The human adenovirus PI3K-Akt activator E4orf1 is targeted by the tumor suppressor p53

Human adenoviruses (HAdV) are classified as DNA tumor viruses due to their potential to mediate oncogenic transformation in non-permissive mammalian cells and certain human stem cells. To achieve transformation, the viral early proteins of the E1 and E4 regions must block apoptosis and activate proliferation: the former predominantly through modulating the cellular tumor suppressor p53 and the latter by activating cellular pro-survival and pro-metabolism protein cascades, such as the phosphoinositide 3-kinase (PI3K-Akt) pathway, which is activated by HAdV E4orf1. Focusing on HAdV-C5, we show that E4orf1 is necessary and sufficient to stimulate Akt activation through phosphorylation in H1299 cells, which is not only hindered but repressed during HAdV-C5 infection with a loss of E4orf1 function in p53-positive A549 cells. Contrary to other research, E4orf1 localized not only in the common, cytoplasmic PI3K-Akt-containing compartment, but also in distinct nuclear aggregates. We identified a novel inhibitory mechanism, where p53 selectively targeted E4orf1 to destabilize it, also stalling E4orf1-dependent Akt phosphorylation. Co-IP and immunofluorescence studies showed that p53 and E4orf1 interact, and since p53 is bound by the HAdV-C5 E3 ubiquitin ligase complex, we also identified E4orf1 as a novel factor interacting with E1B-55K and E4orf6 during infection; overexpression of E4orf1 led to less-efficient E3 ubiquitin ligase-mediated proteasomal degradation of p53. We hypothesize that p53 specifically subverts the pro-survival function of E4orf1-mediated PI3K-Akt activation to protect the cell from metabolic hyper-activation or even transformation.IMPORTANCEHuman adenoviruses (HAdV) are nearly ubiquitous pathogens comprising numerous subtypes that infect various tissues and organs. Among many encoded proteins that facilitate viral replication and subversion of host cellular processes, the viral E4orf1 protein has emerged as an intriguing yet under-investigated player in the complex interplay between the virus and its host. Nonetheless, E4orf1 has gained attention as a metabolism activator and oncogenic agent, while recent research is showing that E4orf1 may play a more important role in modulating the cellular pathways such as phosphoinositide 3-kinase-Akt-mTOR. Our study reveals a novel and general impact of E4orf1 on host mechanisms, providing a novel basis for innovative antiviral strategies in future therapeutic settings. Ongoing investigations of the cellular pathways modulated by HAdV are of great interest, particularly since adenovirus-based vectors actually serve as vaccine or gene vectors. HAdV constitute an ideal model system to analyze the underlying molecular principles of virus-induced tumorigenesis.

A viral biomolecular condensate coordinates assembly of progeny particles

Biomolecular condensates formed by phase separation can compartmentalize and regulate cellular processes1,2. Emerging evidence has suggested that membraneless subcellular compartments in virus-infected cells form by phase separation3-8. Although linked to several viral processes3-5,9,10, evidence that phase separation contributes functionally to the assembly of progeny particles in infected cells is lacking. Here we show that phase separation of the human adenovirus 52-kDa protein has a critical role in the coordinated assembly of infectious progeny particles. We demonstrate that the 52-kDa protein is essential for the organization of viral structural proteins into biomolecular condensates. This organization regulates viral assembly such that capsid assembly is coordinated with the provision of viral genomes needed to produce complete packaged particles. We show that this function is governed by the molecular grammar of an intrinsically disordered region of the 52-kDa protein, and that failure to form condensates or to recruit viral factors that are critical for assembly results in failed packaging and assembly of only non-infectious particles. Our findings identify essential requirements for coordinated assembly of progeny particles and demonstrate that phase separation of a viral protein is critical for production of infectious progeny during adenovirus infection.

Detection of Human Adenovirus, Rotavirus, and Enterovirus in Tap Water and Their Association with the Overall Quality of Water in Karachi, Pakistan

Drinking water supplies in the developing world often serve as a biosphere for various organisms. Viral gastroenteritis is a neglected area of research in Pakistan, there are no data for the prevalence of enteric viruses in drinking water of the largest city of Karachi. The present study aimed to provide a survey of the existence of enteric viruses: human adenovirus (HAdV), human enteroviruses (hEV), and genotype A rotavirus (GARV) in tap water. Using a simple PCR approach, we detected 20%, 43%, and 23% of HAdV, hEV, and GARV in tap water samples, respectively. We have also shown an overall quality deficit of tap water at the pumping station and consumer tap. We have found no sample free from bacterial contaminations. The ranges for a total number of the heterotrophic plate count and coliform were found 8.7 × 10²-4.5 × 10⁶ CFU/mL and 210 to uncountable coliforms/100 mL, respectively. Moreover, we assessed the efficiency of small-scale water treatment methods for the removal of viruses.

Quantitative Detection of Human Adenovirus and Human Rotavirus Group A in Wastewater and El-Rahawy Drainage Canal Influencing River Nile in the North of Giza, Egypt

Environmental monitoring is critical in a developing country like Egypt where there is an insufficient framework for recording and tracking outbreaks. In this study, the prevalence of human adenovirus (HAdV), rotavirus group A (RVA) was determined in urban sewage, activated sludge, drainage water, drainage sediment, Nile water, and Nile sediment, using quantitative polymerase chain reaction (qPCR) analysis. HAdV was detected in 50% of urban sewage with viral concentrations ranging from 10³ to 10⁷ genome copies/liter (GC/L), 33% of activated sludge with viral concentrations ranging from 10³ to 10⁷ GC/kilogram (GC/kg), 95% of drainage water with viral concentrations ranging from 10³ to 10⁷ GC/L, 75% of drainage sediment with viral concentrations ranging from 10³ to 10⁷ GC/L, 50% of Nile water with viral concentrations ranging from 10³ to 10⁷ GC/L, and 45% of Nile sediment with viral concentrations ranging from 10³ to 10⁷ GC/kg. RVA was detected in 50% of urban sewage with viral concentrations ranging from 10³ to 10⁷ GC/L, 75% of activated sludge with viral concentrations ranging from 10³ to 10⁷ GC/L, 58% of drainage water with viral concentrations ranging from 10³ to 10⁷ GC/L, 50% of drainage sediment with viral concentrations ranging from 10³ to 10⁷ GC/L, and 45% of Nile water with viral concentrations ranging from 10³ to 10⁷ GC/kg. In conclusion, Abu-Rawash WWTP acts as a source of HAdV and RVA, releasing them into El-Rahawy drain then to the River Nile Rosetta branch.

Generation and characterization of an Il2rg knockout Syrian hamster model for XSCID and HAdV-C6 infection in immunocompromised patients

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.

Gastroenteric Viruses Detection in a Drinking Water Distribution-to-Consumption System in a Low-Income Community in Rio de Janeiro

The availability of drinking water is one of the main determinants of quality of life, disease prevention and the promotion of health. Viruses are important agents of waterborne diseases and have been described as important markers of human faecal contamination. This study aimed to investigate viruses' presence as an indicator of drinking water quality in low-income communities in the Manguinhos area, Rio de Janeiro, Brazil. Three hundred and four drinking water samples (2L/each) were collected along the drinking water distribution-to-consumption pathway in households, as well as healthcare and school units. Water samples were collected both directly from the water supply prior to distribution and after storage in tanks and filtration units. Using qPCR, viruses were detected 50 times in 45 water samples (15%), 19 of these being human adenovirus, 17 rotavirus A and 14 norovirus GII. Viral loads recovered ranged from 5E+10 to 8.7E+10⁶ genome copies/Liter. Co-detection was observed in five household water samples and there was no difference regarding virus detection across sampling sites. Precarious and inadequate environmental conditions characterized by the lack of local infrastructure regarding basic sanitation and waste collection in the territory, as well as negligent hygiene habits, could explain viral detection in drinking water in regions with a water supply system.

