We gratefully acknowledge the important contributions of Drs. John Anderson, Andrew Main and Shirley Tirrell to this study. This work was supported in part by grants from the Centers for Disease Control and Prevention (U50/CCU116806-01-1) and the US Department of Agriculture (58-6615-1-218, CONH00768, and CONH00773).

1. Mosquito sorting and identification 
<ol>
	<li>The following procedures are performed on an open laboratory bench in a dedicated biosafety level-2 (BSL-2) laboratory by staff who are trained to work with live mosquitoes. A "cold-chain" is maintained throughout the procedure.</li>
	<li>Anesthetize live adult mosquitoes by placing mosquito collection bag in a -20&deg; freezer for 5 minutes. Transfer collection bag to an insulated container containing dry ice. Close lid and expose mosquitoes to carbon-dioxide for 1-3...

<ol>
	<li>Chosewood, L. C., Wilson, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Biosafety in Microbiological and Biomedical Laboratories. , (2007).</li><li>Anderson, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolation+of+West+Nile+virus+from+mosquitoes,+crows,+and+a+Cooper's+hawk+in+Connecticut.">Isolation of West Nile virus from mosquitoes, crows, and a Cooper's hawk in Connecticut.</a> Science. 286, 2331-2333 (1999).</li><li>Armstrong, P. M., Andreadis, T. G., Anderson, J. F., Main, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolations+of+Potosi+virus+from+mosquitoes+(Diptera:+Culicidae)+collected+in+Connecticut.">Isolations of Potosi virus from mosquitoes (Diptera: Culicidae) collected in Connecticut.</a> J Med Entomol. 42, 875-881 (2005).</li><li>Armstrong, P. M., Andreadis, T. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+genetic+variant+of+La+Crosse+virus+(Bunyaviridae)+isolated+from+New+England.">A new genetic variant of La Crosse virus (Bunyaviridae) isolated from New England.</a> Am J Trop Med Hyg. 75, 491-496 (2006).</li><li>Andreadis, T. G., Anderson, J. F., Vossbrinck, C. R., Main, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidemiology+of+West+Nile+virus+in+Connecticut,+USA:+a+five+year+analysis+of+mosquito+data+1999-2003.">Epidemiology of West Nile virus in Connecticut, USA: a five year analysis of mosquito data 1999-2003.</a> Vector Borne Zoonotic Dis. 4, 360-378 (2004).</li><li>Andreadis, T. G., Anderson, J. F., Tirrell-Peck, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+isolations+of+eastern+equine+encephalitis+and+highlands+J+viruses+from+mosquitoes+(Diptera:+Culicidae)+during+a+1996+epizootic+in+southeastern+Connecticut.">Multiple isolations of eastern equine encephalitis and highlands J viruses from mosquitoes (Diptera: Culicidae) during a 1996 epizootic in southeastern Connecticut.</a> J Med Entomol. 35, 296-302 (1998).</li><li>Armstrong, P. M., Andreadis, T. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Eastern+equine+encephalitis+virus+in+mosquitoes+and+their+role+as+bridge+vectors.">Eastern equine encephalitis virus in mosquitoes and their role as bridge vectors.</a> Emerg Infect Dis. 16, 1869-1874 (2010).</li><li>Andreadis, T. G., Anderson, J. F., Armstrong, P. M., Main, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Isolations+of+Jamestown+Canyon+virus+(Bunyaviridae:+Orthobunyavirus)+from+field-collected+mosquitoes+(Diptera:+Culicidae)+in+Connecticut,+USA:+a+ten-year+analysis,+1997-2006.">Isolations of Jamestown Canyon virus (Bunyaviridae: Orthobunyavirus) from field-collected mosquitoes (Diptera: Culicidae) in Connecticut, USA: a ten-year analysis, 1997-2006.</a> Vector Borne Zoonotic Dis. 8, 175-188 (2008).</li><li>Beaty, B. J., Calisher, C. H., Shope, R., Lennette, E. H., Lennette, D. A., Lennette, E. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+11.">Chapter 11.</a> Diagnostic Procedures for Viral, Rickettsial, and Chlamydial Infections. , 189-212 (1995).</li><li>Karabatsos, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> International Catalogue of Arboviruses Including Certain Other Viruses of Vertebrates. , (1985).</li><li>Lanciotti, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+detection+of+west+nile+virus+from+human+clinical+specimens,+field-collected+mosquitoes,+and+avian+samples+by+a+TaqMan+reverse+transcriptase-PCR+assay.">Rapid detection of west nile virus from human clinical specimens, field-collected mosquitoes, and avian samples by a TaqMan reverse transcriptase-PCR assay.</a> J Clin Microbiol. 38, 4066-4071 (2000).</li><li>Lambert, A. J., Martin, D. A., Lanciotti, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+North+American+eastern+and+western+equine+encephalitis+viruses+by+nucleic+acid+amplification+assays.">Detection of North American eastern and western equine encephalitis viruses by nucleic acid amplification assays.</a> J Clin Microbiol. 41, 379-385 (2003).</li></ol>

