here we use a model system, consisting of colon and renal carcinomas that express the influenza virus nucleoprotein and a recombinant L. monocytogenes that secrets this antigen, to test the potential of this organism as a cancer immunotherapeutic agent. We show that this recombinant organism can not only protect mice against lethal challenge with tumour cells that express the antigen, but can also cause regression of established macroscopic tumours in an antigen-specific T-cell-dependent manner.
Asunto(s)
Antígenos de Neoplasias/inmunología , Antineoplásicos/inmunología , Neoplasias del Colon/inmunología , Neoplasias Renales/inmunología , Listeria monocytogenes/inmunología , Vacunas Sintéticas/inmunología , Animales , Especificidad de Anticuerpos , Neoplasias del Colon/prevención & control , Neoplasias Renales/prevención & control , Ratones , Ratones Endogámicos BALB C , Linfocitos T/inmunología , Células Tumorales Cultivadas/inmunologíaRESUMEN
Listeria monocytogenes is a facultative intracellular pathogen that grows in the cytoplasm of infected host cells. We examined the capacity of L. monocytogenes to introduce influenza nucleoprotein (NP) into the class I pathway of antigen presentation both in vitro and in vivo. Recombinant L. monocytogenes secreting a fusion of listeriolysin O and NP (LLO-NP) targeted infected cells for lysis by NP-specific class I-restricted cytotoxic T cells. Antigen presentation occurred in the context of three different class I haplotypes in vitro. A hemolysin-negative L. monocytogenes strain expressing LLO-NP was able to present in a class II-restricted manner. However, it failed to target infected cells for lysis by CD8+ T cells, indicating that hemolysin-dependent bacterial escape from the vacuole is necessary for class I presentation in vitro. Immunization of mice with a recombinant L. monocytogenes strain that stably expressed and secreted LLO-NP induced NP-specific CD8+ cytotoxic T lymphocytes. These studies have implications for the use of L. monocytogenes to deliver potentially any antigen to the class I pathway in vivo.
Asunto(s)
Antígenos Virales/administración & dosificación , Toxinas Bacterianas , Antígenos de Histocompatibilidad Clase I/inmunología , Listeria monocytogenes , Nucleoproteínas/inmunología , Linfocitos T Citotóxicos/inmunología , Proteínas del Núcleo Viral/inmunología , Vacunas Virales/inmunología , Animales , Antígenos Virales/inmunología , Secuencia de Bases , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Línea Celular , Cartilla de ADN , Vectores Genéticos , Proteínas de Choque Térmico/biosíntesis , Proteínas de Choque Térmico/inmunología , Proteínas Hemolisinas , Antígenos de Histocompatibilidad Clase II/inmunología , Listeria monocytogenes/genética , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Nucleoproteínas/biosíntesis , Reacción en Cadena de la Polimerasa , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/inmunología , Recombinación Genética , Células Tumorales Cultivadas , Proteínas del Núcleo Viral/biosíntesisRESUMEN
Listeria monocytogenes has recently been exploited as a vector for targeting antigens to the immune system. In the past year it has been shown to be particularly effective as a tumor antigen vector. Here we set its potency as a cancer vaccine in the context of the type of immunity induced by this facultative intracellular bacterium.
Asunto(s)
Vacunas contra el Cáncer/aislamiento & purificación , Listeria monocytogenes/inmunología , Animales , Presentación de Antígeno , Antígenos de Neoplasias/genética , Citocinas/inmunología , Vectores Genéticos , Interferón gamma/inmunología , Interleucina-1/inmunología , Interleucina-12/inmunología , Listeria monocytogenes/genética , Listeriosis/inmunología , Ratones , Subgrupos de Linfocitos T/inmunología , Factor de Necrosis Tumoral alfa/inmunologíaRESUMEN
We have shown previously that Listeria monocytogenes, a gram-positive, facultative intracellular bacterium, is a potent vector for targeting tumor-specific antigens to the immune system. After parenteral administration, we observed protection against both renal and colorectal mouse tumors and regression of established renal tumors. In the present study, we have exploited the fact that the normal route of infection of this organism is through the gut. We show that an L. monocytogenes recombinant that expresses a model tumor antigen is an effective cancer immunotherapeutic agent when delivered orally in that it causes regression of established, macroscopic mouse renal and colorectal tumors expressing the same antigen.
Asunto(s)
Vacunas Bacterianas/uso terapéutico , Listeria monocytogenes/inmunología , Neoplasias Experimentales/terapia , Proteínas de Unión al ARN , Vacunas Sintéticas/uso terapéutico , Administración Oral , Animales , Antígenos de Neoplasias/inmunología , Antígenos Virales/genética , Antígenos Virales/inmunología , Carcinoma de Células Renales/inmunología , Carcinoma de Células Renales/terapia , Neoplasias del Colon/inmunología , Neoplasias del Colon/terapia , Productos del Gen gag/metabolismo , Inmunoterapia Activa , Neoplasias Renales/inmunología , Neoplasias Renales/terapia , Listeria monocytogenes/genética , Melanoma Experimental/terapia , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Neoplasias Experimentales/inmunología , Proteínas de la Nucleocápside , Nucleoproteínas/inmunología , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Linfocitos T Citotóxicos/inmunología , Transducción Genética , Células Tumorales Cultivadas , Proteínas del Núcleo Viral/inmunologíaRESUMEN
In this study, we evaluate two Listeria monocytogenes strains that express influenza nucleoprotein (NP) sequences for their ability to protect against challenge with influenza-virus. The construction of one strain, which expresses only the Kd restricted NP epitope (NP 147-155), is described in this study; the other strain, which expresses the full NP sequence in the form of a fusion protein, has been described previously. The ability of the two strains to present the Kd restricted NP epitope in vitro and induce NP-specific CTL in vivo is also described. Mice immunized by the intravenous route with either strain cleared a subsequent (3 weeks post-immunization) influenza virus infection more rapidly as indicated by reduced virus titers in the lungs 5 days after challenge. Efficacy of both recombinant L. monocytogenes strains as vaccines in this system was equivalent and equal to that of recombinant vaccinia expressing NP.