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We elucidate the role of p21/Waf-1, a cyclin-dependent kinase inhibitor, on the oncolytic infection and replication cycle of adenovirus by studying both mRNA and adenoviral proteins expression. We found that infection in the absen...
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We elucidate the role of p21/Waf-1, a cyclin-dependent kinase inhibitor, on the oncolytic infection and replication cycle of adenovirus by studying both mRNA and adenoviral proteins expression. We found that infection in the absence of p21 causes a significant increase in adenoviral genomes and late gene expression. Similarly, the oncolytic adenoviral infected p21 ?/? cells have earlier formation of replication foci and robust replication kinetics that were not observed in the wild type p21/Waf-1 intact cells. These findings suggest a culmination that the presence of intact p21 in host cells causes defects in the oncolytic viral life cycle which results in the production of immature and noninfectious particles.
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Conditionally-replicating adenoviruses (CRAds) and other oncolytic viruses replicate selectively in tumor cells, presenting a potential cancer treatment approach. To optimize application of these viruses, understanding of early sp...
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Conditionally-replicating adenoviruses (CRAds) and other oncolytic viruses replicate selectively in tumor cells, presenting a potential cancer treatment approach. To optimize application of these viruses, understanding of early spread of these viruses in target cells is important. Here we used a recombinant adenovirus expressing enhanced jellyfish green fluorescent protein (EGFP) in place of the EIA and EIB genes (AdEGFPuci). Infection of susceptible cells (AD-293) under plaque formation conditions (MOI < < 1) on gridded culture dishes and daily monitoring allowed visualization of initially infected cells, as well as spread to neighboring cells. We determined key parameters of early infection, including the rate and efficiency of spread from the initially infected cell to other cells. It was noteworthy that a minority of initially infected cells ultimately resulted in plaques. The approaches elucidated here will be useful for determining early infection parameters for CRAds of therapeutic interest.
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A challenge to develop adenovirus (Ad)-mediated therapeutics has been issued to treat metastatic cancer via systemic administration. For effective gene therapeutics against primary and metastatic lesions, a systemically injectable...
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A challenge to develop adenovirus (Ad)-mediated therapeutics has been issued to treat metastatic cancer via systemic administration. For effective gene therapeutics against primary and metastatic lesions, a systemically injectable tumor-targeting Ad vector system must be developed. Systemic delivery of Ad, however, is hampered by immune response against Ad, short half-life in the circulation, liver uptake, and low accumulation at target disease sites. Modification of the Ad surface allows Ad to circulate in the bloodstream for a longer time, to be not targeted to the liver, and to passively accumulate in tumor sites via enhanced permeation and retention effects. The addition of affinity tags results in active targeting and high efficacy. Strategies including addition of polymer complexes, chemical modifications, and targeting moieties have been applied to develop systemically injectable Ad gene therapeutic carriers. More versatile designs of Ad hybrid complexes have been developed with inorganic nanoparticles, polymers, and lipids, making smart nanomedicine possible. Integration of viral and nonviral nanomaterials can substantially synergize both fields, creating a new concept of gene therapeutics. Here, we describe the various Ad hybrid complex systems used to overcome the limited clinical applicability of conventional Ads and enable effective treatment of distant metastatic tumors via systemic injection.
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Competing roles of coevolution, selective pressure and recombination are an emerging interest in virus evolution. We report a novel aviadenovirus from captive red-bellied parrots (Poicephalus rufiventris) that uncovers evidence of...
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Competing roles of coevolution, selective pressure and recombination are an emerging interest in virus evolution. We report a novel aviadenovirus from captive red-bellied parrots (Poicephalus rufiventris) that uncovers evidence of deep recombination among aviadenoviruses. The sequence identity of the virus was most closely related to Turkey adenovirus D (42% similarity) and other adenoviruses in chickens, turkeys and pigeons. Sequencing and comparative analysis showed that the genome comprised 40,930 nucleotides containing 42 predicted open reading frames (ORFs) 19 of which had strong similarity with genes from other adenovirus species. The new genome unveiled a lineage that likely participated in deep recombination events across the genus Aviadenovirus accounting for an ancient evolutionary relationship. We hypothesize frequent host switch events and recombination among adenovirus progenitors in Galloanserae hosts caused the radiation of extant aviadenoviruses and the newly assembled Poicephalus adenovirus genome points to a potentially broader host range of these viruses among birds.
