RESUMO
Human adenoviruses can cause serious, disseminated infections in immunocompromised patients. For pediatric allogeneic stem cell transplant patients, the case fatality rate can reach 80%. Still, there is no available antiviral drug that is specifically approved by the Food and Drug Administration for the treatment of adenovirus infections. To fill this pressing medical need, we have developed NPP-669, a prodrug of cidofovir with broad activity against double-stranded DNA viruses, including adenoviruses. Here, we report on the in vivo anti-adenoviral efficacy of NPP-669. Using the immunosuppressed Syrian hamster as the model, we show that NPP-669 is highly efficacious when dosed orally at 1 mg/kg and 3 mg/kg. In a delayed administration experiment, NPP-669 was more effective than brincidofovir, a similar compound that reached Phase III clinical trials. Furthermore, parenteral administration of NPP-669 increased its efficacy approximately 10-fold compared to oral dosing without apparent toxicity, suggesting that this route may be preferable in a hospital setting. Based on these findings, we believe that NPP-669 is a promising new compound that needs to be further investigated.
Assuntos
Antivirais , Cidofovir , Citosina , Mesocricetus , Organofosfonatos , Pró-Fármacos , Animais , Antivirais/farmacologia , Antivirais/uso terapêutico , Pró-Fármacos/farmacologia , Pró-Fármacos/uso terapêutico , Humanos , Cidofovir/farmacologia , Cidofovir/uso terapêutico , Organofosfonatos/farmacologia , Organofosfonatos/uso terapêutico , Citosina/análogos & derivados , Citosina/farmacologia , Citosina/uso terapêutico , Adenovírus Humanos/efeitos dos fármacos , Infecções por Adenovirus Humanos/tratamento farmacológico , Infecções por Adenovirus Humanos/virologia , Modelos Animais de Doenças , Cricetinae , Administração OralRESUMO
DNA viruses are responsible for many diseases in humans. Current treatments are often limited by toxicity, as in the case of cidofovir (CDV, Vistide), a compound used against cytomegalovirus (CMV) and adenovirus (AdV) infections. CDV is a polar molecule with poor bioavailability, and its overall clinical utility is limited by the high occurrence of acute nephrotoxicity. To circumvent these disadvantages, we designed nine CDV prodrug analogues. The prodrugs modulate the polarity of CDV with a long sulfonyl alkyl chain attached to one of the phosphono oxygens. We added capping groups to the end of the alkyl chain to minimize ß-oxidation and focus the metabolism on the phosphoester hydrolysis, thereby tuning the rate of this reaction by altering the alkyl chain length. With these modifications, the prodrugs have excellent aqueous solubility, optimized metabolic stability, increased cellular permeability, and rapid intracellular conversion to the pharmacologically active diphosphate form (CDV-PP). The prodrugs exhibited significantly enhanced antiviral potency against a wide range of DNA viruses in infected human foreskin fibroblasts. Single-dose intravenous and oral pharmacokinetic experiments showed that the compounds maintained plasma and target tissue levels of CDV well above the EC50 for 24 h. These experiments identified a novel lead candidate, NPP-669. NPP-669 demonstrated efficacy against CMV infections in mice and AdV infections in hamsters following oral (p.o.) dosing at a dose of 1 mg/kg BID and 0.1 mg/kg QD, respectively. We further showed that NPP-669 at 30 mg/kg QD did not exhibit histological signs of toxicity in mice or hamsters. These data suggest that NPP-669 is a promising lead candidate for a broad-spectrum antiviral compound.
