RESUMEN
Syrian hamsters are permissive for the replication of species C human adenoviruses (HAdV-C). The virus replicates to high titers in the liver of these animals after intravenous infection, while respiratory infection results in virus replication in the lung. Here we show that two types belonging to species C, HAdV-C5 and HAdV-C6, replicate to significantly different extents and cause pathology with significantly different severities, with HAdV-C6 replicating better and inducing more severe and more widespread lesions. The virus burdens in the livers of HAdV-C6-infected hamsters are higher than the virus burdens in HAdV-C5-infected ones because more of the permissive hepatocytes get infected. Furthermore, when hamsters are infected intravenously with HAdV-C6, live, infectious virus can be isolated from the lung and the kidney, which is not seen with HAdV-C5. Similarly to mouse models, in hamsters, HAdV-C6 is sequestered by macrophages to a lesser degree than HAdV-C5. Depletion of Kupffer cells from the liver greatly increases the replication of HAdV-C5 in the liver, while it has only a modest effect on the replication of HAdV-C6. Elimination of Kupffer cells also dramatically increases the pathology induced by HAdV-C5. These findings indicate that in hamsters, pathology resulting from intravenous infection with adenoviruses is caused mostly by replication in hepatocytes and not by the abortive infection of Kupffer cells and the following cytokine storm.IMPORTANCE Immunocompromised human patients can develop severe, often lethal adenovirus infections. Respiratory adenovirus infection among military recruits is a serious problem, in some cases requiring hospitalization of the patient. Furthermore, adenovirus-based vectors are frequently used as experimental viral therapeutic agents. Thus, it is imperative that we investigate the pathogenesis of adenoviruses in a permissive animal model. Syrian hamsters are susceptible to infection with certain human adenoviruses, and the pathology accompanying these infections is similar to what is observed with adenovirus-infected human patients. We demonstrate that replication in permissive cells in a susceptible host animal is a major part of the mechanism by which systemic adenovirus infection induces pathology, as opposed to the chiefly immune-mediated pathology observed in nonsusceptible hosts. These findings support the use of compounds inhibiting adenovirus replication as a means to block adenovirus-induced pathology.
Asunto(s)
Infecciones por Adenovirus Humanos/patología , Infecciones por Adenovirus Humanos/virología , Adenovirus Humanos/patogenicidad , Hígado/virología , Carga Viral , Replicación Viral , Adenovirus Humanos/clasificación , Adenovirus Humanos/fisiología , Animales , Línea Celular , Cricetinae , Modelos Animales de Enfermedad , Humanos , Riñón/virología , Macrófagos del Hígado/virología , Hígado/patología , Pulmón/virología , Macrófagos/virología , MesocricetusRESUMEN
[This corrects the article DOI: 10.1371/journal.ppat.1005084.].
RESUMEN
Human adenoviruses have been studied extensively in cell culture and have been a model for studies in molecular, cellular, and medical biology. However, much less is known about adenovirus replication and pathogenesis in vivo in a permissive host because of the lack of an adequate animal model. Presently, the most frequently used permissive immunocompetent animal model for human adenovirus infection is the Syrian hamster. Species C human adenoviruses replicate in these animals and cause pathology that is similar to that seen with humans. Here, we report findings with a new Syrian hamster strain in which the STAT2 gene was functionally knocked out by site-specific gene targeting. Adenovirus-infected STAT2 knockout hamsters demonstrated an accentuated pathology compared to the wild-type control animals, and the virus load in the organs of STAT2 knockout animals was 100- to 1000-fold higher than that in wild-type hamsters. Notably, the adaptive immune response to adenovirus is not adversely affected in STAT2 knockout hamsters, and surviving hamsters cleared the infection by 7 to 10 days post challenge. We show that the Type I interferon pathway is disrupted in these hamsters, revealing the critical role of interferon-stimulated genes in controlling adenovirus infection. This is the first study to report findings with a genetically modified Syrian hamster infected with a virus. Further, this is the first study to show that the Type I interferon pathway plays a role in inhibiting human adenovirus replication in a permissive animal model. Besides providing an insight into adenovirus infection in humans, our results are also interesting from the perspective of the animal model: STAT2 knockout Syrian hamster may also be an important animal model for studying other viral infections, including Ebola-, hanta-, and dengue viruses, where Type I interferon-mediated innate immunity prevents wild type hamsters from being effectively infected to be used as animal models.