Vero cell culture assay serves as an effective method to screen field-collected mosquitoes for a diversity of viruses. This contrasts to molecular methods that specifically target one or a few viruses of interest. Moreover, we have found that Vero cell culture assay is equally if not more sensitive than RT-PCR7 and provides us with virus isolates that are stored in our reference collection for future studies. Nevertheless, cell culture systems may not be appropriate in many instances. This approach incurs a...

<table border="1">
	<tbody>
	 <tr>
 	<th>Name of reagent/ equipment</th>
 	<th>Company</th>
 	<th>Catalog Number</th>
 	</tr>
 	<tr>
 	<td>Fetal bovine serum</td>
 	<td>Gibco &ndash; Invitrogen</td>
 	<td>16140</td>
 	</tr>
 	<tr>
 <td>Anti-biotic/mycotic</td>
 <td>Gibco &ndash; Invitrogen</td>
 <td>15240</td>
 </tr>
 <tr>
 <td>Sodium bicarbonate NaHCO3, 7.5% Soln.</td>
 <td>Gibco &ndash; Invitrogen</td>
 <td>25080</td>
 </tr>
 <tr>
 <td>L-Glutamine 200mM 100x</td>
 <td>Gibco-Invitrogen</td>
 <td>25030</td>
 </tr>
 <tr>
 <td>Powdered minimal essential medium (MEM)</td>
 <td>Gibco &ndash; Invitrogen</td>
 <td>11700</td>
 </tr>
 <tr>
 <td>10X Dulbecco&rsquo;s PBS</td>
 <td>Gibco &ndash; Invitrogen</td>
 <td>14080</td>
 </tr>
 <tr>
 <td>Trypsin-EDTA</td>
 <td>Gibco &ndash; Invitrogen</td>
 <td>15400</td>
 </tr>
 <tr>
 <td>Rabbit serum</td>
 <td>Gibco &ndash; Invitrogen</td>
 <td>16120</td>
 </tr>
 <tr>
 <td>Vero Cells (Clone E6)</td>
 <td>ATCC</td>
 <td>CRL-1586</td>
 </tr>
 <tr>
 <td>Small tissue culture flasks, vented caps, 25 cm2</td>
 <td>Falcon - Becton Dickinson</td>
 <td>353112</td>
 </tr>
 <tr>
 <td>Large tissue culture flasks, vented caps, 175 cm2</td>
 <td>Falcon &ndash; Becton Dickinson</td>
 <td>353108</td>
 </tr>
 <tr>
 <td>Copper-coated BB&rsquo;s, 4.5 mm</td>
 <td>Crosman</td>
 <td>0767</td>
 </tr>
 <tr>
 <td>Mixer Mill</td>
 <td>Retsch</td>
 <td>MM300</td>
 </tr>
 <tr>
 <td>Isopack freezer racks</td>
 <td>Eppendorf</td>
 <td>022510240</td>
 </tr>
 </tbody>
</table>

detection of infectious virus from field-collected mosquitoes by vero cell culture assay

