http://www.virologyj.com The latest research articles published by Virology Journal 2010-02-09T00:00:00Z This is an RSS newsfeed from BioMed Central It is intended to be used with an RSS reader. For more information about RSS newsfeeds from BioMed Central, visit http://www.biomedcentral.com/info/about/rss/ Background: Influenza is a respiratory disease that seriously threatens human health. In fact, influenza virus itself does not make critical contribution to mortality induced by influenza, but "cytokine storm" produced by the excessive immune response triggered by the virus can result in inflammatory reaction of lung tissues and fatal lung tissue injury, and thus increase influenza mortality. Therefore, besides antiviral drugs, immunosuppression drugs should also be included in infection treatment.Presentation of the hypothesisComplement is the center of inflammatory reaction. If complement system is over activated, the body will have strong inflammatory reaction or tissue injury, resulting in pathological process. Many studies have proved that, inflammatory injury of lung tissues caused by influenza virus is closely related to complement activation. Therefore, inhibiting complement activation can significantly reduce inflammatory injury in lung tissues. As complement is both a physiological defense and pathological damage medium, systematic inhibition may result in side effects including infection. Therefore, we design targeting complement inhibitors for complement activation sites, i.e. with CR2 as targeting vector, complement inhibitors like CD59 and Crry are targeted to inflammatory sites to specially inhibit the complement activation in local injury, thus local inflammatory reaction is inhibited.Testing the hypothesisCR2-CD59 and CR2-Crry targeting complement inhibitors are fusion-expressed, and their biological activity is examined via in vivo and in vitro tests. CR2 targeting complement inhibitors are used to treat mouse influenza viral pneumonia model, with PBS treatment group as the control. The survival and lung tissue injury of the mice is observed and the effect of CR2 targeting complement inhibitors on pneumonia induced by influenza virus is evaluated.Implications of the hypothesisCR2 targeting complement inhibitors are expected to be ideal drugs for viral pneumonia. http://www.virologyj.com/content/7/1/30 Chuanfu Zhang Yuanyong Xu Leili Jia Yutao Yang Yong Wang Yansong Sun Liuyu Huang Fei Qiao Stephen Tomlinson Xuelin Liu Yusen Zhou Hongbin Song Virology Journal 2010, 7:30 2010-02-09T00:00:00Z doi:10.1186/1743-422X-7-30 Virology Journal 1743-422X 7 30 2010-02-09T00:00:00Z PDF Background: Human astroviruses (HAstVs) are one of the important causes of acute gastroenteritis in children. Currently, eight HAstV genotypes have been identified and all but two (HAstV-6 and HAstV-7) have been fully sequenced. We here sequenced and analyzed the complete genome of a HAstV-6 strain (192-BJ07), which was identified in Beijing, China. Results: The genome of 192-BJ07 consists of 6745 nucleotides. The 192-BJ07 strain displays a 77.2-78.0% nucleotide sequence identity with other HAstV genotypes and exhibits amino acid sequence identities of 86.5-87.4%, 94.2-95.1%, and 65.5-74.8% in the ORF1a, ORF1b, and ORF2 regions, respectively. Homological analysis of ORF2 shows that 192-BJ07 is 96.3% identical to the documented HAstV-6 strain. Further, phylogenetic analysis indicates that different genomic regions are likely undergoing different evolutionary and selective pressures. No recombination event was observed in HAstV-6 in this study. Conclusion: The completely sequenced and characterized genome of HAstV-6 (192-BJ07) provides further insight into the genetics of astroviruses and aids in the surveillance and control of HAstV gastroenteritis. http://www.virologyj.com/content/7/1/29 Li Guo Richard Gonzalez Wei Wang Yongjun Li Glaucia Paranhos-Baccala Guy Vernet Jianwei Wang Virology Journal 2010, 7:29 2010-02-08T00:00:00Z doi:10.1186/1743-422X-7-29 Virology Journal 1743-422X 7 29 2010-02-08T00:00:00Z PDF Background: Antibodies produced in response to infection with any of the four serotypes of dengue virus generally provide homotypic immunity. However, prior infection or circulating maternal antibodies can also mediate a non-protective antibody response that can enhance the course of disease in a subsequent heterotypic infection. Naturally occurring human monoclonal antibodies can help us understand the protective and pathogenic roles of the humoral immune system in dengue virus infection. Results: Epstein-Barr Virus (EBV) transformation of B cells isolated from the peripheral blood of a human subject with previous dengue infection was performed. B cell cultures were screened by ELISA for antibodies to dengue (DENV) envelope (E) protein. ELISA positive cultures were cloned by limiting dilution. Three IgG1 human monoclonal antibodies (HMAbs) were purified and their binding specificity to E protein was verified by ELISA and biolayer interferometry. Neutralization and enhancement assays were conducted in epithelial and macrophage-like cell lines, repectively. All three HMAbs bound to E from at least