Asunto(s)
Infecciones por Adenoviridae/inmunología , Adenovirus Humanos/patogenicidad , Modelos Animales de Enfermedad , Interferón Tipo I/inmunología , Factor de Transcripción STAT2/deficiencia , Infecciones por Adenoviridae/patología , Adenovirus Humanos/inmunología , Animales , Animales Modificados Genéticamente , Línea Celular Tumoral , Cricetinae , Citometría de Flujo , Técnicas de Inactivación de Genes , Humanos , Mesocricetus , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción STAT2/inmunologíaRESUMEN
Interleukin-12 is a potent activator and initiator of type-1 T cell development, and can be used as an adjuvant to bias for the development of vaccine-induced Th1 immune responses. During vaccination of MHC class I deficient beta-2 microglobulin knockout mice (ß2M(-/-)) with an IL-12/αIL-4 Th1 biasing procedure, all of the mice died. None of the IL-12/αIL-4 treated wild type mice developed any noticeable complications. We hypothesized that NK cells may be activated by IL-12 treatment in these ß2M(-/-) mice, leading to necrosis and eventual death. IL-12/αIL-4 treatment of ß2M(-/-) mice resulted in increased NK cell numbers and activation status (IFN-γ(+), CD69(+)). Finally, in vivo depletion of NK cells reversed the pathology induced by IL-12/αIL-4 treatment in ß2M deficient mice. These results indicate that IL-12 combined with αIL-4 irreversibly activates NK cells leading to a disseminated inflammatory pathology and death in ß2M(-/-) mice.
Asunto(s)
Antígenos de Histocompatibilidad Clase I/genética , Inflamación/inmunología , Interleucina-12/efectos adversos , Subunidad alfa del Receptor de Interleucina-4/inmunología , Células Asesinas Naturales/efectos de los fármacos , Microglobulina beta-2/inmunología , Animales , Antígenos CD/inmunología , Antígenos de Diferenciación de Linfocitos T/inmunología , Proliferación Celular , Antígenos de Histocompatibilidad Clase I/inmunología , Interferón gamma/inmunología , Interleucina-12/administración & dosificación , Células Asesinas Naturales/inmunología , Lectinas Tipo C/inmunología , Ratones , Ratones Noqueados , Células TH1/inmunología , Microglobulina beta-2/genéticaRESUMEN
Humanized liver chimeric mice (PXB-mice) are generated by the transplantation of human hepatocytes into mice that have severe combined immunodeficiency and express an albumin-promoted urokinase-type plasminogen activator (cDNA-uPA/SCID) transgene. Human hepatocytes cannot synthesize ascorbic acid (AA; commonly called vitamin C) and humans require supplementation to prevent vitamin C deficiency. PXB-mouse livers contain up to approximately 95% human hepatocytes, which likely affects AA synthesis. To determine whether dietary AA supplementation prevents scurvy-like symptoms and death in PXB-mice, a 12 week study that compared nonsupplemented and supplemented PXB-mice was conducted. Approximately 4 weeks into the study, PXB-mice without dietary supplementation of AA displayed weight loss and clinical signs of hypovitaminosis C, including hunched posture, unkempt appearance, and lameness. Pathologic evaluation of nonsupplemented PXB-mice revealed lesions consistent with hypovitaminosis C. Mean serum AA concentrations in the nonsupplemented PXB-mice were below the limit of quantitation (0.5 µg/mL) and were substantially less than those of controls. AA was also measured in a number of tissues, including adrenal gland, brain, liver, and testis; low AA concentrations were similarly observed in tissues obtained from the nonsupplemented PXB-mice. Collectively, these findings support AA supplementation in PXB-mice to prevent the development of hypovitaminosis C and the potential utility of nonsupplemented PXB-mice as an animal model of scurvy.