Mosquitoes transmit a number of distinct viruses including important human pathogens such as West Nile virus, dengue virus, and chickungunya virus. Many of these viruses have intensified in their endemic ranges and expanded to new territories, necessitating effective surveillance and control programs to respond to these threats. One strategy to monitor virus activity involves collecting large numbers of mosquitoes from endemic sites and testing them for viral infection. In this article, we describe how to handle, process, and screen field-collected mosquitoes for infectious virus by Vero cell culture assay. Mosquitoes are sorted by trap location and species, and grouped into pools containing &le;50 individuals. Pooled specimens are homogenized in buffered saline using a mixer-mill and the aqueous phase is inoculated onto confluent Vero cell cultures (Clone E6). Cell cultures are monitored for cytopathic effect from days 3-7 post-inoculation and any viruses grown in cell culture are identified by the appropriate diagnostic assays. By utilizing this approach, we have isolated 9 different viruses from mosquitoes collected in Connecticut, USA, and among these, 5 are known to cause human disease. Three of these viruses (West Nile virus, Potosi virus, and La Crosse virus) represent new records for North America or the New England region since 1999. The ability to detect a wide diversity of viruses is critical to monitoring both established and newly emerging viruses in the mosquito population.

Watch this Scientific Journal Video about Detection of Infectious Virus from Field-collected Mosquitoes by Vero Cell Culture Assay at JoVE.com

Detection of Infectious Virus from Field-collected Mosquitoes by Vero Cell Culture Assay

We describe a method to process and screen field-collected mosquitoes for a diversity of viruses by Vero cell culture assay. By employing this technique, we have detected 9 different viruses from 4 taxonomic families in mosquitoes collected in Connecticut.

Mosquitoes transmit a number of distinct viruses including important human pathogens such as West Nile virus, dengue virus, and chickungunya virus. Many ...

detection-infectious-virus-from-field-collected-mosquitoes-vero-cell

Research

JoVE Journal

Immunology and Infection

18.3K ビュー.  The Connecticut Agricultural Experiment Station. 我々はプロセスに方法を記述し、画面のヴェロ細胞培養アッセイによりウイルスの多様性のための蚊をフィールド集めた。この手法を採用することにより、我々はコネチカットで収集された蚊の4分類の家族から9種類のウイルスを検出した。

ビデオ: Detection of Infectious Virus from Field-collected Mosquitoes by Vero Cell Culture Assay

We describe a method to process and screen field-collected mosquitoes for a diversity of viruses by Vero cell culture assay. By employing this technique, we have detected 9 different viruses from 4 taxonomic families in mosquitoes collected in...

mosquito-associated virus isolation from field-collected mosquitoes

Mosquito-Associated Virus Isolation from Field-Collected Mosquitoes

Numerous novel virus-like sequences have been found in mosquitoes due to the extensive use of sequencing technologies. We provide an effective procedure for isolating and amplifying viruses using vertebrate and mosquito cell lines, which might serve as the basis for future studies on mosquito-associated viruses, including mosquito-borne and mosquito-specific...

zika virus infectious cell culture system and the in vitro prophylactic effect of interferons

Zika Virus Infectious Cell Culture System and the In Vitro Prophylactic Effect of Interferons

Zika Virus (ZIKV), an emerging pathogen, is linked to fetal developmental abnormalities and microcephaly. The establishment of an effective infectious cell culture system is crucial for studies of ZIKV replication as well as vaccine and drug development. In this study, various virological assays pertaining to ZIKV are illustrated and...

Zika Virus Infectious Cell Culture System and the In Vitro Prophylactic Effect of Interferons

a multi-detection assay for malaria transmitting mosquitoes

A Multi-detection Assay for Malaria Transmitting Mosquitoes

Malaria transmitting mosquitoes have a number of epidemiologically important characteristics that can only be detected using molecular techniques. Utilizing a MALDI-TOF based SNP genotyping platform, we developed an assay for simultaneously detecting multiple key traits (species, insecticide resistance, parasite infection and host choice) of malaria...

assay to determine the virus infectious dose of drosophila c virus in cultured insect cells

In this video, we demonstrate the cytopathic effect assay to determine the tissue culture infective viral dose of Drosophila C virus on Drosophila S2* cells. A range of viral concentrations are used to infect the cultured cells. The proportion of cells exhibiting structural changes is determined, and this data is used to calculate the tissue culture infective...

