Research and application of the SARS-CoV-2 vaccine based on adenovirus vector technology platform / 中华预防医学杂志

During the global efforts to prevent and control the COVID-19 pandemic, extensive research and development of SARS-CoV-2 vaccines using various technical approaches have taken place. Among these, vaccines based on adenovirus vector have gained substantial knowledge and experience in effectively combating potential emerging infectious diseases, while also providing novel ideas and methodologies for vaccine research and development (R&D). This comprehensive review focuses on the adenovirus vector technology platform in vaccine R&D, emphasizing the importance of mucosal immunity induced by adenoviral vector-based vaccine for COVID-19 prevention. Furthermore, it analyzes the key technical challenges and obstacles encountered in the development of vaccines based on the adenovirus vector technology platform, with the aim of providing valuable insights and references for researchers and professionals in related fields.

Effects of P311 on the angiogenesis ability of human microvascular endothelial cell 1 in vitro and its molecular mechanism / 中华烧伤杂志

Objective: To explore the effects of P311 on the angiogenesis ability of human microvascular endothelial cell 1 (HMEC-1) in vitro and the potential molecular mechanism. Methods: The experimental research method was used. HMEC-1 was collected and divided into P311 adenovirus group and empty adenovirus group according to the random number table (the same grouping method below), which were transfected correspondingly for 48 h. The cell proliferation activity was detected using the cell counting kit 8 on 1, 3, and 5 days of culture. The residual scratch area of cells at post scratch hour 6 and 11 was detected by scratch test, and the percentage of the residual scratch area was calculated. The blood vessel formation of cells at 8 h of culture was observed by angiogenesis experiment in vitro, and the number of nodes and total length of the tubular structure were measured. The protein expressions of vascular endothelial growth factor receptor 2 (VEGFR2), phosphorylated VEGFR2 (p-VEGFR2), extracellular signal-regulated kinase 1/2 (ERK1/2), and phosphorylated ERK1/2 (p-ERK1/2) in cells were detected by Western blotting. HMEC-1 was collected and divided into P311 adenovirus+small interfering RNA (siRNA) negative control group, empty adenovirus+siRNA negative control group, P311 adenovirus+siRNA-VEGFR2 group, and empty adenovirus+siRNA-VEGFG2 group, which were treated correspondingly. The protein expressions of VEGFR2, p-VEGFR2, ERK1/2, and p-ERK1/2 in cells were detected by Western blotting at 24 h of transfection. The blood vessel formation of cells at 24 h of transfection was observed by angiogenesis experiment in vitro, and the number of nodes and total length of the tubular structure were measured. HMEC-1 was collected and divided into P311 adenovirus+dimethylsulfoxide (DMSO) group, empty adenovirus+DMSO group, P311 adenovirus+ERK1/2 inhibitor group, and empty adenovirus+ERK1/2 inhibitor group, which were treated correspondingly. The protein expressions of ERK1/2 and p-ERK1/2 in cells were detected by Western blotting at 2 h of treatment. The blood vessel formation of cells at 2 h of treatment was observed by angiogenesis experiment in vitro, and the number of nodes and total length of the tubular structure were measured. The sample number at each time point in each group was 6. Data were statistically analyzed with independent sample t test, analysis of variance for repeated measurement, one-way analysis of variance, and least significant difference test. Results: Compared with that of empty adenovirus group, the proliferation activity of cells in P311 adenovirus group did not show significant difference on 1, 3, and 5 days of culture (with t values of -0.23, -1.30, and -1.52, respectively, P>0.05). The residual scratch area percentages of cells in P311 adenovirus group were significantly reduced at post scratch hour 6 and 11 compared with those of empty adenovirus group (with t values of -2.47 and -2.62, respectively, P<0.05). At 8 h of culture, compared with those of empty adenovirus group, the number of nodes and total length of the tubular structure of cells in P311 adenovirus group were significantly increased (with t values of 4.49 and 4.78, respectively, P<0.01). At 48 h of transfection, compared with those of empty adenovirus group, the protein expressions of VEGFR2 and ERK1/2 of cells in P311 adenovirus group showed no obvious changes (P>0.05), and the protein expressions of p-VEGFR2 and p-ERK1/2 of cells in P311 adenovirus group were significantly increased (with t values of 17.27 and 16.08, P<0.01). At 24 h of transfection, the protein expressions of p-VEGFR2 and p-ERK1/2 of cells in P311 adenovirus+siRNA negative control group were significantly higher than those in empty adenovirus+siRNA negative control group (P<0.01). The protein expressions of VEGFR2, p-VEGFR2, and p-ERK1/2 of cells in P311 adenovirus+siRNA negative control group were significantly higher than those in P311 adenovirus+siRNA-VEGFR2 group (P<0.01). The protein expressions of VEGFR2 and p-ERK1/2 of cells in empty adenovirus+siRNA negative control group were significantly higher than those in empty adenovirus+siRNA-VEGFR2 group (P<0.05 or P<0.01). At 24 h of transfection, the number of nodes of the tubular structure in cells of P311 adenovirus+siRNA negative control group was 720±62, which was significantly more than 428±38 in empty adenovirus+siRNA negative control group and 364±57 in P311 adenovirus+siRNA-VEGFR2 group (with P values both <0.01). The total length of the tubular structure of cells in P311 adenovirus+siRNA negative control group was (21 241±1 139) μm, which was significantly longer than (17 005±1 156) μm in empty adenovirus+siRNA negative control group and (13 494±2 465) μm in P311 adenovirus+siRNA-VEGFR2 group (with P values both <0.01). The number of nodes of the tubular structure in cells of empty adenovirus+siRNA negative control group was significantly more than 310±75 in empty adenovirus+siRNA-VEGFR2 group (P<0.01), and the total length of the tubular structure of cells in empty adenovirus+siRNA negative control group was significantly longer than (11 600±2 776) μm in empty adenovirus+siRNA-VEGFR2 group (P<0.01). At 2 h of treatment, the protein expression of p-ERK1/2 of cells in P311 adenovirus+DMSO group was significantly higher than that in empty adenovirus+DMSO group and P311 adenovirus+ERK1/2 inhibitor group (with P values both <0.01), and the protein expression of p-ERK1/2 of cells in empty adenovirus+DMSO group was significantly higher than that in empty adenovirus+ERK1/2 inhibitor group (P<0.05). At 2 h of treatment, the number of nodes of the tubular structure in cells of P311 adenovirus+DMSO group was 726±72, which was significantly more than 421±39 in empty adenovirus+DMSO group and 365±41 in P311 adenovirus+ERK1/2 inhibitor group (with P values both <0.01). The total length of the tubular structure of cells in P311 adenovirus+DMSO group was (20 318±1 433) μm, which was significantly longer than (16 846±1 464) μm in empty adenovirus+DMSO group and (15 114±1 950) μm in P311 adenovirus+ERK1/2 inhibitor group (with P values both <0.01). The number of nodes of the tubular structure in cells of empty adenovirus+DMSO group was significantly more than 317±67 in empty adenovirus+ERK1/2 inhibitor group (P<0.01), and the total length of the tubular structure of cells in empty adenovirus+DMSO group was significantly longer than (13 188±2 306) μm in empty adenovirus+ERK1/2 inhibitor group (P<0.01). Conclusions: P311 can enhance the angiogenesis ability of HMEC-1 by activating the VEGFR2/ERK1/2 signaling pathway.