Mineral Waste Containing High Levels of Iron from an Environmental Disaster (Bento Rodrigues, Mariana, Brazil) is Associated with Higher Titers of Enteric Viruses

Although the effects of heavy metals on the behavior, including infectivity, of bacteria have been studied, little information is available about their effects on enteric viruses. We report an investigation of effects on the biosynthesis of human adenoviruses (HAdV) and hepatitis A (HAV) of waters contaminated with mineral waste following an environmental disaster in Mariana City, Minas Gerais State, Brazil. The study area was affected on November 5, 2015, by 60 million m³ of mud (containing very high concentrations of iron salts) from a mining reservoir (Fundão), reaching the Gualaxo do Norte River (sites evaluated in this study), the "Rio Doce" River and finally the Atlantic Ocean. We found substantial counts of infectious HAdV and HAV (by qPCR) in all sampled sites from Gualaxo do Norte River, indicating poor basic sanitation in this area. The effects of iron on viral infection processes were evaluated using HAdV-2 and HAV-175, as DNA and RNA enteric virus models, respectively, propagated in the laboratory and exposed to this contaminated water. Experiments in field and laboratory scales found that the numbers of plaque forming units (PFU) of HAdV and HAV were significantly higher in contaminated water with high iron concentrations than in waters with low iron concentration (< 20 µg/L of iron). These findings indicate that iron can potentiate enteric virus infectivity, posing a potential risk to human and animal health, particularly during pollution disasters such as that described here in Mariana, Brazil.

Inactivation of Adenovirus in Water by Natural and Synthetic Compounds

Millions of people use contaminated water sources for direct consumption. Chlorine is the most widely disinfection product but can produce toxic by-products. In this context, natural and synthetic compounds can be an alternative to water disinfection. Therefore, the aim of this study was to assess the inactivation of human adenovirus by N-chlorotaurine (NCT), bromamine-T (BAT) and Grape seed extract (GSE) in water. Distilled water artificially contaminated with recombinant human adenovirus type 5 (rAdV-GFP) was treated with different concentrations of each compound for up to 120 min, and viral infectivity was assessed by fluorescence microscopy. The decrease in activity of the compounds in the presence of organic matter was evaluated in water supplemented with peptone. As results, NCT and GSE inactivated approximately 2.5 log₁₀ of adenovirus after 120 min. With BAT, more than 4.0 log₁₀ decrease was observed within 10 min. The oxidative activity of 1% BAT decreased by 50% in 0.5% peptone within a few minutes, while the reduction was only 30% for 1% NCT in 5% peptone after 60 min. Organic matter had no effect on the activity of GSE. Moreover, the minimal concentration of BAT and GSE to kill viruses was lower than that known to kill human cells. It was concluded that the three compounds have potential to be used for water disinfection for drinking or reuse purposes.

Evaluation of Bacterial Contamination as an Indicator of Viral Contamination in a Sedimentary Aquifer in Uruguay

In Uruguay, groundwater is frequently used for agricultural activities, as well as for human consumption in urban and rural areas. As in many countries worldwide, drinking water microbiological quality is evaluated only according to bacteriological standards and virological analyses are not mentioned in the legislation. In this work, the incidence of human viral (Rotavirus A, Norovirus GII, and human Adenovirus) and bacterial (total and thermotolerant coliform and Pseudomonas aeruginosa) contamination in groundwater in the Salto district, Uruguay, as well as the possible correlation between these groups of microorganisms, was studied. From a total of 134 groundwater samples, 42 (32.1%) were positive for Rotavirus, only 1 (0.7%) for both Rotavirus and Adenovirus, and 96 (72.6%) samples were positive for bacterial indicators. Results also show that Rotavirus presence was not associated with changes in chemical composition of the aquifer water. Bacteriological indicators were not adequate to predict the presence of viruses in individual groundwater samples (well scale), but a deeper spatial-temporal analysis showed that they are promising candidates to assess the viral contamination degree at aquifer scale, since from the number of wells with bacterial contamination the number of wells with viral contamination could be estimated.

Assessment of the Virological Quality of Marine and Running Surface Waters in NW Greece: A Case Study

The virological quality of surface marine and running water samples collected from Igoumenitsa gulf and Kalamas river (NW Greece) was assessed from October 2012 to September 2013. Sampling sites were exposed to different land and/or anthropogenic effects. Seawater samples were collected monthly from five sampling stations (new harbor, old harbor, wastewater treatment plant outlet, protected Natura area, Drepano beach). Viral targets included human adenoviruses (hAdVs), as index human viruses, while noroviruses (NoVs) and hepatitis A virus (HAV) were also studied. Kalamas river samples were collected seasonally, from three sampling stations (Soulopoulo, Dam, Sagiada-estuaries), while viral targets included also porcine adenoviruses (pAdVs) and bovine polyoma viruses (bPyVs), as additional index viruses. All water samples were analyzed for standard bacterial indicators, as well. Physicochemical and meteorological data were also collected. Based on the standard bacterial indices, both sea and river water samples did not exceed the limits set according to Directive 2006/7/EU. However, positive samples for hAdVs were found occasionally in all sampling sites in Igoumenitsa gulf (23.3%, 14/60) showing fecal contamination of human origin. Moreover, HAV was detected once, in the sampling site of the old port (at 510 GC/L). Most of the Kalamas water samples were found positive for hAdVs (58.3%, 7/12), while human noroviruses GI (NoVGI) (8.3%, 1/12) and GII (NoVGII) (16.7%, 2/12) were also detected. HAV, pAdVs, and bovine polyomaviruses (bPyVs) were not detected in any of the analyzed samples. No statistically significant correlations were found between classic bacterial indicators and viral targets, nor between viruses and meteorological data. Overall, the present study contributed to the collection of useful data for the biomonitoring of the region, and the assessment of the overall impact of anthropogenic activities. It provided also valuable information for the evaluation of the risk of waterborne viral infections and the protection of public health. It was the first virological study in the area and one of the few in Greece.

Human adenovirus in tissues of freshwater snails living in contaminated waters

Human adenovirus (HAdV) is resistant to environment and can be used as a marker to detect fecal contamination. Considering the importance of freshwater snails in the aquatic environment, their use as concentrators for HAdV is a complementary tool for viral analysis of water. The goal of the study was to detect HAdV in snails and surface water collected from wetlands of the Sinos River (Rio Grande do Sul, Brazil) basin and to compare rates and viral loads found in both samples. HAdV was detected through real-time PCR. Total and fecal coliforms were detected by Colilert^® kit, and viral infectivity of positive samples of the DNA genome was performed in A549 human cell line. All wetlands presented bacterial and viral contamination, but no viral particle was considered viable. The wetland that showed lower fecal coliform mean was Campo Bom, and São Leopoldo (both cities in Rio Grande do Sul) was representative of the highest mean. HAdV was detected in water samples (53%), gastropods' hemolymph (31%) and tissues (16%). Wetlands proved to be environments already altered by human action. Water samples exhibited a higher frequency of HAdV detection; however, in some instances, the target viral genomes were only found in gastropod biological samples. This was a pioneer study in the use of freshwater snails for human enteric viral assessment thus demonstrating that the human organism can retain fecal contamination, complementing and assisting in microbiological water analyzes.