Assuntos
Infecções por Citomegalovirus , Organofosfonatos , Pró-Fármacos , Camundongos , Humanos , Animais , Antivirais/farmacocinética , Disponibilidade Biológica , Pró-Fármacos/farmacologia , Citosina , CidofovirRESUMO
AIMS AND OBJECTIVES: Our objective was to rapidly adapt and scale a registered nurse-driven Coordinated Transitional Care (C-TraC) programme to provide intensive home monitoring and optimise care for outpatient Veterans with COVID-19 in a large urban Unites States healthcare system. BACKGROUND: Our diffuse primary care network had no existing model of care by which to provide coordinated result tracking and monitoring of outpatients with COVID-19. DESIGN: Quality improvement implementation project. METHODS: We used the Replicating Effective Programs model to guide implementation, iterative Plan-Do-Study-Act cycles and SQUIRE reporting guidelines. Two transitional care registered nurses, and a geriatrician medical director developed a protocol that included detailed initial assessment, overnight delivery of monitoring equipment and phone-based follow-up tailored to risk level and symptom severity. We tripled programme capacity in time for the surge of cases by training Primary Care registered nurses. RESULTS: Between 23 March and 15 May 2020, 120 Veterans with COVID-19 were enrolled for outpatient monitoring; over one-third were aged 65 years or older, and 70% had medical conditions associated with poor COVID-19 outcomes. All Veterans received an initial call within a few hours of the laboratory reporting positive results. The mean length of follow-up was 8.1 days, with an average of 4.2 nurse and 1.3 physician or advanced practice clinician contacts per patient. The majority (85%) were managed entirely in the outpatient setting. After the surge, the model was disseminated to individual primary care teams through educational sessions. CONCLUSION: A model based on experienced registered nurses can provide comprehensive, effective and sustainable outpatient monitoring to high-risk populations with COVID-19.
Assuntos
COVID-19 , Cuidado Transicional , Humanos , Pacientes Ambulatoriais , Melhoria de Qualidade , SARS-CoV-2RESUMO
Human adenovirus (HAdV) infection is common in the general population and can cause a range of clinical manifestations, among which pneumonia and keratoconjunctivitis are the most common. Although HAdV infections are mostly self-limiting, infections in immunocompromised individuals can be severe. No antiviral drug has been approved for treating adenoviruses. Filociclovir (FCV) is a nucleoside analogue which has successfully completed phase I human clinical safety studies and is now being developed for treatment of human cytomegalovirus (HCMV)-related disease in immunocompromised patients. In this report, we show that FCV is a potent broad-spectrum inhibitor of HAdV types 4 to 8, with 50% effective concentrations (EC50s) ranging between 1.24 and 3.6 µM and a 50% cytotoxic concentration (CC50) of 100 to 150 µM in human foreskin fibroblasts (HFFs). We also show that the prophylactic oral administration of FCV (10 mg/kg of body weight) 1 day prior to virus challenge and then daily for 14 days to immunosuppressed Syrian hamsters infected intravenously with HAdV6 was sufficient to prevent morbidity and mortality. FCV also mitigated tissue damage and inhibited virus replication in the liver. The 10-mg/kg dose had similar effects even when the treatment was started on day 4 after virus challenge. Furthermore, FCV administered at the same dose after intranasal challenge with HAdV6 partially mitigated body weight loss but significantly reduced pathology and virus replication in the lung. These findings suggest that FCV could potentially be developed as a pan-adenoviral inhibitor.
Assuntos
Infecções por Adenovirus Humanos , Adenovírus Humanos , Infecções por Citomegalovirus , Infecções por Adenovirus Humanos/tratamento farmacológico , Animais , Antivirais/farmacologia , Antivirais/uso terapêutico , Cricetinae , Infecções por Citomegalovirus/tratamento farmacológico , Humanos , Replicação ViralRESUMO
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.
Assuntos
Infecções por Adenovirus Humanos/patologia , Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/patogenicidade , Fígado/virologia , Carga Viral , Replicação Viral , Adenovírus Humanos/classificação , Adenovírus Humanos/fisiologia , Animais , Linhagem Celular , Cricetinae , Modelos Animais de Doenças , Humanos , Rim/virologia , Células de Kupffer/virologia , Fígado/patologia , Pulmão/virologia , Macrófagos/virologia , MesocricetusRESUMO
[This corrects the article DOI: 10.1371/journal.ppat.1005084.].
RESUMO
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.