Construction of recombinant adenovirus expressing capsid protein of serotype O foot-and-mouth disease virus and analysis of its immunogenicity / 生物工程学报

In order to construct a recombinant replication deficient human type 5 adenovirus (Ad5) expressing a foot-and-mouth disease virus (FMDV) capsid protein, specific primers for P12A and 3B3C genes of FMDV-OZK93 were synthesized. The P12A and 3B3C genes were then amplified and connected by fusion PCR, and a recombinant shuttle plasmid pDC316-mCMV-EGFP-P12A3B3C expressing the FMDV-OZK93 capsid protein precursor P12A and 3B3C protease were obtained by inserting the P12A3B3C gene into the pDC316-mCMV-EGFP plasmid. The recombinant adenovirus rAdv-P12A3B3C-OZK93 was subsequently packaged, characterized and amplified using AdMaxTM adenovirus packaging system, and the expression was verified by infecting human embryonic kidney cell HEK-293. The humoral and cellular immunity levels of well-expressed and purified recombinant adenovirus immunized mice were evaluated. The results showed that rAdv-P12A3B3C-OZK93 could be stably passaged and the maximum virus titer reached 1×109.1 TCID50/mL. Western blotting and indirect immunofluorescence showed that rAdv-P12A3B3C-OZK93 expressed the FMDV-specific proteins P12A and VP1 in HEK-293 cells. In addition, the PK cell infection experiment confirmed that rAdv-P12A3B3C-OZK93 could infect porcine cells, which is essential for vaccination in pigs. Comparing with the inactivated vaccine group, the recombinant adenovirus could induce higher FMDV-specific IgG antibodies, γ-IFN and IL-10. This indicates that the recombinant adenovirus has good immunity for animal, which is very important for the subsequent development of foot-and-mouth disease vaccine.