Adenovirus Type 7 Pneumonia in Children Who Died from Measles-Associated Pneumonia, Hanoi, Vietnam, 2014

During a 2014 measles outbreak in Vietnam, postmortem pathologic examination of hospitalized children who died showed that adenovirus type 7 pneumonia was a contributory cause of death in children with measles-associated immune suppression. Adenovirus type 7 pneumonia should be recognized as a major cause of secondary infection after measles.

Tracking Human Adenovirus Inactivation by Gamma Radiation under Different Environmental Conditions

Adenovirus is the most prevalent enteric virus in waters worldwide due to its environmental stability, which leads to public health concerns. Mitigation strategies are therefore required. The aim of this study was to assess the inactivation of human adenovirus type 5 (HAdV-5) by gamma radiation in aqueous environments. Various substrates with different organic loads, including domestic wastewater, were inoculated with HAdV-5 either individually or in a viral pool (with murine norovirus type 1 [MNV-1]) and were irradiated in a Cobalt-60 irradiator at several gamma radiation doses (0.9 to 10.8 kGy). The infectivity of viral particles, before and after irradiation, was tested by plaque assay using A549 cells. D10 values (dose required to inactivate 90% of a population or the dose of irradiation needed to produce a 1 log10 reduction in the population) were estimated for each substrate based on virus infectivity inactivation exponential kinetics. The capability of two detection methods, nested PCR and enzyme-linked immunosorbent assay (ELISA), to track inactivated viral particles was also assessed. After irradiation at 3.5 kGy, a reduction of the HAdV-5 titer of 4 log PFU/ml on substrates with lower organic loads was obtained, but in highly organic matrixes, the virus titer reduction was only 1 log PFU/ml. The D10 values of HAdV-5 in high organic substrates were significantly higher than in water suspensions. The obtained results point out some discrepancies between nested PCR, ELISA, and plaque assay on the assessments of HAdV-5 inactivation. These results suggest that the inactivation of HAdV-5 by gamma radiation, in aqueous environments, is significantly affected by substrate composition. This study highlights the virucidal potential of gamma radiation that may be used as a disinfection treatment for sustainable water supplies.

IMPORTANCE

Human adenovirus (HAdV) is the most prevalent of the enteric viruses in environmental waters worldwide. The purposes of this study are to provide new insights on the inactivation of enteric virus by gamma irradiation and to introduce new concepts and reinforce the benefits and utility of radiation technologies as disinfection processes. This may be an effective tool to guarantee the reduction of viral pathogens and to contribute to public health and sustainable water supplies.

Detection of human adenoviruses in organic fresh produce using molecular and cell culture-based methods

The consumption of organic fresh produce has increased in recent years due to consumer demand for healthy foods without chemical additives. However, the number of foodborne outbreaks associated with fresh produce has also increased. Contamination of food with enteric viruses is a major concern because the viruses have a low infectious dose and high persistence in the environment. Human adenovirus (HAdV) has been proposed as a good marker of faecal contamination. Therefore, the aim of this study was to evaluate the efficiency of the plaque assay (PA), real time PCR (qPCR) and integrated cell culture-RT-qPCR (ICC-RT-qPCR) for the recovery of HAdV from artificially and naturally contaminated fresh produce. Organic lettuce, strawberries and green onions were selected because these fresh products are frequently associated with foodborne outbreaks. The virus extraction efficiencies from artificially contaminated samples varied from 2.8% to 32.8% depending on the food matrix and the quantification method used. Although the HAdV recoveries determined by qPCR were higher than those determined by PA and ICC-RT-qPCR, PA was defined as the most reproducible method. The qPCR assays were more sensitive than the PA and ICC-RT-qPCR assays; however, this technique alone did not provide information about the viability of the pathogen. ICC-RT-qPCR was more sensitive than PA for detecting infectious particles in fresh produce samples. HAdV genome copies were detected in 93.3% of the analysed naturally contaminated samples, attesting to the common faecal contamination of the fresh produce tested. However, only 33.3% of the total samples were positive for infectious HAdV particles based on ICC-RT-qPCR. In conclusion, this study reported that HAdV can be an efficient viral marker for fresh produce contamination. Good detection of infectious HAdV was obtained with the ICC-RT-qPCR and PA assays. Thus, we suggest that the ICC-RT-qPCR and PA assays should be considered when quantitative microbial risk assessment (QMRA) studies are required and to establish reliable food safety guidelines.

Aggregation of Adenovirus 2 in Source Water and Impacts on Disinfection by Chlorine

It is generally accepted that viral particles in source water are likely to be found as aggregates attached to other particles. For this reason, it is important to investigate the disinfection efficacy of chlorine on aggregated viruses. A method to produce adenovirus particle aggregation was developed for this study. Negative stain electron microscopy was used to measure aggregation before and after addition of virus particles to surface water at different pH and specific conductance levels. The impact of aggregation on the efficacy of chlorine disinfection was also examined. Disinfection experiments with human adenovirus 2 (HAdV2) in source water were conducted using 0.2 mg/L free chlorine at 5 °C. Aggregation of HAdV2 in source water (≥3 aggregated particles) remained higher at higher specific conductance and pH levels. However, aggregation was highly variable, with the percentage of particles present in aggregates ranging from 43 to 71 %. Upon addition into source water, the aggregation percentage dropped dramatically. On average, chlorination CT values (chlorine concentration in mg/L × time in min) for 3-log10 inactivation of aggregated HAdV2 were up to three times higher than those for dispersed HAdV2, indicating that aggregation reduced the disinfection rate. This information can be used by water utilities and regulators to guide decision making regarding disinfection of viruses in water.

Behaviour and recovery of human adenovirus from tropical sediment under simulated conditions

This study assessed the contributions of pH and organic matter (OM) on the recovery of infectious human adenovirus 5 (HAdV-5) and genome copies (GCs) in waters that were artificially contaminated with tropical soil. The use of a mathematical equation was proposed based on the flocculation index of clay to assess the recovery of total GCs in these controlled assays. The results suggest that solids in the water reduced the viral genome copy loads per millilitre (GC · mL(-1)) and viral infectivity. OM did not influence the GC · mL(-1) recovery rate (p > 0.05) but led to a 99% (2 log10) reduction in plaque-forming unit counts per millilitre (PFU/mL), which indicates that infectivity and gene integrity were non-related parameters. Our findings also suggest that acidic pH levels hinder viral inactivation and that clay is the main factor responsible for the interactions of HAdV-5 with soil. These findings may be useful for future eco-epidemiological investigations and studies of viral inactivation or even as parameters for future research into water quality analysis and water treatment.

[Rescue and Amplification of Recombinant Human Adenovirus Type 41 in 293 Cells]

Human adenovirus type 41 (HAdV-41) is considered to be a "fastidious adenovirus". E1-deleted HAdV-41 cannot be rescued or amplified in 293 cells. To propagate recombinant HAdV-41 in 293 cells, the backbone plasmid pAdbone41 was reconstructed. That is, the E3 coding sequence of HAdV-41 was deleted and replaced with the HAdV-5 E4orf6 gene; and the E1A enhancer of HAdV-5 was inserted upstream of the E4 promoter of HAdV-41. Novel adenoviral plasmid pAd41E4EE-GFP was generated by homologous recombination of the shuttle plasmid pSh41-GFP with the modified backbone plasmid in the Escherichia coli BJ5183 strain. Adenovirus HAdV-41-E4EE-GFP was rescued by transfecting 293 cells with linearized pAd41E4EE-GFP. After seven rounds of propagation, viruses were purified by the CsCl ultracentrifugation method. HAdV-41-E4EE-GFP in 1.0 ml with a particle titer of 8 x 10(10) vp/mL was obtained which had a particle-to-infectious ratio of 50 : 1. The genome of HAdV-41-E4EE-GFP was confirmed by restriction analyses and polymerase chain reaction. These results showed that a novel HAdV-41 vector system was established in which recombinant HAdV-41 could be constructed and packaged in 293 cells.