Assay to Determine the Virus Infectious Dose of Drosophila C Virus in Cultured Insect Cells

rescue and characterization of recombinant virus from a new world zika virus infectious clone

Rescue and Characterization of Recombinant Virus from a New World Zika Virus Infectious Clone

This protocol describes the recovery of infectious Zika virus from a two-plasmid infectious cDNA...

an ex vivo chicken primary bursal-cell culture model to study infectious bursal disease virus pathogenesis

An Ex Vivo Chicken Primary Bursal-cell Culture Model to Study Infectious Bursal Disease Virus Pathogenesis

Here we describe the isolation of chicken primary bursal cells from the bursa of Fabricius, the culture and infection of the cells with infectious bursal disease virus, and the quantification of viral...

An Ex Vivo Chicken Primary Bursal-cell Culture Model to Study Infectious Bursal Disease Virus Pathogenesis

vector competence analyses on aedes aegypti mosquitoes using zika virus

Vector Competence Analyses on Aedes aegypti Mosquitoes using Zika Virus

The presented protocol can determine the vector competence of Aedes aegypti mosquito populations for a given virus, such as Zika, in a containment...

Vector Competence Analyses on Aedes aegypti Mosquitoes using Zika Virus

detection of plasmodium sporozoites in anopheles mosquitoes using an enzyme-linked immunosorbent assay

Detection of Plasmodium Sporozoites in Anopheles Mosquitoes using an Enzyme-linked Immunosorbent Assay

This protocol describes a sandwich enzyme-linked immunosorbent assay to detect salivary gland sporozoites in mosquitoes. Using easily available monoclonal antibodies, the method enables cost-effective, high-throughput detection of mosquitoes carrying Plasmodium falciparum or Plasmodium vivax. The method is suitable for malaria transmission research, including vector...

Detection of Plasmodium Sporozoites in Anopheles Mosquitoes using an Enzyme-linked Immunosorbent Assay

Randomly select five tubes of virus from minus 80 degrees Celsius storage. While the cells are settling, fill 10 sterile 1.5-milliliter microcentrifuge tubes with 450 microliters of sterile complete medium, and add 50 microliters of virus stock to the first 1.5-milliliter tube containing 450 microliters of sterile complete medium, diluting the suspensions tenfold per step to the 12th...

direct agroinoculation of maize seedlings by injection with recombinant foxtail mosaic virus and sugarcane mosaic virus infectious clones

Direct Agroinoculation of Maize Seedlings by Injection with Recombinant Foxtail Mosaic Virus and Sugarcane Mosaic Virus Infectious Clones

An Agrobacterium-based injection (agroinjection) protocol is presented for the inoculation of foxtail mosaic virus&#160;and sugarcane mosaic virusclones into maize seedlings. Inoculation in this manner leads to viral infection, virus-induced gene silencing of marker genes, and viral overexpression of...

virus plaque assay: a technique to measure infectious herpes simplex virus via quantification of plaques formed in monolayer of virus-infected cells

This video describes the virus plaque assay of the infectious herpes simplex virus or HSV. The diluted viral particles are inoculated to the monolayer of epithelial cells. Upon incubation, the virus forms plaques and is counted visually to determine the infectious virus...

Virus Plaque Assay: A Technique to Measure Infectious Herpes Simplex Virus via Quantification of Plaques Formed in Monolayer of Virus-Infected Cells

in vitro selection of aptamers to differentiate infectious from non-infectious viruses

In Vitro Selection of Aptamers to Differentiate Infectious from Non-Infectious Viruses

We provide a protocol that can be generally applied to select aptamers that bind to infectious viruses only and not to viruses that have been rendered non-infectious by a disinfection method or to any other similar viruses. This opens the possibility of determining infectivity status in portable and rapid...

epa method 1615. measurement of enterovirus and norovirus occurrence in water by culture and rt-qpcr. part iii. virus detection by rt-qpcr

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. Part III. Virus Detection by RT-qPCR