Preparation and characterization of Ad-ERα-36-Fc-GFP / 生物工程学报

ERα-36 is a novel subtype of estrogen receptor α which promotes tumor cell proliferation, invasion and drug resistance, and it serves as a therapeutic target. However, only small-molecule compounds targeting ERα-36 are under development as anticancer drugs at present. Gene therapy approach targeting ERα-36 can be explored using recombinant adenovirus armed with decoy receptor. The recombinant shuttle plasmid pDC316-Ig κ-ERα-36-Fc-GFP was constructed via genetic engineering to express an Ig κ-signaling peptide-leading secretory recombinant fusion protein ERα-36-Fc. The recombinant adenovirus Ad-ERα-36-Fc-GFP was subsequently packaged, characterized and amplified using AdMaxTM adenovirus packaging system. The expression of fusion protein and functional outcome of Ad-ERα-36-Fc-GFP transduction were further analyzed with triple-negative breast cancer MDA-MB-231 cells. Results showed that the recombinant adenovirus Ad-ERα-36-Fc-GFP was successfully generated. The virus effectively infected MDA-MB-231 cells which resulted in expression and secretion of the recombinant fusion protein ERα-36-Fc, leading to significant inhibition of EGFR/ERK signaling pathway. Preparation of the recombinant adenovirus Ad-ERα-36-Fc-GFP provides a basis for further investigation on cancer gene therapy targeting ERα-36.

Construction and identification of recombinant adenovirus vector and observation of its transfecting rabbit bone marrow mesenchymal stem cells / 中国骨伤

OBJECTIVE@#To construct and identify adenovirus vector co-expressing hBMP2 and hVEGF165 fusion protein which labeled with green fluorescence protein, and laying the foundtion of the effect of hBMP2 and hVEGF165 gene inducing BMMSCs differentiation to osteoblast and bone defect repaired in the body.@*METHODS@#BMP2 and VEGF165 gene was amplified from cDNA library by PCR and inserted to the polyclonal site of adenovirus shuttle plasmid pAd-MCMV-GFP. Ad-BMP2- VEGF165 was recombinated and propagated in HEK293 cells by co-transfecting with the constructed recombinant shuttle plasmid pAd-MCMV-BMP2-VEGF165 and adenovirus helper plasmid pBHGloxΔ E1, 3Cre. The recombinant adenovirus was purified and virustiter was determined, and then to research GFP expression and to calculate the adenovirus transfection rate in rabbit BMMSCs.@*RESULTS@#The recombinant adenovirus vector Ad-BMP2-VEGF165 was successfully constructed by the methods of gene analyzing, colony PCR, Western blotting and observing GFP expression, and the titer of the adenovirus was 1×10@*CONCLUSION@#Recombinant adenovirus vector containing hBMP2 and hVEGF165 gene was successfully constructed and its high titer was obtained.

Improving adenoviral vectors and strategies for prostate cancer gene therapy

Gene therapy has been evaluated for the treatment of prostate cancer and includes the application of adenoviral vectors encoding a suicide gene or oncolytic adenoviruses that may be armed with a functional transgene. In parallel, versions of adenoviral vector expressing the p53 gene (Ad-p53) have been tested as treatments for head and neck squamous cell carcinoma and non-small cell lung cancer. Although Ad-p53 gene therapy has yielded some interesting results when applied to prostate cancer, it has not been widely explored, perhaps due to current limitations of the approach. To achieve better functionality, improvements in the gene transfer system and the therapeutic regimen may be required. We have developed adenoviral vectors whose transgene expression is controlled by a p53-responsive promoter, which creates a positive feedback mechanism when used to drive the expression of p53. Together with improvements that permit efficient transduction, this new approach was more effective than the use of traditional versions of Ad-p53 in killing prostate cancer cell lines and inhibiting tumor progression. Even so, gene therapy is not expected to replace traditional chemotherapy but should complement the standard of care. In fact, chemotherapy has been shown to assist in viral transduction and transgene expression. The cooperation between gene therapy and chemotherapy is expected to effectively kill tumor cells while permitting the use of reduced chemotherapy drug concentrations and, thus, lowering side effects. Therefore, the combination of gene therapy and chemotherapy may prove essential for the success of both approaches.

Molecular identification of viral agents associated with acute conjunctivitis: a prospective controlled study

Abstract Background: Viral conjunctivitis are the most frequent infections in ophthalmology clinics. The diagnosis is usually relying on clinical findings and medical history. However, topical antibiotics are often used unnecessarily addition to symptomatic treatment because of unsure agents. We aimed to detect the Adenovirus, Coxsackievirus and Enterovirus from conjunctiva and pharyngeal samples of patients. Methods: The conjunctiva and pharyngeal samples of the patients with conjunctivitis were taken by Virocult transport media and kept at -80 ºC up to study day. Adenovirus spp, Enterovirus 70 and Enterovirus 71, Coxsackie A24 and Coxsackie A16 were detected by real-time PCR. Samples from healthy health care workers of ophthalmology clinic were used for control group. Results: A total of 176 samples (conjunctival and pharyngeal samples of 62 patient and 26 healthy subjects) were included. The mean age of 34 (55.7%) male and 27 (44.3%) female patients was 34 ± 17. Twenty five (40.3%) of the patients were receiving antibiotic drops at first visit. The main etiologic agent in conjunctival samples was found to be Adenovirus (46/62, 74.2%) followed by Enterovirus 70 (4/62, 6.4%) and Enterovirus 71 (4/62, 6.4%). Coxsackievirus 16 and 24 were also found in 2 patients (1/62 each, 1.6%). Pharyngeal samples were also positive for Adenovirus (20/62, 32.3%), Enterovirus 70 and 71 (7/62, 11.3% and 5/62, 8.1% respectively), Coxsackievirus 16 and 24 (2/62, 3.2% and 1/61, 1.6%). Conclusions: It is very difficult in viral conjunctivitis to make clinical differentiation caused by different agents because of common clinical signs and symptoms. In routine clinical work, the viral conjunctivitis usually related with Adenovirus. But almost one fourth of the patients' conjunctivitis were not related to Adenovirus, which shows the importance of the laboratory diagnostics. True diagnosis plays an important role on prevention of contamination and unnecessary use of antibiotics in viral conjunctivitis.