Asunto(s)
Escorbuto , Masculino , Ratones , Humanos , Animales , Ratones SCID , Hígado , Hepatocitos , Modelos AnimalesRESUMEN
Monkeypox virus (MPXV) is an orthopoxvirus closely related to variola, the etiological agent of smallpox. In humans, MPXV causes a disease similar to smallpox and is considered to be an emerging infectious disease. Moreover, the use of MPXV for bioterroristic/biowarfare activities is of significant concern. Available small animal models of human monkeypox have been restricted to mammals with poorly defined biologies that also have limited reagent availability. We have established a murine MPXV model utilizing the STAT1-deficient C57BL/6 mouse. Here we report that a relatively low-dose intranasal (IN) infection induces 100% mortality in the stat1(-)(/)(-) model by day 10 postinfection with high infectious titers in the livers, spleens, and lungs of moribund animals. Vaccination with modified vaccinia virus Ankara (MVA) followed by a booster vaccination is sufficient to protect against an intranasal MPXV challenge and induces an immune response more robust than that of a single vaccination. Furthermore, antiviral treatment with CMX001 (HDP-cidofovir) and ST-246 protects when administered as a regimen initiated on the day of infection. Thus, the stat1(-)(/)(-) model provides a lethal murine platform for evaluating therapeutics and for investigating the immunological and pathological responses to MPXV infection.
Asunto(s)
Modelos Animales de Enfermedad , Monkeypox virus/efectos de los fármacos , Monkeypox virus/patogenicidad , Mpox/tratamiento farmacológico , Mpox/prevención & control , Animales , Antivirales/uso terapéutico , Benzamidas , Citosina/análogos & derivados , Citosina/uso terapéutico , Femenino , Humanos , Isoindoles , Hígado/virología , Pulmón/virología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mpox/mortalidad , Organofosfonatos/uso terapéutico , Factor de Transcripción STAT1/deficiencia , Vacuna contra Viruela/inmunología , Bazo/virología , Análisis de Supervivencia , Resultado del Tratamiento , Virus Vaccinia/inmunología , Carga ViralRESUMEN
Adenoviruses (Ads) cause a wide array of end-organ and disseminated diseases in severely immunosuppressed patients. For example, approximately 20% of pediatric allogeneic hematopoietic stem cell transplant recipients develop disseminated Ad infection, and the disease proves fatal in as many as 50-80% of these patients. Ad infections are a serious problem for solid-organ transplant recipients and AIDS patients as well. Unfortunately, there are no antiviral drugs approved specifically to treat these infections. A suitable animal model that is permissive for Ad replication would help in the discovery process. Here we identify an animal model to study Ad pathogenesis and the efficacy of antiviral compounds. We show that human serotype 5 Ad (Ad5) causes severe systemic disease in immunosuppressed Syrian hamsters that is similar to that seen in immunocompromised patients. We also demonstrate that hexadecyloxypropyl-cidofovir (CMX001) rescues the hamsters from a lethal challenge with Ad5. The antiviral drug provided protection both prophylactically and when given up to 2 days after i.v. exposure to Ad5. CMX001 acts by reducing Ad replication in key target organs. Thus, the immunosuppressed Syrian hamster is a powerful model to evaluate anti-Ad drugs, and its use can facilitate the entry of drugs such as CMX001 into clinical trials.
Asunto(s)
Citosina/análogos & derivados , Inmunosupresores/uso terapéutico , Organofosfonatos/farmacología , Adenoviridae/metabolismo , Infecciones por Adenoviridae/metabolismo , Infecciones por Adenoviridae/terapia , Animales , Antivirales/farmacología , Cricetinae , Citosina/farmacología , Modelos Animales de Enfermedad , Ensayos de Selección de Medicamentos Antitumorales , Células Madre Hematopoyéticas/citología , Humanos , Hígado/metabolismo , Mesocricetus , Modelos BiológicosRESUMEN
Chronic hepatitis B virus (HBV) infection is a major public health problem. New treatment approaches are needed because current treatments do not target covalently closed circular DNA (cccDNA), the template for HBV replication, and rarely clear the virus. We harnessed adeno-associated virus (AAV) vectors and CRISPR-Staphylococcus aureus (Sa)Cas9 to edit the HBV genome in liver-humanized FRG mice chronically infected with HBV and receiving entecavir. Gene editing was detected in livers of five of eight HBV-specific AAV-SaCas9-treated mice, but not control mice, and mice with detectable HBV gene editing showed higher levels of SaCas9 delivery to HBV+ human hepatocytes than those without gene editing. HBV-specific AAV-SaCas9 therapy significantly improved survival of human hepatocytes, showed a trend toward decreasing total liver HBV DNA and cccDNA, and was well tolerated. This work provides evidence for the feasibility and safety of in vivo gene editing for chronic HBV infections, and it suggests that with further optimization, this approach may offer a plausible way to treat or even cure chronic HBV infections.