Assuntos
Infecções por Adenoviridae/imunologia , Adenovírus Humanos/patogenicidade , Modelos Animais de Doenças , Interferon Tipo I/imunologia , Fator de Transcrição STAT2/deficiência , Infecções por Adenoviridae/patologia , Adenovírus Humanos/imunologia , Animais , Animais Geneticamente Modificados , Linhagem Celular Tumoral , Cricetinae , Citometria de Fluxo , Técnicas de Inativação de Genes , Humanos , Mesocricetus , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT2/imunologiaRESUMO
Adenovirus infections of immunocompromised patients can develop into deadly multiorgan or systemic disease. The virus is especially threatening for pediatric allogeneic hematopoietic stem cell transplant recipients; according to some studies, 10% or more of these patients succumb to disease resulting from adenovirus infection. At present, there is no drug approved for the treatment or prevention of adenovirus infections. Compounds that are approved to treat other virus infections are used off-label to combat adenovirus, but only anecdotal evidence of the efficacy of these drugs exists. Ganciclovir, a drug approved for the treatment of herpesvirus infection, was previously reported to be effective against human adenoviruses in vitro. To model adenovirus infections in immunocompromised humans, we examined ganciclovir's efficacy in immunosuppressed Syrian hamsters intravenously infected with type 5 human adenovirus (Ad5). This animal model is permissive for Ad5 replication, and the animals develop symptoms similar to those seen in humans. We demonstrate that ganciclovir suppresses Ad5 replication in the liver of infected hamsters and that it mitigates the consequences of Ad5 infections in these animals when administered prophylactically or therapeutically. We show that ganciclovir inhibits Ad5 DNA synthesis and late gene expression. The mechanism of action for the drug is not clear; preliminary data suggest that it exerts its antiadenoviral effect by directly inhibiting the adenoviral DNA polymerase. While more extensive studies are required, we believe that ganciclovir is a promising drug candidate to treat adenovirus infections. Brincidofovir, a drug with proven activity against Ad5, was used as a positive control in the prophylactic experiment.
Assuntos
Infecções por Adenoviridae/tratamento farmacológico , Adenovírus Humanos/efeitos dos fármacos , Antivirais/farmacologia , Ganciclovir/farmacologia , Hospedeiro Imunocomprometido , Proteínas Virais/antagonistas & inibidores , Infecções por Adenoviridae/imunologia , Infecções por Adenoviridae/mortalidade , Infecções por Adenoviridae/virologia , Adenovírus Humanos/genética , Adenovírus Humanos/crescimento & desenvolvimento , Adenovírus Humanos/patogenicidade , Animais , Peso Corporal/efeitos dos fármacos , Linhagem Celular Tumoral , Citosina/análogos & derivados , Citosina/farmacologia , DNA Polimerase Dirigida por DNA/genética , DNA Polimerase Dirigida por DNA/metabolismo , Feminino , Expressão Gênica , Humanos , Masculino , Mesocricetus , Organofosfonatos/farmacologia , Análise de Sobrevida , Transaminases/sangue , Carga Viral/efeitos dos fármacos , Proteínas Virais/genética , Proteínas Virais/metabolismo , Replicação Viral/efeitos dos fármacosRESUMO
Adenovirus infections of immunocompromised humans are a significant source of morbidity and mortality. Presently, there is no drug specifically approved for the treatment of adenovirus infections by the FDA. The state-of-the-art treatment of such infections is the off-label use of cidofovir, an acyclic nucleotide phosphonate. While cidofovir inhibits adenovirus replication, it has dose-limiting kidney toxicity. There is an apparent need for a better compound to treat adenovirus infections. To this end, we have been developing acyclic nucleotide phosphonate prodrugs that utilize an amino acid scaffold equipped with a lipophilic modifier. Here, we compare the antiviral potential of two prodrugs of HPMPA that differ only in the amino acid-based promoiety: USC-087, based on an N-hexadecyl tyrosinamide, and USC-093, based on an N-hexadecyl serinamide. Oral administration of both compounds was very efficacious against disseminated HAdV-C6 infection in immunosuppressed Syrian hamsters, suppressing virus replication and mitigating pathology even when treatment was withheld until 4 days after challenge. We saw only marginal efficacy after respiratory infection of hamsters, which may reflect suboptimal distribution to the lung. Importantly, neither compound induced intestinal toxicity, which was observed as the major adverse effect in clinical trials of brincidofovir, a prodrug of cidofovir which also contains a C-16 modifier. Notably, we found that there was a significant difference in the nephrotoxicity of the two compounds: USC-087 caused significant kidney toxicity while USC-093 did not, at effective doses. These findings will be valuable guidepoints in the future evolution of this new class of potential prodrugs to treat adenovirus infections.
Assuntos
Adenina/análogos & derivados , Infecções por Adenoviridae , Infecções por Adenovirus Humanos , Organofosfonatos , Pró-Fármacos , Tirosina/análogos & derivados , Cricetinae , Animais , Humanos , Infecções por Adenovirus Humanos/tratamento farmacológico , Cidofovir/farmacologia , Cidofovir/uso terapêutico , Mesocricetus , Antivirais/uso terapêutico , Pró-Fármacos/farmacologia , Pró-Fármacos/uso terapêutico , Adenoviridae , Replicação Viral , Organofosfonatos/farmacologia , Organofosfonatos/uso terapêutico , Infecções por Adenoviridae/tratamento farmacológico , Citosina/farmacologia , Citosina/uso terapêutico , Aminoácidos/farmacologia , Nucleotídeos/uso terapêuticoRESUMO
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.