Here we present a procedure to quantify enterovirus and norovirus in environmental and drinking waters using reverse transcription-quantitative PCR. Mean virus recovery from groundwater with this standardized procedure from EPA Method 1615 was 20% for poliovirus and 30% for murine...

visualizing efficacy of pesticides against disease vector mosquitoes in the field

Visualizing Efficacy of Pesticides Against Disease Vector Mosquitoes in the Field

The efficacy of public health pesticides targeting nuisance and disease-vector insects is not uniform across different ecological zones. Here we present a system of techniques using captive vector insects as sentinels for pesticide efficacy to derive electronic maps supporting the standard evaluation of pesticides across multiple...

Repeat the process for every one or two wells until the entire plate is filled with the virus samples being plaqued. Gently rock the entire plate by...

simultaneous quantification of selected kynurenines analyzed by liquid chromatography-mass spectrometry in medium collected from cancer cell cultures

Simultaneous Quantification of Selected Kynurenines Analyzed by Liquid Chromatography-Mass Spectrometry in Medium Collected from Cancer Cell Cultures

Described here is a protocol for the determination of four different tryptophan metabolites generated in the kynurenine pathway (kynurenine, 3-hydroxykynurenine, xanthurenic acid, 3-hydroxyanthranilic acid) in the medium collected from cancer cell cultures analyzed by liquid chromatography coupled with a single quadrupole mass...

a bacterial oral feeding assay with antibiotic-treated mosquitoes

A Bacterial Oral Feeding Assay with Antibiotic-Treated Mosquitoes

This article presents a protocol to investigate the effect of individual mosquito gut bacteria, including isolation and identification of mosquito midgut cultivable microbes, antibiotic depletion of mosquito gut bacteria, and reintroduce one specific bacteria...

epa method 1615. measurement of enterovirus and norovirus occurrence in water by culture and rt-qpcr. ii. total culturable virus assay

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. II. Total Culturable Virus Assay

Here we present a procedure to measure total culturable viruses using the Buffalo Green Monkey kidney cell line. The procedure provides a standardized tool for measuring the occurrence of infectious viruses in environmental and drinking...

measuring dengue virus rna in the culture supernatant of infected cells by real-time quantitative polymerase chain reaction

Measuring Dengue Virus RNA in the Culture Supernatant of Infected Cells by Real-time Quantitative Polymerase Chain Reaction

Real-time quantitative polymerase chain reaction analysis combined with reverse transcription (RT-qPCR) has been widely used to measure the level of RNA virus infections. Here we present a direct RT-qPCR assay, which does not require an RNA purification step, developed for the quantification of several RNA viruses, including dengue...

Live Cell Imaging of Alphaherpes Virus Anterograde Transport and Spread

Advances in live cell fluorescence microscopy techniques, as well as the construction of recombinant viral strains that express fluorescent fusion proteins have enabled real-time visualization of transport and spread of alphaherpes virus infection of neurons. The utility of novel fluorescent fusion proteins to viral membrane, tegument, and capsids, in conjunction with live cell imaging, identified viral particle assemblies undergoing transport within axons. Similar tools have been successfully employed for analyses of cell-cell spread of viral particles to quantify the number and diversity of virions transmitted between cells. Importantly, the techniques of live cell imaging of anterograde transport and spread produce a wealth of information including particle transport velocities, distributions of particles, and temporal analyses of protein localization. Alongside classical viral genetic techniques, these methodologies have provided critical insights into important mechanistic questions. In this article we describe in detail the imaging methods that were developed to answer basic questions of alphaherpes virus transport and spread.

Live cell imaging of alphaherpes virus infections enables analysis of the dynamic events of directed transport and intercellular spread. Here, we present methodologies that utilize recombinant viral strains expressing fluorescent fusion proteins to facilitate visualization of viral assemblies during infection of primary neurons.

Advances in live cell fluorescence microscopy  techniques, as well as the construction of recombinant viral strains that  express fluorescent fusion ...