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Adenoviral vectors have yielded promising results as carriers for gene transfer and vaccines in basic research and clinical applications. However, most common procedures to construct adenoviral vectors and manipulate adenovirus (A...
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Adenoviral vectors have yielded promising results as carriers for gene transfer and vaccines in basic research and clinical applications. However, most common procedures to construct adenoviral vectors and manipulate adenovirus (Ad) genomes are complex and labor-intensive. An easy and detailed protocol for the rapid, efficient, and modular generation of chimpanzee Ad serotype 68 (AdC68) as a molecular clone via isothermal assembly, which directionally assembles multiple DNA fragments in a single isothermal reaction without restriction enzymes or ligases, is presented. Any serotype of adenovirus with the sequence of genome known can be constructed as a molecular clone by this method. Recombinant adenoviral vectors can be created via one-step isothermal assembly in <3 days, and recombinant Ads can be rescued within 8 days. This protocol is practical for manipulations of Ad genomes, because an entire Ad genome can be divided into specific fragments within modular plasmids. In recent decades, vectors derived from adenoviruses (Ads) have been proven useful for vaccine development, gene therapy, and oncolytic virotherapy, as well as for basic biology research (Breyer et al., 2001; Zhang et al., 2011; Kaufmann and Nettelbeck, 2012).
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Cell culture based assays used to detect waterborne viruses typically call for incubating the sample for at least two weeks in order to ensure that all the culturable virus present is detected. Historically, this estimate was base...
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Cell culture based assays used to detect waterborne viruses typically call for incubating the sample for at least two weeks in order to ensure that all the culturable virus present is detected. Historically, this estimate was based, at least in part, on the length of time used for detecting poliovirus. In this study, we have examined A549 cells infected with human adenovirus type 2, and have found that a three week incubation of virus infected cells results in a higher number of detected viruses by quantal assay than what is seen after two weeks of incubation, with an average 955% increase in Most Probable Number (MPN) from 2 weeks to 3 weeks. This increase suggests that the extended incubation time is essential for accurately estimating viral titer, particularly for slow-growing viruses, UV treated samples, or samples with low titers of virus. In addition, we found that for some UV-treated samples, there was no detectable MPN at 2 weeks, but after 3 weeks, MPN values were obtained. For UV-treated samples, the average increase in MPN from 2 weeks to 3 weeks was 1401%, while untreated samples averaged a change in MPN of 674%, leading us to believe that the UV-damaged viral DNA may be able to be repaired such that viral replication then occurs. Published by Elsevier B.V.
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We reviewed case records from the California Animal Health and Food Safety (CAHFS) laboratory and the California Department of Fish and Wildlife (CDFW) spanning 25 years (1990-2014) for all deer accessions submitted to CAHFS for p...
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We reviewed case records from the California Animal Health and Food Safety (CAHFS) laboratory and the California Department of Fish and Wildlife (CDFW) spanning 25 years (1990-2014) for all deer accessions submitted to CAHFS for pathology and/or histopathology, with and without a diagnosis of adenoviral hemorrhagic disease (AHD), in order to determine the prevalence of AHD in California. We also examined spatial and temporal distribution, age, and mule deer subspecies in deer that died from AHD. Of 483 deer submitted to CAHFS for diagnostic testing in 1990-2014, 17.2% were diagnosed with confirmed AHD, and 26.5% were confirmed plus suspected cases of AHD. Columbian black-tailed deer (Odocoileus hemionus columbianus), particularly fawns and juveniles, were most frequently affected. Deer adenovirus (Odocoileus adenovirus 1; OdAdV-1) was detected by immunohistochemistry in archived CDFW formalin-fixed, paraffin-embedded tissues from deer that died in mortality events in 1981, 1983, and 1986-1987. OdAdV-1 is a common cause of hemorrhagic disease mortality events in California deer, and mortality as a result of AHD is documented as early as 1981.