Assuntos
Citosina/análogos & derivados , Imunossupressores/uso terapêutico , Organofosfonatos/farmacologia , Adenoviridae/metabolismo , Infecções por Adenoviridae/metabolismo , Infecções por Adenoviridae/terapia , Animais , Antivirais/farmacologia , Cricetinae , Citosina/farmacologia , Modelos Animais de Doenças , Ensaios de Seleção de Medicamentos Antitumorais , Células-Tronco Hematopoéticas/citologia , Humanos , Fígado/metabolismo , Mesocricetus , Modelos BiológicosRESUMO
Immune responses against adenovirus (Ad) vectors pose a possible concern for the outcome of treatment efficacy. To address the role of preexisting immunity in oncolytic Ad vector antitumor efficacy following intratumoral injection of vector as well as tumor-to-tissue spread of the vector, we employed the Syrian hamster model. These animals are immunocompetent, and their tumors and tissues are permissive for replication of Ad type 5 (Ad5). We used the adenovirus death protein-overexpressing Ad5-based vector INGN 007. Subcutaneous tumors were established in groups of hamsters that were or were not immunized with Ad5. Half of the hamsters in these groups were immunosuppressed with cyclophosphamide. For all groups, tumors injected with INGN 007 grew significantly more slowly than those injected with buffer. Under immunocompetent conditions, there was no significant effect of preexisting immunity on vector antitumor efficacy. Soon after the tumors in naïve animals were injected with vector, the hamsters developed neutralizing antibody (NAb) and the difference in NAb titers between the naïve and immunized groups diminished. Under immunosuppressed conditions, preexisting NAb did significantly reduce vector efficacy. Thus, NAb do reduce vector efficacy to some extent, but immunosuppression is required to observe the effect. Regarding vector toxicity, there was spillover of vector from the tumor to the liver and lungs in naïve immunocompetent hamsters, and this was nearly eliminated in the immunized hamsters. Thus, preexisting immunity to Ad5 does not affect INGN 007 antitumor efficacy following intratumoral injection, but immunity prevents vector spillover from the tumor to the liver and lungs.
Assuntos
Vetores Genéticos/uso terapêutico , Neoplasias Experimentais/terapia , Terapia Viral Oncolítica , Vírus Oncolíticos/imunologia , Adenoviridae/genética , Adenoviridae/imunologia , Animais , Anticorpos Antivirais/imunologia , Linhagem Celular Tumoral , Cricetinae , Ciclofosfamida/farmacologia , Humanos , Imunocompetência , Terapia de Imunossupressão , Fígado/virologia , Pulmão/virologia , Mesocricetus , Modelos Animais , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/virologia , Replicação ViralRESUMO
We have used Syrian hamsters to examine the role of pre-existing immunity to adenovirus (Ad) 5 in the toxicity of the oncolytic Ad vector INGN 007. Groups of hamsters were or were not immunized with Ad5. Half the hamsters were immunosuppressed using cyclophosphamide (CP), then injected intravenously (i.v.) with 3x the maximum tolerated dose (MTD) of INGN 007 (in immunocompetent hamsters), and toxicity and vector replication in the liver were quantitated. In nonimmunized immunocompetent hamsters, toxicity was observed early but the hamsters recovered by day 6 after vector injection. In nonimmunized immunosuppressed hamsters, the vector was lethal by 3 days. Pre-existing neutralizing antibody (NAb) prevented liver infection and hepatotoxicity in both immunocompetent and immunosuppressed hamsters. In another study, passive immunization of immunosuppressed hamsters 1 day before a lethal dose (1x MTD) of INGN 007 prevented liver infection and replication, but immunization 1 day after vector administration was barely effective. When immunosuppressed hamsters were passively immunized 1 day after injection of 1/3rd the MTD of INGN 007, then significant protection was observed against liver infection and toxicity. Therefore, serum NAb are sufficient to prevent oncolytic Ad vector liver infection and toxicity. We saw no evidence that pre-existing immunity was associated with increased vector toxicity.