Effect of UV light on the inactivation of recombinant human adenovirus and murine norovirus seeded in seawater in shellfish depuration tanks

Shellfish depuration is a process that aims to eliminate pathogens from mollusk tissues. Seawater disinfection during the depuration process is important and ultraviolet (UV) light treatment is the most used method worldwide. Viral models are usually employed as surrogates of fastidious viruses in viability studies. The aim of this study was to employ methods based on green fluorescent protein (GFP) fluorescence and plaque forming units to detect, respectively, recombinant adenovirus (rAdV-GFP) and murine norovirus (MNV) artificially seeded in environmental matrices. These assays were applied to assess the inactivation of rAdV-GFP and MNV in seawater in recirculation shellfish depuration tanks with and without UV light treatment. Kinetics of rAdV GFP-expression was previously measured by UV-spectrophotometer. Flow cytometry (FC), fluorescence microscopy (FM), and plaque assay were used to determine virus titer and detection limits. The influence of the environmental matrix on the performance of the methods was prior determined using either drinking water or filtered seawater seeded with rAdV-GFP. Disinfection of seeded seawater was evaluated with and without UV treatment. The time of 24-h post-infection was established as ideal for fluorescence detection on rAdV-GFP infected cells. FC showed lower sensitivity, when compared to FM, which was similar to plaque assay. Seawater disinfection on depuration tanks was promising and rAdV-GFP declined 99.99 % after 24 and 48 h with and without UV treatment, respectively. MNV was completely inactivated after 24 h in both treatments. As conclusion, the depuration tanks were effective to inactivate rAdV-GFP and MNV and the UV disinfection treatment accelerated the process.

A One Year Study on the Concentrations of Norovirus and Enteric Adenoviruses in Wastewater and A Surface Drinking Water Source in Norway

Enteric viruses transmitted via the faecal-oral route occur in high concentrations in wastewater and may contaminate drinking water sources and cause disease. In order to quantify enteric adenovirus and norovirus genotypes I and II (GI and GII) impacting a drinking source in Norway, samples of surface water (52), wastewater inlet (64) and outlet (59) were collected between January 2011 and April 2012. Samples were concentrated in two steps, using an electropositive disc filter and polyethylene glycol precipitation, followed by nucleic acid extraction and analysis by quantitative polymerase chain reaction. Virus was detected in 47/52 (90.4%) of surface water, 59/64 (92%) of wastewater inlet and 55/59 (93%) of wastewater outlet samples. Norovirus GI occurred in the highest concentrations in surface water (2.51e + 04) and adenovirus in wastewater (2.15e + 07). While adenovirus was the most frequently detected in all matrices, norovirus GI was more frequently detected in surface water and norovirus GII in wastewater. This study is the first in Norway to monitor both sewage and a drinking water source in parallel, and confirms the year-round presence of norovirus and adenovirus in a Norwegian drinking water source.

Capsid-Damaging Effects of UV Irradiation as Measured by Quantitative PCR Coupled with Ethidium Monoazide Treatment

The damage to a viral capsid after low-pressure (LP) and medium-pressure (MP) UV irradiation was assessed, using the quantitative or quantitative reverse transcription PCR coupled with ethidium monoazide treatment (EMA-PCR). After UV irradiation, adenovirus 5 (Ad5) and poliovirus 1 (PV1) were subjected to a plaque assay, PCR, and EMA-PCR to investigate the effect of UV irradiation on viral infectivity, genome damage, and capsid damage, respectively. The effectiveness of UV wavelengths in a viral genome and capsid damage of both PV1 and Ad5 was also further investigated using a band-pass filter. It was found that an MPUV lamp was more effective than an LPUV lamp in inactivating Ad5, whereas there was no difference in the case of PV1. The results of viral reduction determined by PCR and EMA-PCR indicated that MP UV irradiation damaged Ad5 capsid. The damage to PV1 and Ad5 capsid was also not observed after LP UV irradiation. The investigation of effects of UV wavelengths suggested that UV wavelengths at 230-245 nm have greater effects on adenovirus capsid in addition to viral genome than UV wavelengths beyond 245 nm.

[Morphogenetic study of human adenovirus type 41 in 293TE cells]

To investigate the morphogenetic process of human adenovirus type 41 (HAdV-41), 293TE cells were infected with purified wild-type HAdV-41, and ultrathin sections of infected cells were prepared and observed under a transmission electron microscope. Results showed that HAdV-41 entered host cells mainly through three ways: non-clathrin-coated pit, clathrin-coated pit, and direct penetration of plasma membrane. In addition, cell microvilli might help HAdV-41 enter cells. After entering into cells, HAdV-41 virus particles could be found in vacuoles or lysosomes or be in a free state in cytoplasm. Only free virus particles could be found near nuclear pores (NP), suggesting that the virus needed to escape from lysosomes for effective infection and viral nucleoprotein entered the nucleus through NP. Progeny viruses were as-sembled in the nucleus. Three types of inclusion bodies, which were termed as fibrillous inclusion body, condense inclusion body, and stripped condense inclusion body, were involved in HAdV-41 morphogenesis. In the late phase of viral replication, the membrane integrity of the infected cells was lost and viral particles were released extracellularly. This study reveals the partial process of HAdV-41 morphogenesis and provides more biological information on HAdV-41.

Anti-tumor effects of an oncolytic adenovirus expressing hemagglutinin-neuraminidase of Newcastle disease virus in vitro and in vivo

Oncolytic virotherapy has been an attractive drug platform for targeted therapy of cancer over the past few years. Viral vectors can be used to target and lyse cancer cells, but achieving good efficacy and specificity with this treatment approach is a major challenge. Here, we assessed the ability of a novel dual-specific anti-tumor oncolytic adenovirus, expressing the hemagglutinin-neuraminidase (HN) gene from the Newcastle disease virus under the human telomerase reverse transcriptase (hTERT) promoter (Ad-hTERTp-E1a-HN), to inhibit esophageal cancer EC-109 cells in culture and to reduce tumor burden in xenografted BALB/c nude mice. In vitro, infection with Ad-hTERT-E1a-HN could inhibit the growth of EC-109 cells significantly and also protect normal human liver cell line L02 from growth suppression in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Ad-hTERT-E1a-HN also effectively and selectively decreased the sialic acid level on EC-109 cells, but not on L02 cells. Furthermore, Ad-hTERT-E1a-HN was shown to induce the apoptosis pathway via acridine orange and ethidium bromide staining (AO/EB staining), increase reactive oxygen species (ROS), reduce mitochondrial membrane potential and release cytochrome c. In vivo, xenografted BALB/c nude mice were treated via intratumoral or intravenous injections of Ad-hTERT-E1a-HN. Although both treatments showed an obvious suppression in tumor volume, only Ad-hTERT-E1a-HN delivered via intratumoral injection elicited a complete response to treatment. These results reinforced previous findings and highlighted the potential therapeutic application of Ad-hTERT-E1a-HN for treatment of esophageal cancer in clinical trials.

Prevalence of respiratory adenovirus species B and C in sewage sludge

Human adenovirus diversity in sewage sludge was assessed by Ion Torrent sequencing and annotation of partial adenovirus hexon genes. The most abundant species identified were HAdV-C (average 78%) and -B (average 20%), which are associated with respiratory infections. These findings reinforce the necessity to consider aerosol exposure to sewage-derived pathogens.