Organoids as Model for Infectious Diseases: Culture of Human and Murine Stomach Organoids and Microinjection of Helicobacter Pylori

Recently infection biologists have employed stem cell derived cultures to answer the need for new and better models to study host-pathogen interactions. Three cellular sources have been used: Embryonic stem cells (ESC), induced pluripotent stem cells (iPSC) or adult stem cells. Here, culture of mouse and human gastric organoids derived from adult stem cells is described and used for infection with the gastric pathogen Helicobacter pylori. Human gastric glands are isolated from resection material, seeded in a basement matrix and embedded in medium containing growth factors epidermal growth factor (EGF), R-spondin, Noggin, Wnt, fibroblast growth factor (FGF) 10, gastrin and transforming growth factor (TGF) beta inhibitor. In these conditions, gastric glands grow into 3-dimensional organoids containing 4 lineages of the stomach. The organoids expand indefinitely and can be frozen and thawed similarly as cell lines. For infection studies, bacteria are microinjected into the lumen of the organoids. Infected organoids are processed for imaging. The described methods can be adapted to other organoids and infections with other bacteria, viruses or parasites. This allows the study of infection-induced changes in primary cells.

Stem cell derived cultures harbor tremendous potential to model infectious diseases. Here, the culture of mouse and human gastric organoids derived from adult stem cells is described. The organoids are microinjected with the gastric pathogen Helicobacter pylori.

Recently infection biologists have employed stem cell derived cultures to answer the need for new and better models to study host-pathogen interactions. ...

Zika Virus (ZIKV) is an emerging pathogen that is linked to fetal developmental abnormalities such as microcephaly, eye defects, and impaired growth. ZIKV is an RNA virus of the Flaviviridae family. ZIKV is mainly transmitted by mosquitoes, but can also be spread by maternal to fetal vertical transmission as well as sexual contact. To date, there are no reliable treatment or vaccine options available to protect those infected by the virus. The development of a reproducible, effective Zika virus infectious cell culture system is critical for studying the molecular mechanisms of ZIKV replication as well as drug and vaccine development. In this regard, a protocol describing a mammalian cell-based in vitro Zika virus culture system for viral production and growth analysis is reported here. Details on the formation of plaques by Zika virus on a cell monolayer and plaque assay for measuring viral titer are presented. Viral genome replication kinetics and double-stranded RNA genome replicatory intermediates are determined. This culture platform was utilized to screen against a library of a small set of cytokines resulting in the identification of interferon-&#945; (IFN-&#945;), IFN-&#946; and IFN-&#947; as potent inhibitors of Zika viral growth. In summary, an in vitro infectious Zika viral culture system and various virological assays are demonstrated in this study, which has the potential to greatly benefit the research community in elucidating further the mechanisms of viral pathogenesis and the evolution of viral virulence. Antiviral IFN-alpha can further be evaluated as a prophylactic, post-exposure prophylactic, and treatment option for Zika virus infections in high-risk populations, including infected pregnant women.

Zika Virus (ZIKV), an emerging pathogen, is linked to fetal developmental abnormalities and microcephaly. The establishment of an effective infectious cell culture system is crucial for studies of ZIKV replication as well as vaccine and drug development. In this study, various virological assays pertaining to ZIKV are illustrated and discussed.

Zika Virus (ZIKV) is an emerging pathogen that is linked to fetal developmental abnormalities such as microcephaly, eye defects, and impaired growth. ZIKV ...

Infectious cDNA clones allow for genetic manipulation of a virus, thus facilitating work on vaccines, pathogenesis, replication, transmission and viral evolution. Here we describe the construction of an infectious clone for Zika virus (ZIKV), which is currently causing an explosive outbreak in the Americas. To prevent toxicity to bacteria that is commonly observed with flavivirus-derived plasmids, we generated a two-plasmid system which separates the genome at the NS1 gene and is more stable than full-length constructs that could not be successfully recovered without mutations. After digestion and ligation to join the two fragments, full-length viral RNA can be generated by in vitro transcription with T7 RNA polymerase. Following electroporation of transcribed RNA into cells, virus was recovered that exhibited similar in vitro growth kinetics and in vivo virulence and infection phenotypes in mice and mosquitoes, respectively.

This protocol describes the recovery of infectious Zika virus from a two-plasmid infectious cDNA clone.