Assuntos
Adenoviridae/imunologia , Vetores Genéticos/imunologia , Vetores Genéticos/toxicidade , Imunidade/fisiologia , Animais , Anticorpos Neutralizantes/imunologia , Cricetinae , Ciclofosfamida/farmacologia , Feminino , Imunidade/efeitos dos fármacos , Imunossupressores/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Mesocricetus , Terapia Viral Oncolítica/efeitos adversos , Terapia Viral Oncolítica/métodosRESUMO
BACKGROUND: Early electronic identification of patients at the highest risk for heart failure (HF) readmission presents a challenge. Data needed to identify HF patients are in a variety of areas in the electronic medical record (EMR) and in different formats. OBJECTIVE: The purpose of this paper is to describe the development and data validation of a HF dashboard that monitors the overall metrics of outcomes and treatments of the veteran patient population with HF and enhancing the use of guideline-directed pharmacologic therapies. METHODS: We constructed a dashboard that included several data points: care assessment need score; ejection fraction (EF); medication concordance; laboratory tests; history of HF; and specified comorbidities based on International Classification of Disease (ICD), ninth and tenth codes. Data validation testing with user test scripts was utilized to ensure output accuracy of the dashboard. Nine providers and key senior management participated in data validation. RESULTS: A total of 43 medical records were reviewed and 66 HF dashboard data discrepancies were identified during development. Discrepancies identified included: generation of multiple EF values on a few patients, missing or incorrect ICD codes, laboratory omission, incorrect medication issue dates, patients incorrectly noted as nonconcordant for medications, and incorrect dates of last cardiology appointments. Continuous integration and builds identified defects-an important process of the verification and validation of biomedical software. Data validation and technical limitations are some challenges that were encountered during dashboard development. Evaluations by testers and their focused feedback contributed to the lessons learned from the challenges. CONCLUSION: Continuous refinement with input from multiple levels of stakeholders is crucial to development of clinically useful dashboards. Extraction of all relevant information from EMRs, including the use of natural language processing, is crucial to development of dashboards that will help improve care of individual patients and populations.
Assuntos
Registros Eletrônicos de Saúde , Insuficiência Cardíaca/tratamento farmacológico , Qualidade da Assistência à Saúde , Interface Usuário-Computador , Veteranos , Humanos , Reprodutibilidade dos TestesRESUMO
Model animals are indispensable for the study of human diseases, and in general, of complex biological processes. The Syrian hamster is an important model animal for infectious diseases, behavioral science and metabolic science, for which more experimental tools are becoming available. Here, we describe the generation and characterization of an interleukin-2 receptor subunit gamma (Il2rg) knockout (KO) Syrian hamster strain. In humans, mutations in IL2RG can result in a total failure of T and natural killer (NK) lymphocyte development and nonfunctional B lymphocytes (X-linked severe combined immunodeficiency; XSCID). Therefore, we sought to develop a non-murine model to study XSCID and the infectious diseases associated with IL2RG deficiency. We demonstrated that the Il2rg KO hamsters have a lymphoid compartment that is greatly reduced in size and diversity, and is impaired in function. As a result of the defective adaptive immune response, Il2rg KO hamsters developed a more severe human adenovirus infection and cleared virus less efficiently than immune competent wild-type hamsters. Because of this enhanced virus replication, Il2rg KO hamsters developed more severe adenovirus-induced liver pathology than wild-type hamsters. This novel hamster strain will provide researchers with a new tool to investigate human XSCID and its related infections.
Assuntos
Imunidade Adaptativa , Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/patogenicidade , Hospedeiro Imunocomprometido , Subunidade gama Comum de Receptores de Interleucina/genética , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/genética , Células A549 , Infecções por Adenovirus Humanos/genética , Infecções por Adenovirus Humanos/imunologia , Infecções por Adenovirus Humanos/metabolismo , Adenovírus Humanos/crescimento & desenvolvimento , Animais , Animais Geneticamente Modificados , Modelos Animais de Doenças , Feminino , Técnicas de Inativação de Genes , Células HEK293 , Interações Hospedeiro-Patógeno , Humanos , Subunidade gama Comum de Receptores de Interleucina/deficiência , Fígado/imunologia , Fígado/metabolismo , Fígado/virologia , Linfócitos/imunologia , Linfócitos/metabolismo , Linfócitos/virologia , Masculino , Mesocricetus/genética , Carga Viral , Replicação Viral , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/imunologia , Doenças por Imunodeficiência Combinada Ligada ao Cromossomo X/metabolismoRESUMO
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.