A non-enteric adenovirus A12 gastroenteritis outbreak in Rio de Janeiro, Brazil

A gastroenteritis outbreak that occurred in 2013 in a low-income community in Rio de Janeiro was investigated for the presence of enteric viruses, including species A rotavirus (RVA), norovirus (NoV), astrovirus (HAstV), bocavirus (HBoV), aichivirus (AiV), and adenovirus (HAdV). Five of nine stool samples (83%) from patients were positive for HAdV, and no other enteric viruses were detected. Polymerase chain reaction products were sequenced and subjected to phylogenetic analysis, which revealed four strains and one strain of non-enteric HAdV-A12 and HAdV-F41, respectively. The HAdV-A12 nucleotide sequences shared 100% nucleotide similarity. Viral load was assessed using a TaqMan real-time PCR assay. Stool samples that were positive for HAdV-A12 had high viral loads (mean 1.9 X 107 DNA copies/g stool). All four patients with HAdV-A12 were < 25 months of age and had symptoms of fever and diarrhoea. Evaluation of enteric virus outbreaks allows the characterisation of novel or unique diarrhoea-associated viruses in regions where RVA vaccination is routinely performed.

Promoting inflammatory lymphangiogenesis by vascular endothelial growth factor-C (VEGF-C) aggravated intestinal inflammation in mice with experimental acute colitis

Angiogenesis and lymphangiogenesis are thought to play a role in the pathogenesis of inflammatory bowel diseases (IBD). However, it is not understood if inflammatory lymphangiogenesis is a pathological consequence or a productive attempt to resolve the inflammation. This study investigated the effect of lymphangiogenesis on intestinal inflammation by overexpressing a lymphangiogenesis factor, vascular endothelial growth factor-C (VEGF-C), in a mouse model of acute colitis. Forty eight-week-old female C57BL/6 mice were treated with recombinant adenovirus overexpressing VEGF-C or with recombinant VEGF-C156S protein. Acute colitis was then established by exposing the mice to 5% dextran sodium sulfate (DSS) for 7 days. Mice were evaluated for disease activity index (DAI), colonic inflammatory changes, colon edema, microvessel density, lymphatic vessel density (LVD), and VEGFR-3mRNA expression in colon tissue. When acute colitis was induced in mice overexpressing VEGF-C, there was a significant increase in colonic epithelial damage, inflammatory edema, microvessel density, and neutrophil infiltration compared to control mice. These mice also exhibited increased lymphatic vessel density (73.0±3.9 vs 38.2±1.9, P<0.001) and lymphatic vessel size (1974.6±104.3 vs 1639.0±91.5, P<0.001) compared to control mice. Additionally, the expression of VEGFR-3 mRNA was significantly upregulated in VEGF-C156S mice compared to DSS-treated mice after induction of colitis (42.0±1.4 vs 3.5±0.4, P<0.001). Stimulation of lymphangiogenesis by VEGF-C during acute colitis promoted inflammatory lymphangiogenesis in the colon and aggravated intestinal inflammation. Inflammatory lymphangiogenesis may have pleiotropic effects at different stages of IBD.

The prevalence of adenoviral conjunctivitis at the Clinical Hospital of the State University of Campinas, Brazil

OBJECTIVES: Viral conjunctivitis is a common, highly contagious disease that is often caused by an adenovirus. The aim of this study was to evaluate the prevalence of adenoviral conjunctivitis by analyzing data from a prospective clinical study of 122 consecutively enrolled patients who were treated at the Clinical Hospital of the State University of Campinas (UNICAMP) after a clinical diagnosis of infectious conjunctivitis between November 2011 and June 2012. METHODS: Polymerase chain reaction was used to evaluate all cases of clinically diagnosed infectious conjunctivitis and based on the laboratory findings, the prevalence of adenoviral infections was determined. The incidence of subepithelial corneal infiltrates was also investigated. RESULTS: Of the 122 patients with acute infectious conjunctivitis included, 72 had positive polymerase chain reaction results for adenoviruses and 17 patients developed subepithelial corneal infiltrates (13.93%). CONCLUSIONS: The polymerase chain reaction revealed that the prevalence of adenoviral conjunctivitis was 59% in all patients who presented with a clinical diagnosis of infectious conjunctivitis from November 2011 to June 2012. The prevalence of adenoviral conjunctivitis in the study population was similar to its prevalence in other regions of the world.