Infectious cDNA clones allow for genetic manipulation of a virus, thus facilitating work on vaccines, pathogenesis, replication, transmission and viral ...

Rapid, Safe, and Simple Manual Bedside Nucleic Acid Extraction for the Detection of Virus in Whole Blood Samples

The rapid diagnosis of an infection is essential for the outbreak management, risk containment, and patient care. We have previously shown a method for the rapid bedside inactivation of the Ebola virus during blood sampling for safe nucleic acid (NA) tests by adding a commercial lysis/binding buffer directly into the vacuum blood collection tubes. Using this bedside inactivation approach, we have developed a safe, rapid, and simplified bedside NA extraction method for the subsequent detection of a virus in lysis/binding buffer-inactivated whole blood. The NA extraction is directly performed in the blood collection tubes and requires no equipment or electricity. 
After the blood is collected into the lysis/binding buffer, the contents are mixed by flipping the tube by hand, and the mixture is incubated for 20 min at room temperature. Magnetic glass particles (MGPs) are added to the tube, and the contents are mixed by flipping the collection tube by hand. The MGPs are then collected on the side of the blood collection tube using a magnetic holder or a magnet and a rubber band. The MGPs are washed three times, and after the addition of elution buffer directly into the collection tube, the NAs are ready for NA tests, such as qPCR or isothermal loop amplification (LAMP), without the removal of the MGPs from the reaction. The NA extraction method is not dependent on any laboratory facilities and can easily be used anywhere (e.g., in field hospitals and hospital isolation wards). When this NA extraction method is combined with LAMP and a portable instrument, a diagnosis can be obtained within 40 min of the blood collection.

Here, we present a protocol for the rapid virus nucleic acid extraction from the virus-inactivated whole blood. The extraction is performed directly in the blood collection tubes and requires no equipment or electricity. The method is not dependent on laboratory facilities and can be used anywhere (e.g., in field hospitals).

The rapid diagnosis of an infection is essential for the outbreak management, risk containment, and patient care. We have previously shown a method for ...

Infectious bursal disease virus (IBDV) is a birnavirus of economic importance to the poultry industry. The virus infects B cells, causing morbidity, mortality, and immunosuppression in infected birds. In this study, we describe the isolation of chicken primary bursal cells from the bursa of Fabricius, the culture and infection of the cells with IBDV, and the quantification of viral replication. The addition of chicken CD40 ligand significantly increased cell proliferation fourfold over six days of culture and significantly enhanced cell viability. Two strains of IBDV, a cell-culture adapted strain, D78, and a very virulent strain, UK661, replicated well in the ex vivo cell cultures. This model will be of use in determining how cells respond to IBDV infection and will permit a reduction in the number of infected birds used in IBDV pathogenesis studies. The model can also be expanded to include other viruses and could be applied to different species of birds.

Here we describe the isolation of chicken primary bursal cells from the bursa of Fabricius, the culture and infection of the cells with infectious bursal disease virus, and the quantification of viral replication.

Infectious bursal disease virus (IBDV) is a birnavirus of economic importance to the poultry industry. The virus infects B cells, causing morbidity, ...

Identification of Mouse and Human Antibody Repertoires by Next-Generation Sequencing

The immense adaptability of antigen recognition by antibodies is the basis of the acquired immune system. Despite our understanding of the molecular mechanisms underlying the production of the vast repertoire of antibodies by the acquired immune systems, it has not yet been possible to arrive at a global view of a complete antibody repertoire. In particular, B cell repertoires have been regarded as a black box because of their astronomical number of antibody clones. However, next-generation sequencing technologies are enabling breakthroughs to increase our understanding of the B cell repertoire. In this report, we describe a simple and efficient method to visualize and analyze whole individual mouse and human antibody repertoires. From the immune organs, representatively from spleen in mice and peripheral blood mononuclear cells in humans, total RNA was prepared, reverse transcribed, and amplified using the 5&#39;-RACE method. Using a universal forward primer and antisense primers for the antibody class-specific constant domains, antibody mRNAs were uniformly amplified in proportions reflecting their frequencies in the antibody populations. The amplicons were sequenced by next-generation sequencing (NGS), yielding more than 105 antibody sequences per immunological sample. We describe the protocols for antibody sequence analyses including V(D)J-gene-segment annotation, a bird&#39;s-eye view of the antibody repertoire, and our computational methods.