RESUMEN
Exposure to moderately selective p38alpha mitogen-activated protein kinase (MAPK) inhibitors in the Beagle dog results in an acute toxicity consisting of mild clinical signs (decreased activity, diarrhea, and fever), lymphoid necrosis and depletion in the gut-associated lymphoid tissue (GALT), mesenteric lymph nodes and spleen, and linear colonic and cecal mucosal hemorrhages. Lymphocyte apoptosis and necrosis in the GALT is the earliest and most prominent histopathologic change observed, followed temporally by neutrophilic infiltration and acute inflammation of the lymph nodes and spleen and multifocal mucosal epithelial necrosis and linear hemorrhages in the colon and cecum. These effects are not observed in the mouse, rat, or cynomolgus monkey. To further characterize the acute toxicity in the dog, a series of in vivo, in vitro, and immunohistochemical studies were conducted to determine the relationship between the lymphoid and gastrointestinal (GI) toxicity and p38 MAPK inhibition. Results of these studies demonstrate a direct correlation between p38alpha MAPK inhibition and the acute lymphoid and gastrointestinal toxicity in the dog. Similar effects were observed following exposure to inhibitors of MAPK-activated protein kinase-2 (MK2), further implicating the role of p38alpha MAPK signaling pathway inhibition in these effects. Based on these findings, the authors conclude that p38alpha MAPK inhibition results in acute lymphoid and GI toxicity in the dog and is unique among the species evaluated in these studies.
Asunto(s)
Enfermedades Gastrointestinales/inducido químicamente , Péptidos y Proteínas de Señalización Intracelular/antagonistas & inhibidores , Enfermedades Linfáticas/inducido químicamente , Inhibidores de Proteínas Quinasas/toxicidad , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidores , Animales , Linfocitos B/metabolismo , Western Blotting , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Colon/efectos de los fármacos , Colon/patología , Perros , Femenino , Enfermedades Gastrointestinales/patología , Hemorragia Gastrointestinal/inducido químicamente , Humanos , Inmunohistoquímica , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Modelos Lineales , Ganglios Linfáticos/efectos de los fármacos , Ganglios Linfáticos/patología , Enfermedades Linfáticas/patología , Macaca fascicularis , Masculino , Ratones , Proteínas Serina-Treonina Quinasas/metabolismo , Ratas , Ratas Sprague-Dawley , Bazo/citología , Bazo/metabolismo , Linfocitos T/metabolismo , Pruebas de Toxicidad Aguda , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
Toxicity is a leading cause of attrition at all stages of the drug development process. The majority of safety-related attrition occurs preclinically, suggesting that approaches to identify 'predictable' preclinical safety liabilities earlier in the drug development process could lead to the design and/or selection of better drug candidates that have increased probabilities of becoming marketed drugs. In this Review, we discuss how the early application of preclinical safety assessment--both new molecular technologies as well as more established approaches such as standard repeat-dose rodent toxicology studies--can identify predictable safety issues earlier in the testing paradigm. The earlier identification of dose-limiting toxicities will provide chemists and toxicologists the opportunity to characterize the dose-limiting toxicities, determine structure-toxicity relationships and minimize or circumvent adverse safety liabilities.
Asunto(s)
Diseño de Fármacos , Tecnología Farmacéutica/métodos , Animales , Ensayos Clínicos como Asunto , Evaluación Preclínica de Medicamentos/métodos , Humanos , Modelos Biológicos , Farmacogenética/métodos , Pruebas de ToxicidadRESUMEN
We recently described an immunocompetent Syrian hamster model for oncolytic adenoviruses (Ads) that permits virus replication in tumor cells as well as some normal tissues. This model allows exploration of interactions between the virus, tumor, normal organs, and host immune system that could not be examined in the immunodeficient or nonpermissive animal models previously used in the oncolytic Ad field. Here we asked whether the immune response to oncolytic Ad enhances or limits antitumor efficacy. We first determined that cyclophosphamide (CP) is a potent immunosuppressive agent in the Syrian hamster and that CP alone had no effect on tumor growth. Importantly, we found that the antitumor efficacy of oncolytic Ads was significantly enhanced in immunosuppressed animals. In animals that received virus therapy plus immunosuppression, significant differences were observed in tumor histology, and in many cases little viable tumor remained. Notably, we also determined that immunosuppression allowed intratumoral virus levels to remain elevated for prolonged periods. Although favorable tumor responses can be achieved in immunocompetent animals, the rate of virus clearance from the tumor may lead to varied antitumor efficacy. Immunosuppression, therefore, allows sustained Ad replication and oncolysis, which leads to substantially improved suppression of tumor growth.