Adenoviruses of canine and human origins in stool samples from free-living pampas foxes (Lycalopex gymnocercus) and crab-eating foxes (Cerdocyon thous) in São Francisco de Paula, Rio dos Sinos basin / Adenovírus de origens canina e humana em fezes de graxains (Lycalopex gymnocercus) e cachorros-do-mato (Cerdocyon thous) de vida livre em São Francisco de Paula, bacia do Rio dos Sinos

The spread of enteric viruses of domestic animals and human beings to wild species can be facilitated by the resistance of these viruses on the environment and their ability to be transmitted by water and contaminated food. The health status of the populations of pampas foxes (Lycalopex gymnocercus) and crab-eating foxes (Cerdocyon thous) is largely unknown and the landscapes occupied by these animals in southern Brazil have been threatened by human occupation and expansion of agriculture. In this work, the search of genomes of human and canine adenoviruses in feces from these wild carnivores was used to track the dissemination of domestic animals and human pathogens to the free-living populations in a wildlife reserve located in southern Brazil. This was performed by virus-specific differential real-time polymerase chain reactions (qPCR) on stool specimens, avoiding capture and additional stress to the animals. Genus-specific conventional reverse-transcriptase PCR (RT-PCR) was complementarily performed aiming the detection of enteroviruses (EV) and rotaviruses (RV) on these same samples. HAdV genomes were found on 14 out of the 17 (82.35%) stool samples analysed, whereas CAV was found co-infecting 5 of these samples. RV genomes were detected on 7 of the 17 samples (41.18%) and all samples were negative for EV. The results point to the dispersion of HAdV and RV at a high rate to these species of South American wild carnivores, which can be an effect of growing anthropisation of the habitat of these animals.

A disseminação de vírus entéricos de animais domésticos e seres humanos para espécies selvagens pode ser facilitada pela resistência desses vírus no ambiente e sua capacidade de ser transmitida por água e alimentos contaminados. O estado de saúde das populações de Graxains-do-campo (Lycalopex gymnocercus) e Cachorros-do-mato (Cerdocyon thous) é em grande parte desconhecida e as paisagens ocupadas por estes animais no sul do Brasil têm sido ameaçadas pela ocupação humana e a expansão da agricultura. Neste trabalho, utilizou-se a pesquisa de genomas de adenovírus humanos (HAdV ) e caninos (CAV-1 e -2) em amostras fezes desses carnívoros selvagens com vistas a diagnosticar a disseminação de patógenos de animais domésticos e seres humanos às populações de vida livre em uma reserva de vida selvagem, localizado no sul do Brasil. Foram realizadas reações em cadeia da polimerase diferenciais e em tempo real (qPCR) de adenovírus específicos em amostras de fezes, evitando a captura e estresse adicional para os animais. PCRs gênero-específicas convencionais com transcrição reversa prévia (RT-PCR) foram ainda realizadas visando a detecção de enterovírus (EV) e rotavírus (RV) nestas mesmas amostras. Genomas de HAdV foram encontrados em 14 a 17 amostras de fezes (82.35%) analisados, Considerando que o CAV foi encontrado coinfectando 5 destas amostras. Genomas de RV foram detectados em 7 das 17 amostras (41.18%) e todas as amostras foram negativas para EV. Os resultados apontam para a dispersão de HAdV e RV em uma taxa elevada para estas espécies de carnívoros selvagens sul-americanas, que podem ser um efeito da crescente antropização do habitat desses animais.

Detección de norovirus en niños con diarrea adquirida en la comunidad o nosocomial en el Hospital Guillermo Grant Benavente de Concepción, Chile / Norovirus detection in children with community-acquired or nosocomial diarrhea at Guillermo Grant Benavente Hospital in Concepción, Chile