Assuntos
Adenoviridae/genética , Neoplasias Experimentais/terapia , Terapia Viral Oncolítica , Replicação Viral/imunologia , Adenoviridae/imunologia , Adenoviridae/fisiologia , Animais , Antineoplásicos/uso terapêutico , Divisão Celular , Cricetinae , Ciclofosfamida/uso terapêutico , Imuno-Histoquímica , Mesocricetus , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/patologia , Testes de NeutralizaçãoRESUMO
The symptoms of human adenovirus infections are generally mild and self-limiting. However, these infections have been gaining importance in recent years because of a growing number of immunocompromised patients. Solid organ and hematopoietic stem cell transplant patients are subjected to severe immunosuppressive regimes and cannot efficaciously eliminate virus infections. In these patients, adenovirus infections can develop into deadly multi-organ disseminated disease. Presently, in the absence of approved therapies, physicians rely on drugs developed for other purposes to treat adenovirus infections. As there is a need for anti-adenoviral therapies, researchers have been developing new agents and repurposing existing ones to treat adenovirus infections. There are several small molecule drugs that are being tested for their efficacy against human adenoviruses; some of these have reached clinical trials, while others are still in the preclinical phase. Besides these compounds, research on immunotherapy against adenoviral infection has made significant progress, promising another modality for treatment. The availability of an animal model confirmed the activity of some drugs already in clinical use while proving that others are inactive. This led to the identification of several lead compounds that await further development. In the present article, we review the current status of anti-adenoviral therapies and their advancement by in vivo studies in the Syrian hamster model.
Assuntos
Infecções por Adenoviridae/tratamento farmacológico , Adenovírus Humanos/efeitos dos fármacos , Antivirais/farmacologia , Antivirais/uso terapêutico , Desenvolvimento de Medicamentos , Mesocricetus , Animais , Cricetinae , Modelos Animais de DoençasRESUMO
BACKGROUND: Poor medication adherence is a significant problem in hypertensive African Americans. Although motivational interviewing (MINT) is effective for adoption and maintenance of health behaviors in patients with chronic diseases, its effect on medication adherence remains untested in this population. METHODS: This randomized controlled trial tested the effect of a practice-based MINT counseling vs. usual care (UC) on medication adherence and blood pressure (BP) in 190 hypertensive African Americans (88% women; mean age 54 years). Patients were recruited from two community-based primary care practices in New York City. The primary outcome was adherence measured by electronic pill monitors; the secondary outcome was within-patient change in office BP from baseline to 12 months. RESULTS: Baseline adherence was similar in both groups (56.2 and 56.6% for MINT and UC, respectively, P = 0.94). Based on intent-to-treat analysis using mixed-effects regression, a significant time x group interaction with model-predicted posttreatment adherence rates of 43 and 57% were found in the UC and MINT groups, respectively (P = 0.027), with a between-group difference of 14% (95% confidence interval, -0.2 to -27%). The between-group difference in systolic and diastolic BP was -6.1 mm Hg (P = 0.065) and -1.4 mm Hg (P = 0.465), respectively, in favor of the MINT group. CONCLUSIONS: A practice-based MINT counseling led to steady maintenance of medication adherence over time, compared to significant decline in adherence for UC patients. This effect was associated with a modest, nonsignificant trend toward a net reduction in systolic BP in favor of the MINT group.
Assuntos
Anti-Hipertensivos/uso terapêutico , Negro ou Afro-Americano , Hipertensão/tratamento farmacológico , Hipertensão/etnologia , Adesão à Medicação/etnologia , Pressão Sanguínea/fisiologia , Feminino , Seguimentos , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Cidade de Nova Iorque/epidemiologia , Resultado do TratamentoRESUMO
Novel approaches are needed to improve the antitumor potency and to increase the cancer specificity of oncolytic adenoviruses (Ad). We hypothesized that the combination of interferon-alpha (IFN-α) expression with a specific mutation in the e1a gene of Ad could target vector replication to genetic defects in the IFN-α pathway resulting in both improved antitumor efficacy and reduced toxicity. The conditionally replicative Ad vector KD3-IFN carries the dl1101/1107 mutation in the e1a gene that eliminates binding of E1A proteins to p300/CBP and pRb. KD3-IFN expresses human IFN-α in concurrence with vector replication and overexpresses the adenovirus death protein (ADP; E3-11.6K). The antitumor activity of KD3-IFN was significantly higher than that of a control vector in established human hepatocellular carcinoma tumors in immunodeficient mice and in hamster kidney cancer tumors in immunocompetent Syrian hamsters. The dl1101/1107 mutation rendered Ad replication sensitive to the antiviral effect of IFN-α in normal as opposed to cancer cells. These results translated to reduced vector toxicity upon systemic administration to C57BL/6 mice. The combination of Ad oncolysis, ADP overexpression, and IFN-α-mediated immunotherapy represents a three-pronged approach for increasing the anticancer efficacy of replicative Ads. Exploiting the dl1101/1107 mutation provides a mechanism for additional selectivity of IFN-α-expressing replication-competent Ads.