Asunto(s)
Adenoviridae/genética , Neoplasias Experimentales/terapia , Viroterapia Oncolítica , Replicación Viral/inmunología , Adenoviridae/inmunología , Adenoviridae/fisiología , Animales , Antineoplásicos/uso terapéutico , División Celular , Cricetinae , Ciclofosfamida/uso terapéutico , Inmunohistoquímica , Mesocricetus , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/inmunología , Neoplasias Experimentales/patología , Pruebas de NeutralizaciónRESUMEN
Chronic hepatitis B virus infection cannot be cured by current therapies, so new treatments are urgently needed. We recently identified novel inhibitors of the hepatitis B virus ribonuclease H that suppress viral replication in cell culture. Here, we employed immunodeficient FRG KO mice whose livers had been engrafted with primary human hepatocytes to ask whether ribonuclease H inhibitors can suppress hepatitis B virus replication in vivo. Humanized FRG KO mice infected with hepatitis B virus were treated for two weeks with the ribonuclease H inhibitors #110, an α-hydroxytropolone, and #208, an N-hydroxypyridinedione. Hepatitis B virus viral titers and S and e antigen plasma levels were measured. Treatment with #110 and #208 caused significant reductions in plasma viremia without affecting hepatitis B virus S or e antigen levels, and viral titers rebounded following treatment cessation. This is the expected pattern for inhibitors of viral DNA synthesis. Compound #208 suppressed viral titers of both hepatitis B virus genotype A and C isolates. These data indicate that Hepatitis B virus replication can be suppressed during infection in an animal by inhibiting the viral ribonuclease H, validating the ribonuclease H as a novel target for antiviral drug development.
Asunto(s)
Antivirales/farmacología , Virus de la Hepatitis B/efectos de los fármacos , Virus de la Hepatitis B/fisiología , Ribonucleasa H/antagonistas & inhibidores , Replicación Viral/efectos de los fármacos , Animales , Antivirales/administración & dosificación , Antivirales/farmacocinética , Replicación del ADN/efectos de los fármacos , Genotipo , Hepatitis B/tratamiento farmacológico , Hepatitis B/virología , Humanos , Ratones , Ratones Noqueados , Ratones Transgénicos , Proyectos Piloto , Resultado del TratamientoRESUMEN
Adenovirus infections of immunocompromised pediatric hematopoietic stem cell transplant patients can develop into serious and often deadly multi-organ disease. There are no drugs approved for adenovirus infections. Cidofovir (an analog of 2-deoxycytidine monophosphate) is used at times but it can be nephrotoxic and its efficacy has not been proven in clinical trials. Brincidofovir, a promising lipid-linked derivative of cidofovir, is in clinical trials. Ganciclovir, an analog of 2-deoxyguanosine, has been employed occasionally but with unknown efficacy in the clinic. In this study, we evaluated valganciclovir against disseminated adenovirus type 5 (Ad5) infection in our permissive immunosuppressed Syrian hamster model. We administered valganciclovir prophylactically, beginning 12 h pre-infection or therapeutically starting at Day 1, 2, 3, or 4 post-infection. Valganciclovir significantly increased survival, reduced viral replication in the liver, and mitigated the pathology associated with Ad5 infection. In cultured cells, valganciclovir inhibited Ad5 DNA replication and blocked the transition from early to late stage of infection. Valganciclovir directly inhibited Ad5 DNA polymerase in vitro, which may explain, at least in part, its mechanism of action. Ganciclovir and valganciclovir are approved to treat infections by certain herpesviruses. Our results support the use of valganciclovir to treat disseminated adenovirus infections in immunosuppressed patients.