two of the four DENV serotypes, one of the HMAbs was neutralizing, and all were able to enhance DENV infection. Conclusions: HMAbs against DENV can be successfully generated by EBV transformation of B cells from patients at least two years after naturally acquired DENV infections. These antibodies show different patterns of cross-reactivity, neutralizing, and enhancement activity. http://www.virologyj.com/content/7/1/28 John Schieffelin Joshua Costin Cindo Nicholson Nicole Orgeron Krystal Fontaine Sharon Isern Scott Michael James Robinson Virology Journal 2010, 7:28 2010-02-04T00:00:00Z doi:10.1186/1743-422X-7-28 Virology Journal 1743-422X 7 28 2010-02-04T00:00:00Z PDF The current pandemic influenza A H1N1 2009 (pH1N1) was first recognized in humans with acute respiratory diseases in April 2009 in Mexico, in swine in Canada in June, 2009 with respiratory disease, and in turkeys in Chile in June 2009 with a severe drop in egg production. Several experimental studies attempted to reproduce the disease in turkeys, but failed to produce respiratory infection in turkeys using standard inoculation routes. We demonstrated that pH1N1 virus can infect the reproductive tract of turkey hens after experimental intrauterine inoculation, causing decreased egg production. This route of exposure is realistic in modern turkey production because turkey hens are handled once a week for intrauterine insemination in order to produce fertile eggs. This understanding of disease exposure provides an improved understanding of the pathogenesis of the virus and can advance poultry husbandry to prevent disease outbreaks. http://www.virologyj.com/content/7/1/27 Mary Pantin-Jackwood Jamie Wasilenko Erica Spackman David Suarez David Swayne Virology Journal 2010, 7:27 2010-02-03T00:00:00Z doi:10.1186/1743-422X-7-27 Virology Journal 1743-422X 7 27 2010-02-03T00:00:00Z PDF The antiviral activity of native and esterified whey proteins fractions (alpha- lactalbumin, beta- lactoglobulin, and lactoferrin) was studied to inhibit tomato yellow leaf curl virus (TYLCV) on infected tomato plants. Whey proteins fractions and their esterified derivatives were sprayed into TYLCV-infected plants. Samples were collected from infected leaves before treatment, 7 and 15 days after treatment for DNA and molecular hybridization analysis. The most evident inhibition of virus replication was observed after 7 and 15 days using lactoferrin and alpha- lactalbumin, respectively. Native and esterified lactoferrin showed complete inhibition after 7 days. On the other hand, esterified beta- lactoglobulin showed less inhibition after 7 and 15 days wherea native beta- lactoglobulin was comparatively more effective after 15 days. The relative amount of viral DNA was less affected by the esterified alpha- lactalbumin whereas native alpha- lactalbumin inhibited virus replication completely after 15 days. These results indicate that native or modified whey proteins fractions can be used for controlling the TYLCV- infected plants. http://www.virologyj.com/content/7/1/26 Ashraf Abdelbacki Soad Taha Mahmoud Sitohy Abdelgawad Abou Dawood Mahmoud Abd-El Hamid Adel Rezk Virology Journal 2010, 7:26 2010-02-03T00:00:00Z doi:10.1186/1743-422X-7-26 Virology Journal 1743-422X 7 26 2010-02-03T00:00:00Z PDF Potato virus M (PVM, Carlavirus) is considered to be one of the most common potato viruses distributed worldwide. Sequences of the coat protein (CP) gene of several Canadian PVM isolates were determined. Phylogenetic analysis indicated that all known PVM isolates fell into two distinct groups and the isolates from Canada and the US clustered in the same group. The Canadian PVM isolates could be further divided into two sub-groups. Two molecular procedures, reverse transcription - polymerase chain reaction (RT-PCR) and restriction fragment length polymorphism (RFLP) were developed in this study for the detection and identification of PVM in potato tubers. RT-PCR was highly specific and only amplified PVM RNA from potato samples. PVM RNAs were easily detected in composite samples of 400 to 800 potato leaves or 200 to 400 dormant tubers. Restriction analysis of PCR amplicons with MscI was a simple method for the confirmation of PCR tests. Thus, RT-PCR followed by RFLP analysis may be a useful approach for screening potato samples on a large scale for the presence of PVM. http://www.virologyj.com/content/7/1/25 Huimin Xu Jeanette D'Aubin Jingbai Nie Virology Journal 2010, 7:25 2010-02-01T00:00:00Z doi:10.1186/1743-422X-7-25 Virology Journal 1743-422X 7 25 2010-02-01T00:00:00Z PDF Background: Dengue virus (DENV) is the causative agent of Dengue fever and the life-threatening Dengue Haemorrhagic fever or Dengue shock syndrome. In the absence of anti-viral agents or vaccine, there is an urgent need to develop an effective anti-viral strategy against this medically important viral pathogen. The initial interplay between DENV and the host cells may represent one of the potential anti-viral targeting sites. Currently the involvements of human membrane trafficking host genes or factors that mediate the infectious cellular entry of dengue virus are not well defined. Results: In this study, we have used a targeted small interfering RNA (siRNA) library to identify and profile key cellular genes involved in processes of endocytosis, cytoskeletal dynamics and endosome trafficking that are important and essential for DENV infection. The infectious entry of DENV into Huh7 cells was shown to be potently inhibited by siRNAs targeting genes associated with clathrin-mediated endocytosis. The important role of clathrin-mediated endocytosis was confirmed by the expression of well-characterized dominant-negative mutants of genes in this pathway and by using the clathrin endocytosis inhibitor chlorpromazine. Furthermore, DENV infection was shown to be sensitive to the disruption of human genes in regulating the early to late endosomal trafficking as well as the endosomal acidic pH. The importance and involvement of both actin and microtubule dynamics in mediating the infectious entry of DENV was also revealed in this study. Conclusions: Together, the findings from this study have provided a detail profiling of the human membrane trafficking cellular genes and the mechanistic insight into the interplay of these host genes with DENV to initiate an infection, hence broadening our understanding on the entry pathway of this medically important viral pathogen. These data may also provide a new potential avenue for development of anti-viral strategies and treatment of DENV infection. http://www.virologyj.com/content/7/1/24 Firzan Ang Andrew Phui Yew Wong Mary Mah Lee Ng Justin Jang Hann Chu Virology Journal 2010, 7:24 2010-02-01T00:00:00Z doi:10.1186/1743-422X-7-24 Virology Journal 1743-422X 7 24 2010-02-01T00:00:00Z PDF Background: Embryonated chicken eggs (ECE) are sometimes used for the primary isolation or passage of influenza viruses, other viruses, and certain bacteria. For small-scale experiments with pathogens that must be studied in biosafety level three (BSL3) facilities, inoculated ECE are sometimes manipulated and maintained in small egg incubators within a biosafety cabinet (BSC). To simplify the clean up and decontamination of an egg incubator in case of egg breakage, we explored whether ethylene breather bags could be used to encase ECE inoculated with pathogens. This concept was tested by determining embryo survival and examining virus yields in bagged ECE. Results: Virus yields acceptable for many applications were attained when influenza-, alpha-, flavi-, canine distemper-, and mousepox viruses were propagated in ECE sealed within ethylene breather bags. Conclusions: For many small-scale applications, ethylene breather bags can be used to encase ECE inoculated with various viruses. http://www.virologyj.com/content/7/1/23 Sara Hamilton Deirdre Daniels William Sosna Eric Jeppesen Julie Owells Micah Halpern Kimberly McCurdy Jonathan Rayner John Lednicky Virology Journal 2010, 7:23 2010-01-28T00:00:00Z doi:10.1186/1743-422X-7-23 Virology Journal 1743-422X 7 23 2010-01-28T00:00:00Z PDF Early diagnosis of dengue virus (DENV) infection is important for patient management and control of dengue outbreaks. The objective of this study was to analyze the usefulness of urine and saliva samples for early diagnosis of DENV infection by real time RT-PCR. Two febrile patients, who have been attended at the General Hospital of the School of Medicine of Ribeirao Preto, Sao Paulo University were included in the study. Serum, urine and saliva samples collected from both patients were subjected to real time RT-PCR for DENV detection and quantification. Dengue RNA was detected in serum, urine and saliva samples of both patients. Patient 1 was infected with DENV-2 and patient 2 with DENV-3. Data presented in this study suggest that urine and saliva could be used as alternative samples for early diagnosis of dengue virus infection when blood samples are difficult to obtain, e.g., in newborns and patients with hemorrhagic syndromes. http://www.virologyj.com/content/7/1/22 Telma Poloni Anibal Oliveira Helda Alfonso Larissa Galvao Alberto Amarilla Dimair Poloni Luiz Figueiredo Victor Aquino Virology Journal 2010, 7:22 2010-01-27T00:00:00Z doi:10.1186/1743-422X-7-22 Virology Journal 1743-422X 7 22 2010-01-27T00:00:00Z PDF Adenoviral vectors have been utilized for a variety of gene therapy applications. Our group has incorporated bioluminescent, flurographic reporters, and/or suicide genes within the adenovirus genome for analytical and/or therapeutic purposes. These molecules have also been incorporated as capsid components. Recognizing that incorporations at either locale yield potential advantages and disadvantages, our report evaluates the benefits of transgene incorporation versus capsid incorporation. To this end, we have genetically incorporated firefly luciferase within the early region 3 or at minor capsid protein IX and compared vector functionality by means of reporter readout. http://www.virologyj.com/content/7/1/21 Jing Li Aiman Fatima Svetlana Komarova Hideyo Ugai Priyanka Uprety Justin Roth Minghui Wang Robert Oster David Curiel Qiana Matthews Virology Journal 2010, 7:21 2010-01-26T00:00:00Z doi:10.1186/1743-422X-7-21 Virology Journal 1743-422X 7 21 2010-01-26T00:00:00Z PDF