Introduction: Norovirus (NoV) are RNA viruses highly contagious, stable in the environment, genetically variable, and the most common cause of viral sporadic acute gastroenteritis worldwide. This is the first study carried out in Concepcion, Chile, to investigate the presence of NoV as an etiologic agent of viral diarrheas in hospitalized children. Objective. To detect the presence and genogroup of NoV in children with diarrhea and to compare it with rotavirus (RV) and adenovirus (AdV). Material and Methods: A one year descriptive, prospective study in children 0-14 years old. A single diarrheic stool sample per patient was analyzed for the presence of NoV, RV and AdV. Clinical data were unknown at the moment of sampling. Real time RT-PCR with Taqman™ probes for NoV and the immunocromatography VIKIA™ kit for RoV /AV detection were used. Results: Infection for NoV (25.5%) was significantly higher than for RV (15.9%) and AdV (6.2%). It was even greater in infants younger than 2yr. old (n: 103): NoV 34%, RV 17.5%, AdV 7.8%. Children 2-4 yr. old had 11.8% infection of NoV and RV. Children older than 4, only had 12% RV and 4% AdV. Children hospitalized for diarrhea (n: 92) had: 21.7% of both NoV and RV, and 7.6% AdV; whereas children hospitalized for other causes (n: 53) had 32.1% NoV,5.7% RV and 3.8% AV. The proportion of infection due to NoV was significantly higher in males (31.5%) than in females (19.4%). The average frequency during the year was higher for NoV (30.3%) than for RV (14.7%) except in summer. Conclusion: The presence of NoV was higher than RV in children with diarrhea. NoV infection showed defined characteristics regarding age, gender, seasonal occurrence and nosocomial transmission that are important epidemiological features.

Introducción: Los norovirus (NoV) son virus ARN altamente contagiosos, resistentes, variables genéticamente y una de las etiologías más frecuente de gastroenteritis viral esporádica mundial. Este es el primer trabajo en Concepción, Chile, de búsqueda de NoV como etiología viral de diarreas en niños hospitalizados. Objetivo: Determinar la presencia y genogrupo de NoV en niños con diarrea y compararla con la frecuencia de rotavirus (RV) y adenovirus (AdV). Material y Método: Estudio descriptivo, prospectivo de un año, en niños de 0-14 años ingresados por diarrea aguda o que la adquirieron dentro del hospital. La muestra de deposiciones diarreica se tomó una sola vez por paciente. Las fichas clínicas se analizaron al finalizar el estudio etiológico. Para la detección de NoV se utilizó RPC-TR a en tiempo real con sondas Taqman® y para detección de RV/AdV, el kit VIKIA® de inmunocromatografia. Resultados: La infección por NoV (25,5%) fue significativamente más frecuente que por RV (15,9%) y AdV (6,2%). La mayor presencia de infección fue en pacientes bajo2 años de edad (n: 103): NoV 34,0%, RV 17,5%, AdV 7,8%. La detección en niños hospitalizados por diarrea fue: NoV y RV 21,7% cada uno; AdV 7,6%. En niños con diarrea nosocomial hospitalizados por otras causas se detectó NoV en 32,1%, RV en 5,7% y AdV en 3,8%. La presencia de NoV fue significativamente mayor en varones (31,5%) que en niñas (19,4%). El promedio de diarreas durante el año fue mayor para NoV (30,3%) que para RV(14,7%), excepto en verano. Discusión y Conclusión: La presencia de NoV fue mayor que la de RoV en niños con diarrea y con una tendencia nosocomial que podría deberse a las características del virus que favorece infecciones de ambiente confinado, como hospitales, asilos y cruceros. La infección por NoV presentó características definidas, en edad, género, ocurrencia estacional y relevancia nosocomial, que aportan datos epidemiológicos importantes.

A simple negative selection method to identify adenovirus recombinants using colony PCR

Background: The AdEasy system is a fast-track system for generating recombinant adenoviruses using the efficient homologous recombination machinery between shuttle and adenovirus backbone plasmids in Escherichia coli BJ5183 cells. The key step is homologous recombination in BJ5183 cells, which is driven by RecA activity. However, culture time is stringently limited to reduce the damage to recombinant plasmids by RecA activity. Therefore, rapid identification of recombinant adenoviruses within the limited time-period is critical. Results: We developed a simple negative selection method to identify recombinant adenoviruses using colony PCR, which improves the efficiency of adenovirus recombination screening and packaging. Conclusions: The negative selection method to identify AdEasy adenovirus recombinants by colony PCR can identify the recombined colony within a short time-period, and maximally avoid damage to the recombinant plasmid by limiting recombination time, resulting in improved adenovirus packaging.

Enhancing mucosal immunity in mice by recombinant adenovirus expressing major epitopes of porcine circovirus-2 capsid protein delivered with cytosine-phosphate-guanosine oligodeoxynucleotides

A recombinant replication-defective adenovirus expressing the major epitopes of porcine circovirus-2 (PCV-2) capsid protein (rAd/Cap/518) was previously constructed and shown to induce mucosal immunity in mice following intranasal delivery. In the present study, immune responses induced by intranasal immunization with a combination of rAd/Cap/518 and cytosine-phosphate-guanosine oligodeoxynucleotides (CpG ODN) were evaluated in mice. The levels of PCV-2-specific IgG in serum and IgA in saliva, lung, and intestinal fluids were significantly higher in the group immunized with rAd/Cap/518 and CpG ODN than animals immunized with rAd/Cap/518 alone. The frequencies of IL-2-secreting CD4+ T cells and IFN-gamma-producing CD8+ T cells were significantly higher in the combined immunization group than mice immunized with rAd/Cap/518 alone. The frequencies of CD3+, CD3+CD4+CD8-, and CD3+CD4-CD8+ T cells in the combined immunization group were similar to that treated with CpG ODN alone, but significantly higher than mice that did not receive CpG ODN. PCV-2 load after challenge in the combined immunization group was significantly lower than that in the phosphate-buffered saline placebo group and approximately 7-fold lower in the group treated with CpG ODN alone. These results indicate that rAd/Cap/518 combined with CpG ODN can enhance systemic and local mucosal immunity in mice, and represent a promising synergetic mucosal vaccine against PCV-2.