Asunto(s)
Infecciones por Adenovirus Humanos/tratamiento farmacológico , Infecciones por Adenovirus Humanos/patología , Adenovirus Humanos/efectos de los fármacos , Antivirales/uso terapéutico , Ganciclovir/análogos & derivados , Huésped Inmunocomprometido , Replicación Viral/efectos de los fármacos , Adenovirus Humanos/fisiología , Animales , Antivirales/farmacología , Línea Celular , ADN Polimerasa Dirigida por ADN/metabolismo , Modelos Animales de Enfermedad , Células Epiteliales/virología , Femenino , Ganciclovir/farmacología , Ganciclovir/uso terapéutico , Humanos , Hígado/virología , Masculino , Mesocricetus , Análisis de Supervivencia , Resultado del Tratamiento , Valganciclovir , Carga ViralRESUMEN
Epididymal cribriform hyperplasia (ECH) is a variant of normal epididymal histologic features in men, and has also been reported in rats, mice, dogs, cats, and bulls. The epididymal change has been associated with aging, testicular atrophy, cryptorchidism, and germ cell tumors. Epididymal cribriform hyperplasia was observed in p53 homozygous knockout mice on a mixed 129/Sv-FVB/N background, but not in wild-type or heterozygous mice. The aim of the study reported here was to determine the prevalence and characterize the morphologic, immunohistochemical, and ultrastructural features of ECH in these mice. Epididymal cribriform hyperplasia was present in 88% (72/82) of male mice ranging in age from seven to 65 weeks. The lesion was characterized microscopically by epithelial cells with atypical hyperchromatic nuclei, vacuolization, intratubular lumina formation, infrequent apoptosis, and rare mitotic figures. In contrast to germ cells, the cells of ECH did not express alpha-fetoprotein, carcinoembryonic antigen, or S-100. Ultrastructurally, the cells were pleomorphic with stereocilia at their apical borders and within intratubular lumina, and were supported by a basement membrane. Although 14% (10/72) of mice had concomitant testicular neoplasia, ECH did not appear to be a preneoplastic change. Investigators using these mice for modeling human disease should be aware of the background prevalence of this lesion.
Asunto(s)
Núcleo Celular/patología , Epidídimo/patología , Enfermedades Testiculares/patología , Proteína p53 Supresora de Tumor/genética , Factores de Edad , Animales , Cruzamiento , ADN/análisis , Cartilla de ADN/química , Modelos Animales de Enfermedad , Epidídimo/metabolismo , Células Epiteliales/ultraestructura , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Genotipo , Homocigoto , Hiperplasia/patología , Técnicas para Inmunoenzimas , Masculino , Ratones , Ratones Noqueados , Reacción en Cadena de la Polimerasa , Enfermedades Testiculares/metabolismo , Proteína p53 Supresora de Tumor/metabolismoRESUMEN
Chronic inflammation is a major risk factor for cancer, including gastric cancers and other gastrointestinal cancers. For example, chronic inflammation caused by autoimmune gastritis (AIG) is associated with an increased risk of gastric polyps, gastric carcinoid tumors, and possibly adenocarcinomas. In this study, we characterized the progression of gastric cancer in a novel mouse model of AIG. In this model, disease was caused by CD4(+) T cells expressing a transgenic T-cell receptor specific for a peptide from the H(+)/K(+) ATPase proton pump, a protein expressed by parietal cells in the stomach. AIG caused epithelial cell aberrations that mimicked most of those seen in progression of human gastric cancers, including chronic gastritis followed by oxyntic atrophy, mucous neck cell hyperplasia, spasmolytic polypeptide-expressing metaplasia, dysplasia, and ultimately gastric intraepithelial neoplasias. Our work provides the first direct evidence that AIG supports the development of gastric neoplasia and provides a useful model to study how inflammation drives gastric cancer.