[Modelling of the adeno-herpetic infection in lymphoblastoid cell cultures]

Viral infections take the key place in medical practice. A large group of diseases are caused by adenoviral and herpes infection. As a rule, the investigations carried out in scientific laboratories are directed to the study of certain aspects of the interaction between the virus and the cell on the model of single infection. At the same time different viral infections at the level of macroorganism are constantly interacting with each other. The paper presents the studies on the selection of optimal models of lymphoblastoid cell lines for analysis of peculiarities of the mixed adeno-herpetic infection. The reproduction of human adenovirus type 5 and Epstein-Barr virus in the mono- and mixed infection in lymphoblastoid cell cultures of B-phenotype: B95-8, Raji, Namalwa have been studied. Both interfering and inhibiting action of viruses are shown. So EBV, which has a short 48-hour cycle of reproduction, inhibits the adenovirus at the given time. The obtained cell models of adeno-herpes infection will allow to study peculiarities of the antiviral action of etiotropic antiviral preparations in conditions of coinfection.

Characterization of species C human adenovirus serotype 6 (Ad6)

Adenovirus serotype (Ad5) is the most studied Ad. Ad1, 2, and 6 are also members of species C Ad and are presumed to have biologies similar to Ad5. In this work, we have compared the ability of Ad1, 2, 5, and 6 to infect liver and muscle after intravenous and intramuscular injection. We found that Ad6 was surprisingly the most potent at liver gene delivery and that Ad1 and Ad2 were markedly weaker than Ad5 and 6. To understand these differences, we sequenced the Ad6 genome. This revealed that the Ad6 fiber protein is surprisingly three shaft repeats shorter than the others which may explain differences in virus infectivity in vitro, but not in the liver. Comparison of hexon hypervariable regions (HVRs) suggests that the higher transduction by Ad5 and 6 as compared to Ad1 and 2 may be related to differences in charge and length.

Inactivation of herpes simplex virus type 1 & adenovirus type 5 by direct electric current at a biocompatible level in vitro

BACKGROUND

In vitro studies were conducted to quantify the effectiveness of low-level direct electric current (DC) on infectivity of Herpes Simplex Virus type 1 (HSV-1), Adenovirus type 5 (AdV-5), and on viability of Vero cells.

METHODS

Both viruses and Vero cells were exposed to DC by using platinum electrodes connected to a DC source, then the viral infectivity and cell viability were assessed by plaque and MTT assay, respectively.

RESULTS

The results showed that both viruses were inactivated completely by 200 microA DC in 10 minutes (current density = 20 microA/mm2) while this amount of DC had no significant changes on the viability of Vero cells (viability > 90 %). Inactivation degree of HSV-1 and AdV-5 was 5 and 4 log per mL, respectively. Further study is required to investigate the mechanism of inactivation by this method.

CONCLUSIONS

DC at a biocompatible level showed the competency to inactivate the viruses in the solution completely. So it is a useful tool for designing a noninvasive method for decontamination of biological or synthetic fluids. This method or derivation can be considered as an easy, fast, and economical method for fluid decontamination.

Cultivation for 21 days should be considered to isolate respiratory adenoviruses from samples containing small numbers of adenoviral genomes

Adenovirus types 1, 2, and 3 can usually be isolated in only a short time, although occasionally it may take longer. This phenomenon has been explained empirically as being due to the viral load in the sample, although to date there has been no experimental confirmation of this. In this study we therefore tried to establish a correlation between the quantity of respiratory adenovirus genome in the clinical sample and the time required for its isolation. The correct choice of sensitive cell line is important for this purpose, thus we compared the sensitivity of three different cell lines (HeLa, A549, and RD), and found A549 to be the most sensitive to adenoviruses 1-3. Stored clinical samples (n=21) containing adenoviruses 1-3 were diluted to make solutions containing between 10 and 10(8) copies/microL of adenovirus genome (n=242). These diluted clinical samples were then inoculated into A549 cells, which were cultivated for 21 days and the results compared to the number of viral genomes in each cultivated sample. Adenoviruses could be isolated from all samples (41/41) containing >/=10(6) copies/microL within 6 days, whereas samples containing 10 and 10(2) copies/microL required cultivation for 12.6+/-3.8 and 11.2+/-3.8 days (mean+/-S.D.), respectively, before adenoviruses could be isolated. A cultivation time of 21 days should therefore be considered for the isolation of respiratory adenoviruses from samples containing <10(3) adenovirus genome copies/microL.

A capsid-encoded PPxY-motif facilitates adenovirus entry

Viruses use cellular machinery to enter and infect cells. In this study we address the cell entry mechanisms of nonenveloped adenoviruses (Ads). We show that protein VI, an internal capsid protein, is rapidly exposed after cell surface attachment and internalization and remains partially associated with the capsid during intracellular transport. We found that a PPxY motif within protein VI recruits Nedd4 E3 ubiquitin ligases to bind and ubiquitylate protein VI. We further show that this PPxY motif is involved in rapid, microtubule-dependent intracellular movement of protein VI. Ads with a mutated PPxY motif can efficiently escape endosomes but are defective in microtubule-dependent trafficking toward the nucleus. Likewise, depletion of Nedd4 ligases attenuates nuclear accumulation of incoming Ad particles and infection. Our data provide the first evidence that virus-encoded PPxY motifs are required during virus entry, which may be of significance for several other pathogens.

[Modern tendencies in the study of human viruses]

The results of fundamental and applied researches of the Department of Molecular Biology of Viruses and Virus Reproduction Laboratory created on its basis, for the recent five years are generalized in this paper. The basic trends of research of fundamental regularities of virus-cell interaction, search of the anti-virus substances, new approaches to diagnosis of human viruses were analyzed. The spectrum of practical development of the Laboratory, which includes preparations for diagnostics and treatment of human diseases, is presented.

A rapid and sensitive assay for detection of replication-competent adenoviruses by a combination of microcarrier cell culture and quantitative PCR

The development of a rapid and sensitive assay for detection of replication-competent adenoviruses (RCAs) is described. This RCA assay consists of an incubation step of 4 days of adenoviral vectors on A549 cells in a microcarrier cell culture system followed by detection of amplified RCAs by E1-specific quantitative PCR. The detection limit of this assay is 3 RCAs in 1 x 10(10) vector particles per 70 ml of microcarrier cell culture. The main advantage of the combination of cell culture and PCR detection is that replicated virus can be detected long before cytopathic effects become visible and therefore, it is much faster than conventional cell culture-based assays. This assay was validated by spiking replication-incompetent adenoviral vectors with wild-type adenovirus serotype 5 (wt Ad5) as a positive control for RCA. It was found that the replication of wt Ad5 is hampered above a vector particle per cell ratio of 50. However, if microcarrier beads are used, many cells can be grown in a small suspension culture and consequently a large number of vector particles can be tested for contamination with RCA.

Growth and purification of enteric adenovirus type 40

The enteric adenoviruses of subgroup F (Ad40 and Ad41) pose some special problems of cultivation, as they cannot be readily passaged in many of the cell types used to propagate the more commonly used subgroup C serotypes (Ad2 and Ad5) and there is no standard plaque assay. Methods to propagate Ad40 in complementing cell lines and to evaluate infectivity and particle number are presented in this chapter.