Evaluation of an Immunochromatographic Assay for the Rapid and Simultaneous Detection of Rotavirus and Adenovirus in Stool Samples

BACKGROUND: We evaluated the analytical and clinical performances of the SD BIOLINE Rota/Adeno Rapid kit (SD Rota/Adeno Rapid; Standard Diagnostics, Inc., Korea), an immunochromatographic assay (ICA), for the simultaneous detection of rotaviruses and adenoviruses in human stool samples. METHODS: We tested 400 clinical stool samples from patients with acute gastroenteritis and compared the ICA results with the results obtained by using ELISA, enzyme-linked fluorescent assays (ELFA), PCR, and multiplex reverse transcription-PCR (mRT-PCR). To assess the analytical performance of the SD BIOLINE Rota/Adeno Rapid kit, we determined its detection limit, reproducibility, cross-reactivity, and analytical reactivity for adenovirus subtypes, and performed interference studies. RESULTS: The overall agreement rates among the tested methods were 91.5% for rotavirus and 85.5% for adenovirus. On the basis of mRT-PCR, the overall agreement, positive agreement, and negative agreement rates of the ICA were 95.6%, 100%, and 94.9% for rotavirus, and 94.0%, 71.4%, and 94.8% for adenovirus, respectively. Using the ICA, we detected all the subtypes of adenovirus tested, but the analytical reactivities for adenovirus subtypes were different between the 4 adenovirus detection methods. The high reproducibility was confirmed, and no cross-reactivity or interference was detected. CONCLUSIONS: The SD BIOLINE Rota/Adeno Rapid kit showed acceptable analytical and clinical performances. However, interpretation of adenovirus positive/negative result should be cautious because of different detectability for adenovirus subtypes among adenovirus detection methods.

Gene Therapy Using Hepatocyte Growth Factor Expressing Adenovirus Improves Skin Flap Survival in a Rat Model

Hepatocyte growth factor (HGF) is a potent angiogenic factor that can stimulate the production of blood vessels in ischemic tissue. We investigated whether gene therapy using HGF-expressing adenovirus could enhance skin flap survival. Sprague-Dawley rats were randomly divided into three groups. Rats were subdermally injected with HGF-expressing adenovirus (HGF virus group), recombinant HGF (rhHGF group), or phosphate buffered saline (PBS group) 2 days before and immediately after 3 x 9 cm caudal flap elevation. The survival area of the skin flap, the ratio of blood flow, CD31-positive vessels and, VEGF expression were examined. Skin flap viability was significantly increased in the HGF virus group compared to the rhHGF and PBS groups (71.4% +/- 5.9%, 63.8%+/- 6.4%, and 39.2% +/- 13.0%, respectively) (P = 0.025). Furthermore, the blood flow ratio was significantly increased in the HGF virus group. In the HGF virus group, the number of CD31-positive vessels and vascular endothelial growth factor (VEGF) expression were significantly increased. Gene therapy using HGF-expressing adenovirus increase VEGF expression, the number of viable capillaries, and blood flow to the flap, thereby improving skin flap survival.

Osteogenesis induced in goat bone marrow progenitor cells by recombinant adenovirus coexpressing bone morphogenetic protein 2 and basic fibroblast growth factor

Bone morphogenetic protein 2 (BMP2) and basic fibroblast growth factor (bFGF) have been shown to exhibit a synergistic effect to promote bone repair and healing. In this study, we constructed a novel adenovirus with high coexpression of BMP2 and bFGF and evaluated its effect on osteogenic differentiation of goat bone marrow progenitor cells (BMPCs). Recombinant adenovirus Ad-BMP2-bFGF was constructed by using the T2A sequence. BMPCs were isolated from goats by density gradient centrifugation and adherent cell culture, and were then infected with Ad-BMP2-bFGF or Ad-BMP2. Expression of BMP2 and bFGF was detected by ELISA, and alkaline phosphatase (ALP) activity was detected by an ALP assay kit. In addition, von Kossa staining and immunocytochemical staining of collagen II were performed on BMPCs 21 days after infection. There was a high coexpression of BMP2 and bFGF in BMPCs infected with Ad-BMP2-bFGF. Twenty-one days after infection, ALP activity was significantly higher in BMPCs infected with Ad-BMP2-bFGF than in those infected with Ad-BMP2. Larger and more mineralized calcium nodules, as well as stronger collagen II staining, were observed in BMPCs infected with Ad-BMP2-bFGF than in those infected with Ad-BMP2. In summary, we developed a novel adenovirus vector Ad-BMP2-bFGF for simultaneous high coexpression of BMP2 and bFGF, which could induce BMPCs to differentiate efficiently into osteoblasts.