Asunto(s)
Enfermedades Autoinmunes/etiología , Linfocitos T CD4-Positivos/inmunología , Gastritis/complicaciones , ATPasa Intercambiadora de Hidrógeno-Potásio/inmunología , Inflamación/complicaciones , Receptores de Antígenos de Linfocitos T/fisiología , Neoplasias Gástricas/etiología , Adenocarcinoma/etiología , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Animales , Enfermedades Autoinmunes/metabolismo , Enfermedades Autoinmunes/patología , Western Blotting , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD4-Positivos/patología , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Mucosa Gástrica/inmunología , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patología , Gastritis/inmunología , Gastritis/patología , Humanos , Técnicas para Inmunoenzimas , Inflamación/inmunología , Inflamación/patología , Interferón gamma/metabolismo , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/patología , Metaplasia/complicaciones , Metaplasia/inmunología , Metaplasia/patología , Ratones , Ratones Endogámicos BALB C , Ratones Transgénicos , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologíaRESUMEN
The human population is currently faced with the potential use of natural or recombinant variola and monkeypox viruses as biological weapons. Furthermore, the emergence of human monkeypox in Africa and its expanding environs poses a significant natural threat. Such occurrences would require therapeutic and prophylactic intervention with antivirals to minimize morbidity and mortality of exposed populations. Two orally-bioavailable antivirals are currently in clinical trials; namely CMX001, an ether-lipid analog of cidofovir with activity at the DNA replication stage and ST-246, a novel viral egress inhibitor. Both of these drugs have previously been evaluated in the ectromelia/mousepox system; however, the trigger for intervention was not linked to a disease biomarker or a specific marker of virus replication. In this study we used lethal, intranasal, ectromelia virus infections of C57BL/6 and hairless SKH1 mice to model human disease and evaluate exanthematous rash (rash) as an indicator to initiate antiviral treatment. We show that significant protection can be provided to C57BL/6 mice by CMX001 or ST-246 when therapy is initiated on day 6 post infection or earlier. We also show that significant protection can be provided to SKH1 mice treated with CMX001 at day 3 post infection or earlier, but this is four or more days before detection of rash (ST-246 not tested). Although in this model rash could not be used as a treatment trigger, viral DNA was detected in blood by day 4 post infection and in the oropharyngeal secretions (saliva) by day 2-3 post infection - thus providing robust and specific markers of virus replication for therapy initiation. These findings are discussed in the context of current respiratory challenge animal models in use for the evaluation of poxvirus antivirals.
Asunto(s)
Benzamidas/administración & dosificación , Biomarcadores Farmacológicos/análisis , Citosina/análogos & derivados , Ectromelia Infecciosa/tratamiento farmacológico , Isoindoles/administración & dosificación , Monkeypox virus/efectos de los fármacos , Organofosfonatos/administración & dosificación , Viruela/tratamiento farmacológico , Animales , Línea Celular , Citosina/administración & dosificación , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Virus de la Ectromelia/efectos de los fármacos , Virus de la Ectromelia/fisiología , Ectromelia Infecciosa/genética , Ectromelia Infecciosa/virología , Femenino , Humanos , Ratones , Ratones Pelados , Ratones Endogámicos C57BL , Monkeypox virus/fisiología , Viruela/virología , Virus de la Viruela/efectos de los fármacos , Virus de la Viruela/genética , Virus de la Viruela/fisiología , Replicación Viral/efectos de los fármacosRESUMEN
BCL-2/E1B-19 kDa-interacting protein 3 (BNIP3) is a BH3-only mitochondrial protein. Expression of BNIP3 is strongly stimulated by hypoxia. Up-regulation of BNIP3 has been detected in several human carcinomas including carcinomas of the lung and breast. The significance of BNIP3 overexpression in these cancers is not known. To determine whether BNIP3 plays a role in tumor growth, we generated A549 lung carcinoma cells that overexpressed BNIP3 and examined their ability to form tumors in the mouse xenograft model. All cell lines that overexpressed BNIP3 formed larger tumors compared to the parental or vector-transformed A549 cells. Breast carcinoma cell lines that overexpressed BNIP3 also induced tumors in athymic mice in the absence of hormone administration, while the parental cell line did not. Stable shRNA-mediated knockdown of endogenous BNIP3 severely impaired the tumorigenic activity of A549 cells. The tumor growth-enhancing activity was reduced by deletion of the BH3 domain of BNIP3. Expression of a dominant-negative mutant of BNIP3 lacking the C-terminal transmembrane domain also inhibited the tumorigenic potential of A549 cells. These results suggest that BNIP3 plays a fundamental role in the development of certain solid tumors such as the lung and breast carcinomas.