Here, we describe protocols for the analysis and visualization of the structure and constitution of whole antibody repertoires. This involves the acquisition of vast sequences of antibody RNA using next-generation sequencing.

The immense adaptability of antigen recognition by antibodies is the basis of the acquired immune system. Despite our understanding of the molecular ...

Human Serum Anti-aquaporin-4 Immunoglobulin G Detection by Cell-based Assay

Anti-aquaporin-4 (AQP4) immunoglobulin G (IgG) is the core diagnostic biomarker for neuromyelitis optica spectrum disorders (NMOSD). The cell-based assay (CBA) is a widely used method to detect anti-AQP4 IgG in human serum with high sensitivity and specificity. Briefly, serum anti-AQP4 IgG is captured by AQP4-transfected cell that is fixed on the biochip then detected by a fluorescein-labelled secondary antibody. Fluorescence microscopy is utilized to visualize the fluorescence, and the intensity of fluorescence is evaluated by at least two experienced clinicians. A final diagnosis of NMOSD can be made based on the combination of anti-AQP4 IgG detection results, clinical manifestations, and neuroradiological findings. According to previous studies, CBA is more sensitive and specific than other anti-AQP4 IgG detection methods, and it can be applied to both clinical diagnosis and studies of NMOSD. The method has limitations; for example, an international scale to evaluate serum anti-AQP4 IgG titers is still lacking. Here, a detailed protocol for human serum anti-AQP4 IgG detection using CBA is described.

Cell-based assay is a widely used method to detect serum anti-aquaporin-4 immunoglobulin G. This method could be applied to clinical diagnosis and scientific researches of neuromyelitis optical spectrum disorders.

Anti-aquaporin-4 (AQP4) immunoglobulin G (IgG) is the core diagnostic biomarker for neuromyelitis optica spectrum disorders (NMOSD). The cell-based assay ...

Purification of High Yield Extracellular Vesicle Preparations Away from Virus

One of the major hurdles in the field of extracellular vesicle (EV) research today is the ability to achieve purified EV preparations in a viral infection setting. The presented method is meant to isolate EVs away from virions (i.e., HIV-1), allowing for a higher efficiency and yield compared to conventional ultracentrifugation methods. Our protocol contains three steps: EV precipitation, density gradient separation, and particle capture. Downstream assays (i.e., Western blot, and PCR) can be run directly following particle capture. This method is advantageous over other isolation methods (i.e., ultracentrifugation) as it allows for the use of minimal starting volumes. Furthermore, it is more user friendly than alternative EV isolation methods requiring multiple ultracentrifugation steps. However, the presented method is limited in its scope of functional EV assays as it is difficult to elute intact EVs from our particles. Furthermore, this method is tailored towards a strictly research-based setting and would not be commercially viable.

This protocol isolates extracellular vesicles (EVs) away from virions with high efficiency and yield by incorporating EV precipitation, density gradient ultracentrifugation, and particle capture to allow for a streamlined workflow and a reduction of starting volume requirements, resulting in reproducible preparations for use in all EV research.

One of the major hurdles in the field of extracellular vesicle (EV) research today is the ability to achieve purified EV preparations in a viral infection ...

The procedures presented describe a generalized methodology to infect Aedes aegypti mosquitoes with Zika virus under laboratory conditions to determine the rate of infection, disseminated infection, and potential transmission of the virus in the mosquito population in question. These procedures are widely utilized with various modifications in vector competence evaluations globally. They are important in determining the potential role that a given mosquito (i.e., species, population, individual) may play in the transmission of a given agent.

The presented protocol can determine the vector competence of Aedes aegypti mosquito populations for a given virus, such as Zika, in a containment setting.

The procedures presented describe a generalized methodology to infect Aedes aegypti mosquitoes with Zika virus under laboratory conditions to determine ...