Silencing E1A mRNA by RNA interference inhibits adenovirus replication

The adenovirus family contains 51 human serotypes, and most human adenoviruses cause widespread respiratory tract infections. Adenovirus infections can result in severe complications in some cases, such as in adenovirus type 11 infection in immunocompromised patients. However, effective treatment methods for adenovirus infections are currently unavailable. This prompted the search for antiviral agents effective against adenovirus infections. In the present study, adenovirus E1A was targeted by RNA interference (RNAi) using synthetic small interfering RNAs (siRNAs) in an attempt to inhibit viral replication, since adenovirus E1A proteins are known to be involved in the transcriptional activation of the viral and cellular genes necessary for controlling the cell cycle and viral replication. The results indicated that the siRNAs effectively reduced the amount of adenovirus E1A mRNA and the levels of replicative intermediates. Additionally, siRNA-mediated gene silencing inhibited adenovirus replication by suppressing the E1A mRNA. These results suggest that the RNAi-mediated targeting of adenovirus E1A may have a potentially therapeutic effect in controlling adenovirus infections.

Improved growth of enteric adenovirus type 40 in a modified cell line that can no longer respond to interferon stimulation

Human enteric adenoviruses propagate poorly in conventional human cell lines used to grow other adenovirus serotypes. As human enteric adenoviruses have a defect in counteracting the cellular interferon (IFN) response in cell culture, to aid in growth of the virus, a 293-based cell line defective in its ability to respond to IFN was constructed. This cell line (293-SV5/V) constitutively expresses V-protein of the paramyxovirus Simian virus 5, which degrades the signal transducer and activator of transcription 1 (STAT1) and thereby prevents the STAT1-mediated IFN response. Analysis of human enteric adenovirus type 40 (HAdV-40)-infected 293-SV5/V cells compared with parental 293 cells shows that the recombinant line allows more rapid production of virus and results in higher titres. These results suggest that the defect in HAdV-40 in counteracting the IFN response can be overcome at least partially through the use of 293-SV5/V cell lines.

Transcriptional profiling of batch and fed-batch protein-free 293-HEK cultures

Dynamic nutrient feeding to control glutamine at low levels in protein-free fed-batch cultures of 293-human embryonic kidney (HEK) cells achieved cell concentrations of 6 x 10(6) cells/ml. This represented a 4-fold improvement in cell concentration compared to batch cultures. Reduction in glutamine and glucose consumption, as well as lactate and ammonia production, were also observed in these fed-batch cultures. High virus production titers of 3 x 10(11) pfu/ml were achieved in fed-batch cultures which were 10,000-fold higher than batch cultures. An investigation of the transcriptional regulation of the metabolic changes associated with the batch and the low-glutamine fed-batch cultures using DNA microarray was conducted. This analysis provides better understanding of the transcriptional regulatory mechanism resulting in the observed physiological changes. Transcriptional profiling of cells from the mid-exponential, late exponential and stationary phases of both the batch and fed-batch were undertaken using an 18,000 element human chip. Transcriptional profiles were ontologically classified to provide a global view of the genetic changes. Furthermore, a pathway-oriented analysis focusing on cellular metabolism was conducted to reveal the dynamic regulation of genes related to amino acid metabolism, tRNA synthetases, TCA cycle, electron transport chain and glycolysis.

Generation of a novel replication-incompetent adenoviral vector derived from human adenovirus type 49: manufacture on PER.C6 cells, tropism and immunogenicity

Recombinant adenoviral vectors based on type 5 (rAd5) show great promise as a vaccine carrier. However, neutralizing activity against Ad5 is prevalent and high-titred among human populations, and significantly dampens Ad5-based vaccine modalities. The generation of alternative adenoviral vectors with low seroprevalence thus receives much research attention. Here, it is shown that a member from human adenovirus subgroup D, i.e. Ad49, does not cross-react with Ad5 neutralizing activity, making it a candidate serotype for vector development. Therefore, a plasmid system that allows formation of replication-incompetent adenovirus serotype 49 vaccine vectors (rAd49) was constructed and it was demonstrated that rAd49 can be successfully propagated to high titres on existing Ad5.E1-complementing cell lines such as PER.C6. Using an rAd49 vector carrying the luciferase marker gene, detailed seroprevalence studies were performed, demonstrating that rAd49 has low seroprevalence and neutralizing antibody titres worldwide. Also, we have initiated rAd49 vector receptor usage suggesting that rAd49 utilizes hCD46 as a cellular receptor. Finally, the immunogenicity of the rAd49 vector was assessed and it was shown that an rAd49.SIVGag vaccine induces strong anti-SIVGag CD8+ T-lymphocytes in naïve mice, albeit less than an rAd5.SIVGag vaccine. However, in mice with high anti-Ad5 immunity the rAd5.SIVGag vaccine was severely blunted, whereas the anti-SIVGag response was not significantly suppressed using the rAd49.SIVGag vaccine. These data demonstrate the potential of a replication deficient human group D adenoviral vector for vaccination purposes.

Co-infections of adenovirus species in previously vaccinated patients

Adenoviral infections associated with respiratory illness in military trainees involve multiple co-infecting species and serotypes.

Despite the success of the adenovirus vaccine administered to US military trainees, acute respiratory disease (ARD) surveillance still detected breakthrough infections (respiratory illnesses associated with the adenovirus serotypes specifically targeted by the vaccine). To explore the role of adenoviral co-infection (simultaneous infection by multiple pathogenic adenovirus species) in breakthrough disease, we examined specimens from patients with ARD by using 3 methods to detect multiple adenoviral species: a DNA microarray, a polymerase chain reaction­ (PCR)–enzyme-linked immunosorbent assay, and a multiplex PCR assay. Analysis of 52 samples (21 vaccinated, 31 unvaccinated) collected from 1996 to 2000 showed that all vaccinated samples had co-infections. Most of these co-infections were community-acquired serotypes of species B1 and E. Unvaccinated samples primarily contained only 1 species (species E) associated with adult respiratory illness. This study highlights the rarely reported phenomenon of adenoviral co-infections in a clinically relevant environment suitable for the generation of new recombinational variants.

Efficacy of topical cobalt chelate CTC-96 against adenovirus in a cell culture model and against adenovirus keratoconjunctivitis in a rabbit model

BACKGROUND

Adenovirus (Ad), associated with significant morbidity, has no topical treatment. A leading CTC compound (CTC-96), a Co(III) chelate, was found to have potent in vitro and in vivo antiviral efficacy against herpes viruses. In this study CTC-96 is being tested for possible anti-Adenovirus activity.

METHODS

The biological anti-adenovirus activity of CTC-96 in concentrations from 5 to 250 ug/ml, was evaluated initially by viral inactivation (viral exposure to CTC-96 followed by dilution and inoculation of cells), virucidal (viral exposure to CTC-96 and inoculation of cells without dilution) and antiviral (effect of CTC-96 on previously adsorbed virus) plaque assays on HeLa (human cervical carcinoma), A549 (human lung carcinoma) and SIRC (rabbit corneal) cells. After verifying the antiviral activity, New Zealand White rabbits were infected with Ad-5 into: 1) the anterior cul-de-sac scarifying the conjunctiva (Group "C+"); 2) the anterior cul-de-sac scarifying the conjunctiva and cornea (Group "CC+"); 3) the stroma (Group "CI+"). Controls were sham-infected ("C-", "CC-", "CI-"). Other rabbits, after "CC", were treated for 21 days with: 1) placebo, 9x/day ("-"); 2) CTC-96, 50 ug/ml, 9x/day ("50/9"); CTC-96, 50 ug/ml, 6x/day ("50/6"); CTC-96, 25 ug/ml, 6x/day ("25/6"). All animals were monitored via examination and plaque assays.

RESULTS

In vitro viral inactivation, virucidal and antiviral assays all demonstrated CTC-96 to be effective against Adenvirus type 5 (ad-5). The in vivo model of Ad keratoconjunctivitis most similar to human disease and producing highest viral yield was "CC". All eyes (6/6) developed acute conjunctivitis. "CI" yielded more stromal involvement (1/6) and iritis (5/6), but lower clinical scores (area x severity). Infection via "C" was inconsistent (4/6). Fifty (50) ug/ml was effective against Ad-5 at 6x, 9x dosings while 25 ug/ml (6x) was only marginally effective.