Adenovirus-mediated siRNA targeting TNF-α and overexpression of bone morphogenetic protein-2 promotes early osteoblast differentiation on a cell model of Ti particle-induced inflammatory response in vitro

Wear particles are phagocytosed by macrophages and other inflammatory cells, resulting in cellular activation and release of proinflammatory factors, which cause periprosthetic osteolysis and subsequent aseptic loosening, the most common causes of total joint arthroplasty failure. During this pathological process, tumor necrosis factor-alpha (TNF-α) plays an important role in wear-particle-induced osteolysis. In this study, recombination adenovirus (Ad) vectors carrying both target genes [TNF-α small interfering RNA (TNF-α-siRNA) and bone morphogenetic protein 2 (BMP-2)] were synthesized and transfected into RAW264.7 macrophages and pro-osteoblastic MC3T3-E1 cells, respectively. The target gene BMP-2, expressed on pro-osteoblastic MC3T3-E1 cells and silenced by the TNF-α gene on cells, was treated with titanium (Ti) particles that were assessed by real-time PCR and Western blot. We showed that recombinant adenovirus (Ad-siTNFα-BMP-2) can induce osteoblast differentiation when treated with conditioned medium (CM) containing RAW264.7 macrophages challenged with a combination of Ti particles and Ad-siTNFα-BMP-2 (Ti-ad CM) assessed by alkaline phosphatase activity. The receptor activator of nuclear factor-κB ligand was downregulated in pro-osteoblastic MC3T3-E1 cells treated with Ti-ad CM in comparison with conditioned medium of RAW264.7 macrophages challenged with Ti particles (Ti CM). We suggest that Ad-siTNFα-BMP-2 induced osteoblast differentiation and inhibited osteoclastogenesis on a cell model of a Ti particle-induced inflammatory response, which may provide a novel approach for the treatment of periprosthetic osteolysis.

Generation and Immunity Testing of a Recombinant Adenovirus Expressing NcSRS2-NcGRA7 Fusion Protein of Bovine Neospora caninum

Neospora caninum is the etiologic agent of bovine neosporosis, which affects the reproductive performance of cattle worldwide. The transmembrane protein, NcSRS2, and dense-granule protein, NcGRA7, were identified as protective antigens based on their ability to induce significant protective immune responses in murine neosporosis models. In the current study, NcSRS2 and NcGRA7 genes were spliced by overlap-extension PCR in a recombinant adenovirus termed Ad5-NcSRS2-NcGRA 7, expressing the NcSRS2-NcGRA7 gene, and the efficacy was evaluated in mice. The results showed that the titer of the recombinant adenovirus was 10(9)TCID50/ml. Three weeks post-boost immunization (w.p.b.i.), the IgG antibody titer in sera was as high as 1:4,096. IFN-gamma and IL-4 levels were significantly different from the control group (P<0.01). This research established a solid foundation for the development of a recombinant adenovirus vaccine against bovine N. caninum.

Respiratory Viral Infections after Hematopoietic Stem Cell Transplantation in Children

This study was performed to characterize respiratory viral infections in pediatric patients undergoing hematopoietic stem cell transplantation (HSCT). Study samples included 402 respiratory specimens obtained from 358 clinical episodes that occurred in the 116 children of the 175 consecutive HSCT cohort at Seoul National University Children's Hospital, Korea from 2007 to 2010. Multiplex reverse-transcription polymerase chain reactions were performed for rhinovirus, respiratory syncytial virus (RSV), parainfluenza viruses (PIVs), adenovirus, human coronavirus (hCoV), influenza viruses and human metapneumovirus. Viruses were identified in 89 clinical episodes that occurred in 58 patients. Among the 89 clinical episodes, frequently detected viruses were rhinovirus in 25 (28.1%), RSV in 23 (25.8%), PIV-3 in 16 (18.0%), adenovirus in 12 (13.5%), and hCoV in 10 (11.2%). Lower respiratory tract infections were diagnosed in 34 (38.2%). Neutropenia was present in 24 (27.0%) episodes and lymphopenia was in 31 (34.8%) episodes. Sixty-three percent of the clinical episodes were hospital-acquired. Three patients died of respiratory failure caused by respiratory viral infections. Respiratory viral infections in pediatric patients who have undergone HSCT are common and are frequently acquired during hospitalization. Continuous monitoring is required to determine the role of respiratory viruses in immunocompromised children and the importance of preventive strategies.