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The most important factors leading to fat accumulation in children are genetic inheritance, endocrine alterations, and behavioural/environmental causes. In addition, experimental animal studies have shown that infections due to va...
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The most important factors leading to fat accumulation in children are genetic inheritance, endocrine alterations, and behavioural/environmental causes. In addition, experimental animal studies have shown that infections due to various pathogens can lead to overweight and obesity conditions, and studies of humans have found that the incidence of seroconversion against some of these may be significantly more frequent in obese adults and children than in normal subjects. However, the results of these studies are not conclusive and, in some cases, have raised more questions than answers. We reviewed the literature concerning the role of adenovirus 36 (AD-36), the most widely studied infectious agent in animals and humans, because of its potential association with childhood obesity. The available evidence suggests that more studies are needed to evaluate whether or not the association between the presence of AD-36 antibodies and obesity is simply unrelated, and to verify whether there are subjects that have greater tendency to become obese because more easily susceptible to AD-36 infection or with a predisposition to suffer from persistent viral infection more easily leading to the development of obesity. If it is demonstrated that AD-36 does play a role in obesity, it will be important to investigate possible vaccines against the infection itself or antiviral drugs capable of inhibiting disease progression.
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Introduction: Malaria remains a major threat to endemic populations and travelers, including military personnel to these areas. A malaria vaccine is feasible, as radiation attenuated sporozoites induce nearly 100% efficacy.Areas c...
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Introduction: Malaria remains a major threat to endemic populations and travelers, including military personnel to these areas. A malaria vaccine is feasible, as radiation attenuated sporozoites induce nearly 100% efficacy.Areas covered: This review covers current malaria clinical trials using adenoviruses and pre-clinical research. Heterologous prime-boost regimens, including replication-deficient human adenovirus 5 (HuAd5) carrying malaria antigens, are efficacious. However, efficacy appears to be adversely affected by pre-existing anti-HuAd5 antibodies. Current strategies focus on replacing HuAd5 with rarer human adenoviruses or adenoviruses isolated from non-human primates (NHPs). The chimpanzee adenovirus ChAd63 is undergoing evaluation in clinical trials including infants in malaria-endemic areas. Key antigens have been identified and are being used alone, in combination, or with protein subunit vaccines. Gorilla adenoviruses carrying malaria antigens are also currently being evaluated in preclinical models. These replacement adenovirus vectors will be successfully used to develop vaccines against malaria, as well as other infectious diseases.Expert commentary: Simplified prime-boost single shot regimens, dry-coated live vector vaccines or silicon microneedle arrays could be developed for malaria or other vaccines. Replacement vectors with similar or superior immunogenicity have rapidly advanced, and several are now in extensive Phase 2 and beyond in malaria as well as other diseases, notably Ebola.
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Adenovirus infections have been associated with significant morbidity and mortality in immunocompromised hosts. The clinical significance of adenovirus disease in heart transplantation is not well-defined; in particular, the signi...
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Adenovirus infections have been associated with significant morbidity and mortality in immunocompromised hosts. The clinical significance of adenovirus disease in heart transplantation is not well-defined; in particular, the significance of adenovirus identification in myocardium remains unclear. Although severe adenovirus disease has been described in heart transplant recipients, adenovirus infections seem to be more frequently associated with increased risk of adverse cardiac events, such as rejection, ventricular dysfunction, coronary vasculopathy, need for retransplantation, and graft loss because of death. Cidofovir is currently considered the standard of treatment for adenovirus disease not responding to reduction of immunosuppression.
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