CONCLUSION

CTC-96 demonstrated virucidal activity against Ad5 in tissue culture with HeLa, A549 and SIRC cell lines. Animal Model Development: 1) "CC" produced conjunctival infection with occasional keratitis similar to human disease; "CI" yielded primarily stromal involvement; 2) "C" consistently produced neither conjunctivitis nor keratitis.CTC Testing: 1) Conjunctivitis in all eyes; 2) Resolution fastest in "50/9" ("50/9". "50/6" > "25/6" > "-"); 3) Efficacy in "50/6" was not statistically different than "50/9"; 4) Conjunctival severity was lower in treatment groups then controls; 5) Little corneal or intra-ocular changes were noted.

The Arg279Gln [corrected] substitution in the adenovirus type 11p (Ad11p) fiber knob abolishes EDTA-resistant binding to A549 and CHO-CD46 cells, converting the phenotype to that of Ad7p

The major determinant of adenovirus (Ad) attachment to host cells is the C-terminal knob domain of the trimeric fiber protein. Ad type 11p (Ad11p; species B2) in contrast to Ad7p (species B1) utilizes at least two different cellular attachment receptors, designated sBAR (species B adenovirus receptor) and sB2AR (species B2 adenovirus receptor). CD46 has recently been identified as one of the Ad11p attachment receptors. However, CD46 did not seem to constitute a functional receptor for Ad7p. Although Ad7p shares high knob amino acid identity with Ad11p, Ad7p is deficient in binding to both sB2AR and CD46. To determine what regions of the Ad11p fiber knob are necessary for sB2AR-CD46 interaction, we constructed recombinant fiber knobs (rFK) with Ad11p/Ad7p chimeras and Ad11p sequences having a single amino acid substitution from Ad7p. Binding of the constructs to A549 and CHO-CD46 BC1 isoform-expressing cells was analyzed by flow cytometry. Our results indicate that an Arg279Gln [corrected] substitution is sufficient to convert the Ad11p receptor-interaction phenotype to that of Ad7p and abolish sB2AR and CD46 interaction. Also a Glu279Arg substitution in Ad7p rFKs increases CD46 binding. Thus, the lateral HI loop of the Ad11p fiber knob seems to be the key determinant for Ad11p sB2AR-CD46 interaction. This result is comparable to another non-coxsackie-adenovirus receptor binding Ad (Ad37p), where substitution of one amino acid abolishes virus-cell interaction. In conjunction with previous results, our findings also strongly suggest that sB2AR is equivalent to CD46.

Comparative inactivation of adenovirus serotypes by UV light disinfection

The results of this study confirm that adenoviruses are the most resistant enteric viruses to inactivation by UV light and that adenovirus 40 appears to be the most resistant. The effect of freeze-thawing and storage in water may affect the sensitivity of some adenoviruses to inactivation by UV light.

[Effect of qingfei oral liquid on protein expression of transforming growth factor-beta1 and platelet derived growth factor-BB of adenovirus type 3I, 7b induced human embryonic lung fibroblast cells]

OBJECTIVE

To explore the effect of qingfei oral liquid (QOL) contained serum on protein expression of transforming growth factor-beta1 (TGF-beta1) and platelet derived growth factor-BB (PDGF-BB) of adenovirus type 3I, 7b induced human embryonic lung fibroblast cells.

METHODS

The cells were divided into 5 groups, the normal cells group (NCG), the virus control group (VCG), the blank serum group (BSG), the ribavirin group (RVG) and the QOL contained serum group (QSG). All the cells except those in the NCG were challenged by adenovirus type 3I, 7b and treated with correspondent medicine. The contents of TGF-beta1 and PDGF-BB in the supernatant of cell culture were monitored by ELISA and compared among groups.

RESULTS

Contents of TGF-beta1 and PDGF-BB in VCG were significantly higher, while those in QSG were significantly lower than those in VCG (P < 0.01).

CONCLUSION

Adenovirus infection can increase the protein expression of TGF-beta1 and PDGF-BB of human embryonic lung fibroblast cells. QOL can decrease the protein expression of these cytokines, which maybe one of the mechanisms of its antiviral effect.

Nested multiplex PCR assay for detection of human enteric viruses in shellfish and sewage

Environmental samples and contaminated shellfish present frequently low concentrations of more than one viral species. For this reason, a nested multiplex RT-PCR was developed for the detection of adenoviruses, enteroviruses and hepatitis A viruses in different environmental samples such as urban sewage and shellfish. This assay will save time and cost for detection of these enteric viruses with a smaller sample volume, which otherwise can be a limiting factor in routine analysis. The limit of detection was approximately 1 copy for adenovirus and 10 copies for enterovirus and hepatitis A virus per PCR reaction using titrated cell-cultured viruses as template material. In shellfish and environmental samples, this multiplex PCR was optimized to detect all three viruses simultaneously when the concentration of each virus was equal or lower than 1000 copies per PCR reaction. This is the level found predominantly in the environment and in shellfish when the numbers of fecal bacterial and phage indicators are low. The detection of human adenoviruses by PCR has been suggested as a molecular index of fecal contamination of human origin in the environment and food and the multiplex assay developed may be a tool for evaluating the presence of viral contamination in shellfish and water and to expand microbiological control to include viral markers.

Novel short-term effects of adenovirus Ad-36 on hamster lipoproteins

OBJECTIVE

Human adenovirus Ad-36 induces adiposity and lowers total serum cholesterol in chickens, mice and marmosets and Ad-36 antibodies are associated with human obesity. We examined the early effects of Ad-36 inoculation on plasma cholesterol levels in hamsters fed a hyperlipidemic diet.

DESIGN

A total of 32 male Golden Syrian hamsters were divided into two equal weight-matched groups and intranasally inoculated with Ad-36 (INF: infected) or media (CON: control). In each group, the animals were fed either a purified diet (PF, n=8) 40%en fat +/-194 mg cholesterol/1000 kcal or chow (C, n=8) ad libitum. Animals were killed 5 weeks postinoculation.

RESULTS

Nested PCR assay detected Ad-36 DNA in the lung, liver, visceral adipose tissue and skeletal muscle of the INF group, but not in the CON animals. Ad-36 antibodies were detected in the INF group only. For all animals, total plasma cholesterol (TC) was not significantly affected by Ad-36 treatment (203+/-92 vs 193+/-75 mg/dl, P=NS; INF vs CON, respectively). In 5 weeks, Ad-36 infection had no effect on TC concentration in hamsters fed chow (128+/-39 vs 130+/-27 mg/dl, INF-C vs CON-C, respectively) or those fed PF (269+/-70 vs 256+/-47 mg/dl, INF-P vs CON-P, respectively). However, lipoproteins isolated by density gradient ultracentrifugation showed a greater proportion of LDL cholesterol in INF animals, as compared to CON (28.4+/-1.6% vs 16.4+/-1.2%, P=0.02), regardless of dietary treatment (INF-P vs CON-P: 27.3+/-2.1 vs 15.7+/-1.5%, P=0.07; and INF-C vs CON-C: 29.4+/-1.2 vs 17.0+/-1.1%, P=0.009). This shift appears to be from HDL cholesterol to the LDL fractions.

CONCLUSION

These data suggest that in the hamster (a model resembling several aspects of human lipoprotein metabolism), Ad-36 infection may acutely affect the intravascular processing of lipoproteins resulting in a more atherogenic lipoprotein profile.