RESUMO
Novel approaches are needed to improve the antitumor potency and to increase the cancer specificity of oncolytic adenoviruses (Ad). We hypothesized that the combination of interferon-alpha (IFN-alpha) expression with a specific mutation in the e1a gene of Ad could target vector replication to genetic defects in the IFN-alpha pathway resulting in both improved antitumor efficacy and reduced toxicity. The conditionally replicative Ad vector KD3-IFN carries the dl1101/1107 mutation in the e1a gene that eliminates binding of E1A proteins to p300/CBP and pRb. KD3-IFN expresses human IFN-alpha in concurrence with vector replication and overexpresses the adenovirus death protein (ADP; E3-11.6K). The antitumor activity of KD3-IFN was significantly higher than that of a control vector in established human hepatocellular carcinoma tumors in immunodeficient mice and in hamster kidney cancer tumors in immunocompetent Syrian hamsters. The dl1101/1107 mutation rendered Ad replication sensitive to the antiviral effect of IFN-alpha in normal as opposed to cancer cells. These results translated to reduced vector toxicity upon systemic administration to C57BL/6 mice. The combination of Ad oncolysis, ADP overexpression, and IFN-alpha-mediated immunotherapy represents a three-pronged approach for increasing the anticancer efficacy of replicative Ads. Exploiting the dl1101/1107 mutation provides a mechanism for additional selectivity of IFN-alpha-expressing replication-competent Ads.
Assuntos
Adenoviridae/genética , Proteínas E1A de Adenovirus/metabolismo , Interferon-alfa/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Vírus Oncolíticos/genética , Proteínas E1A de Adenovirus/genética , Animais , Linhagem Celular , Sobrevivência Celular , Cricetinae , Feminino , Expressão Gênica , Terapia Genética , Vetores Genéticos/genética , Genoma Viral/genética , Interferon-alfa/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/terapia , Camundongos , Camundongos Nus , Mutação/genética , Taxa de Sobrevida , Fatores de Tempo , Transgenes/genética , Replicação Viral , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJECTIVE: In many developing countries, access to medical imaging is limited by availability of resources. Portable ultrasound shows great promise to meet the needs in these countries because it is transportable and relatively inexpensive, and it has a wide range of applications. As part of the Ghana Health Mission, Sekondi-Takoradi, Ghana, we explored the utility of ultrasound in primary care and hospital settings during March 2004. Our objective was to evaluate the clinical utility of a portable ultrasound machine in a variety of physical conditions and multiple clinical scenarios. METHODS: Ultrasound examinations were performed at 2 primary care sites and 2 hospitals using a portable ultrasound machine with linear and curved linear phased array transducers. Most ultrasound examinations were musculoskeletal, with the remainder being obstetric, pelvic, breast, vascular, abdominal, and genitourinary examinations. RESULTS: In clinic settings, musculoskeletal ultrasound represented 46% (16) of the ultrasound examinations performed, and 29% (10) of the cases were a combination of abdominal, pelvic, and genitourinary examinations. In hospital settings, abdominal, pelvic, and genitourinary ultrasound examinations combined were 56% (18), and musculoskeletal was 41% (13). Of the 67 ultrasound examinations performed, 81% (54) showed abnormal findings, 81% (54) were considered to add to the clinical diagnosis, and 40% (27) influenced medical care for the patients. CONCLUSIONS: This experience shows the usefulness of portable ultrasound examinations performed by a skilled radiologist in a clinical setting in Ghana; the challenge is to address how to best incorporate ultrasound into the current practice of medical professionals in developing countries.