RESUMEN
Chagas' disease, induced by Trypanosoma cruzi , is a common cause of infectious myocarditis. Recent clinical treatment trials and vaccine studies indicate that chagasic immunopathology is directed against the parasite and not self-antigens. Therefore, vaccines may have the potential to protect against disease progression. Certain combinations of mouse and parasite strains produce significant histopathology and can be used for safety analyses of new vaccination strategies. The goals of this study were to determine (1) whether the development of chagasic cardiomyopathy in the murine model could be identified by electrocardiogram (ECG); and (2) whether these potential chagasic ECG changes would correlate with histopathologic findings. Groups of BALB/c, C57BL/6, and C3H mice were infected with different parasite strains (Tulahuén, Brazil, or Sylvio-X10/4) and evaluated weekly by ECG. Selected tissues from subsets of mice were harvested periodically for blinded histologic evaluation. Significantly increased proportions of BALB/c mice infected with Brazil and Tulahuén strain parasites displayed prolonged QT intervals. Prolonged mean QT intervals detected in infected BALB/c mice significantly correlated with chagasic histopathologic changes. These results indicate that ECG can be used as a non-invasive method to screen for immune-mediated damage resulting in chagasic cardiomyopathy in the murine model.
Asunto(s)
Cardiomiopatía Chagásica/diagnóstico , Electrocardiografía , Animales , Cardiomiopatía Chagásica/patología , Modelos Animales de Enfermedad , Femenino , Inflamación/parasitología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Ratones SCID , Músculo Esquelético/patología , Miocardio/patología , Estadísticas no ParamétricasRESUMEN
Breast cancer is the leading cause of cancer death among women. We have shown previously an antiproliferative effect of MBP-1 on several human cancer cells. In this study, we have examined the potential of MBP-1 as a gene therapeutic candidate in regression of breast cancer growth and metastasis in an immunocompetent mouse model. For this, we have used a mouse breast cancer cell line (EO771) and syngeneic C57BL/6 mice. EO771 cells were implanted into the mammary fat pad of C57BL/6 mice. Replication-deficient recombinant adenovirus expressing MBP-1 was administered intratumorally to determine gene therapeutic potential. The results showed a significant regression of primary and distant (lung) tumor growth. Animals exhibited prolonged survival on treatment with MBP-1 compared with the control group (dl312). Subsequent studies suggested that MBP-1 inhibits matrix metalloproteinase expression in human breast cancer cells. Cells transduced with MBP-1 displayed inhibition of migration in a wound-healing assay. The conditioned medium from MBP-1-transduced cells blocked in vitro tube formation assay and inhibited expression of several angiogenic molecules. Taken together, our study shows that MBP-1 acts as a double-edged sword by inhibiting primary and metastatic tumor growth and modulating matrix metalloproteinase expression with a therapeutic potential against breast cancer progression.
Asunto(s)
Proteínas de Unión al ADN/biosíntesis , Neoplasias Mamarias Experimentales/terapia , Adenoviridae/genética , Animales , Neoplasias de la Mama/irrigación sanguínea , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Procesos de Crecimiento Celular/genética , Línea Celular Tumoral , Movimiento Celular/fisiología , Proteínas de Unión al ADN/genética , Células Endoteliales/patología , Terapia Genética/métodos , Humanos , Inmunocompetencia , Neoplasias Mamarias Experimentales/irrigación sanguínea , Neoplasias Mamarias Experimentales/genética , Neoplasias Mamarias Experimentales/patología , Metaloproteinasa 2 de la Matriz/biosíntesis , Metaloproteinasa 2 de la Matriz/metabolismo , Inhibidores de la Metaloproteinasa de la Matriz , Ratones , Ratones Endogámicos C57BL , Neovascularización Patológica/metabolismo , Neovascularización Patológica/patologíaRESUMEN
Suitable animal models are needed to study monkeypox virus (MPXV) as human monkeypox clinically resembles smallpox and MPXV is a zoonotic and potential bioterroristic agent. We have demonstrated that a species of African dormice, Graphiurus kelleni, is susceptible to a lethal infection of MPXV and that MPXV replicated in multiple organs of this species. Following intranasal administration, MPXV replicated locally in the nasal mucosa causing necrosis and hemorrhage with subsequent systemic spread to lymph nodes, spleen, liver, and other tissues where it caused severe necrosis and/or hemorrhage leading to death. The dormouse model was validated for testing prophylactic (Dryvax vaccine) and therapeutic (cidofovir) test articles against intranasal challenges with MPXV.