A two decade survey of respiratory adenovirus in Taiwan: the reemergence of adenovirus types 7 and 4

From November 1999 to December 2001, three outbreaks of adenovirus (Ad) respiratory infection occurred in southern Taiwan. To determine the circulating serotypes and molecular epidemiology, a total of 524 virus strains were randomly selected from 1,064 strains isolated from 1981 to 2001, and were studied using restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR)-RFLP. The major subgenus found was subgenus B (45%), followed by subgenus E (29%) and subgenus C (25%). Ad3 and Ad7 were the major types found during the 1st outbreak, which occurred from November 1999 to March 2000, while Ad4 was found mainly during the 2nd and 3rd outbreaks in October 2000 and September 2001, respectively. Both Ad7 and Ad4 were reemerged serotypes, whereas Ad3 was consistently isolated during the survey, although it declined drastically from 36 to 2% in 2001. Genotype analysis in this study showed that the only strain of Ad7 found in 1983 was Ad7a, but all randomly selected strains of Ad7 isolated during 1999-2000 were Ad7b. The clinical features of 217 patients were analyzed during the 1999-2000 outbreaks. About 79% of the total cases were less than 7 years old. The ratio of male to female was 2:1. Severe infections, such as pneumonia and acute bronchitis, accounted for nearly half of the cases (43%). These results show the reemergence and changing of serotypes, the clinical association of respiratory adenovirus infections, and the molecular epidemiology of Ad7 genotypes in Taiwan during the past two decades.

Evaluation of R-Mix shell vials for the diagnosis of viral respiratory tract infections

Respiratory viruses cause significant morbidity and mortality. The management of these infections can be improved by a rapid diagnosis and administration of available virus-specific therapy. The goal of this study was to compare R-Mix, an engineered tissue monolayer for rapid shell vial (SV) diagnosis of viral respiratory infections, with conventional tissue culture (TC) and conventional respiratory SV (primary rhesus monkey kidney (RhMK) and Hep2 monolayers). The primary outcome measure was sensitivity for detection of influenza A and B, respiratory syncytial virus, parainfluenza 1-3, and adenovirus. The study was performed in two phases: (1) the three methods were compared using 250 nasal washes from children with lower respiratory tract infections; (2) a modified R-Mix SV harvesting schedule (SV were harvested at 24 and 120 h) was compared with TC and conventional RhMK/Hep2 SV using 311 respiratory specimens. A total of 110 viruses were identified in the first and 55 in the second phase. Diagnostic accuracies of R-Mix harvested at 24, 48, and 120 h were 98%, whereas for TC varied between 99 and 100%, and for RhMK/Hep2 SV between 98 and 99%. Sensitivities of R-Mix harvested at 24, 48, and 120 h were 26, 75, and 47%, respectively, whereas for TC varied between 60 and 94%, and for RhMK/Hep2 SV between 62 and 85%. R-Mix harvested at 48 h represent a valuable substitute for RhMK/Hep2 SV because they have comparable sensitivities and diagnostic accuracies, but R-Mix offers several technical advantages. In contrast, R-Mix harvested at 24h did not seem a very useful diagnostic tool. The utility of R-Mix harvested at 120 h, which accelerated the diagnosis of 16% of positive specimens in study phase 2, needs further investigation.

Unique physicochemical properties of human enteric Ad41 responsible for its survival and replication in the gastrointestinal tract

Human enteric adenovirus Ad41 is associated with children gastroenteritis. To infect gastrointestinal cells, the invading virus must be acid-stable and resistant to inactivation by bile salts and proteases. In addition, it has to cross the mucus barrier before it infects mucosa cells. We show that Ad41 infectivity is not diminished by acid exposure, a condition limiting the infectivity of the respiratory Ad. This feature can be attributed to a large extent to the global basic charge of enteric Ad virions and to the stability of Ad41 fiber, a viral protein mediating virus attachment. Upon exposure to pH shock, the respiratory Ad2 loses its ability to interact with lipids while enteric Ad41 still binds to the major phospholipids of gastric and intestine mucus. In addition, contrary to respiratory Ad, enteric Ad41 interacts with several sphingolipid components of plasma membranes. These results show that the molecular bases of the Ad41 enteric tropism stem from its particular physicochemical properties.

Thermal inactivation of adenovirus type 5

Adenovirus-based products are being developed for human use as vaccine constructs and gene therapy vehicles. In order to operate by cGMP guidelines and to address biosafety concerns, it is imperative to ensure that adequate decontamination procedures are implemented in adenovirus manufacturing facilities. Liquid decontamination procedures based on heat treatment are relatively easy to employ in a manufacturing setting. In this study, we have conducted small-scale experiments to determine the effectiveness of thermal inactivation procedures on adenovirus type 5. We have determined the robustness of the assays used to measure sample potency with regard to different sample matrices and adenovirus constructs. Greater than eight logs of reduction in adenovirus type 5 potency may be obtained upon exposure of the sample to temperatures greater than 70 degrees C and times longer than 20 min.

Effect of Ribavirin on the Plasma Viral DNA Load in Patients with Disseminating Adenovirus Infection

Adenovirus (AdV) infections are an increasingly frequent and potentially fatal complication in allogeneic stem cell transplant recipients. To determine the antiviral potential of ribavirin in an unbiased way, 4 patients without immune recovery were prospectively analyzed by quantitative measurement of plasma AdV DNA load. Administration of ribavirin at the first signs of AdV dissemination was not accompanied by a decrease in the plasma AdV DNA load in any of these patients, and an increase in the AdV load was even documented in 3. These observations question the potential of ribavirin to improve the outcome for patients with disseminating AdV infection and support a critical evaluation of antiviral treatments for AdV infection that involves the kinetics of virus DNA load as an objective parameter of viral replication.

Analyses of melanoma-targeted oncolytic adenoviruses with tyrosinase enhancer/promoter-driven E1A, E4, or both in submerged cells and organotypic cultures

We have generated novel conditionally replicative adenoviruses (CRAds) targeted to melanoma cells. In these adenoviruses, the E4 region (AdDelta24TyrE4) or both E1 and E4 regions (Ad2xTyr) were controlled by a synthetic tyrosinase enhancer/promoter (Tyr2E/P) specific for melanocytes. The properties of these CRAds were compared with wild-type adenovirus (Adwt) and our previous CRAd with a targeted E1A CRII mutation (AdTyrDelta24) in submerged cultures of melanoma cells and nonmelanoma control cells. We showed that AdDelta24TyrE4 had a cell type selectivity similar to AdTyrDelta24 but had a distinct block in viral reproduction in nonmelanoma cells and that Ad2xTyr had an augmented selectivity for melanoma cells. These viruses were additionally tested in organotypic cultures of melanoma cell lines, primary human keratinocytes (PHKs), or mixed cell populations. Unexpectedly, the CRAds exhibited somewhat different cell type selectivity profiles in these cultures relative to those observed in submerged cultures, demonstrating the importance of multiple assay systems. Specifically, AdTyrDelta24 and Ad2xTyr were selective for melanoma cells, whereas AdDelta24TyrE4 exhibited no selectivity, similar to Adwt. AdTyrDelta24 and Ad2xTyr were strongly attenuated in their ability to lyse PHKs in organotypic cultures. Furthermore, Ad2xTyr had a superior melanoma selectivity in organotypic cultures of cocultivated melanoma cells and PHKs. The enhanced selectivity for melanoma cells exhibited by Ad2xTyr provides a window of opportunity for therapeutic application. These studies also demonstrate that organotypic cultures derived from mixtures of tumor and normal cells represent a promising new model for analysis of CRAd specificity and toxicity.