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Viruses Aug 2021Human norovirus is the leading cause of foodborne illness globally. One of the challenges in detecting noroviruses is the identification of a completely broadly reactive...
Human norovirus is the leading cause of foodborne illness globally. One of the challenges in detecting noroviruses is the identification of a completely broadly reactive ligand; however, all detection ligands generated to date target the viral capsid, the outermost of which is the most variable region of the genome. The VPg is a protein covalently linked to the viral genome that is necessary for replication but hitherto remains underexplored as a target for detection or therapeutics. The purpose of this work was to generate nucleic acid aptamers against human norovirus (Norwalk) and cultivable surrogate (Tulane) VPgs for future use in detection and therapeutics. Eight rounds of positive-SELEX and two rounds of counter-SELEX were performed. Five and eight unique aptamer sequences were identified for Norwalk and Tulane VPg, respectively, all of which were predicted to be stable (∆G < -5.0) and one of which occurred in both pools. All candidates displayed binding to both Tulane and Norwalk VPg (positive:negative > 5.0), and all but two of the candidates displayed very strong binding (positive:negative > 10.0), significantly higher than binding to the negative control protein ( < 0.05). Overall, this work reports a number of aptamer candidates found to be broadly reactive and specific for in vitro-expressed VPgs across genus that could be used for future application in detection or therapeutics. Future work characterizing binding of the aptamer candidates against native VPgs and in therapeutic applications is needed to further evaluate their application.
Topics: Aptamers, Nucleotide; Caliciviridae; DNA, Single-Stranded; Genome, Viral; Humans; Nucleic Acids; SELEX Aptamer Technique; Viral Proteins
PubMed: 34578297
DOI: 10.3390/v13091716 -
The New England Journal of Medicine Jul 1993Diarrhea occurs frequently among persons with the acquired immunodeficiency syndrome, but the cause often remains unknown. We used a group of diagnostic assays to... (Review)
Review
BACKGROUND
Diarrhea occurs frequently among persons with the acquired immunodeficiency syndrome, but the cause often remains unknown. We used a group of diagnostic assays to determine which viruses were etiologic agents of diarrhea in a group of persons infected with the human immunodeficiency virus (HIV).
METHODS
Stool and serum specimens were obtained from HIV-infected patients enrolled in a longitudinal study in Atlanta. Fecal specimens from patients with diarrhea and from control patients without diarrhea were screened by electron microscopy, polyacrylamide-gel electrophoresis, and enzyme immunoassays for rotaviruses, enteric adenoviruses, caliciviruses, picobirnaviruses, and astroviruses. Paired serum samples were tested for antibody responses to Norwalk virus and picobirnavirus.
RESULTS
Viruses were detected in 35 percent of 109 fecal specimens from patients with diarrhea but in only 12 percent of 113 specimens from those without diarrhea (P < 0.001). Specimens from patients with diarrhea were more likely than those from patients without diarrhea to have astrovirus (12 percent vs. 2 percent, P = 0.003); picobirnavirus (9 percent vs. 2 percent, P = 0.017); caliciviruses, including small round structured viruses (6 percent vs. 1 percent, P = 0.062); and adenoviruses (9 percent vs. 3 percent, P = 0.047). They were also more likely to have a mixed viral infection (6 percent vs. 0 percent, P = 0.006). With the use of polyacrylamide-gel electrophoresis to analyze concentrated RNA extracts from stool, picobirnavirus was detected in fecal specimens from 6 of the 65 patients with diarrhea and was associated with prolonged viral shedding and chronic diarrhea. No rotaviruses, enteric adenoviruses, or instances of seroconversion to positivity for Norwalk virus were observed.
CONCLUSIONS
Novel enteric viruses such as astrovirus and picobirnavirus may be more important etiologic agents of diarrhea in HIV-infected patients than previously recognized and may be more common than either bacterial or parasitic enteropathogens.
Topics: Adenoviruses, Human; CD4-Positive T-Lymphocytes; Caliciviridae; Diarrhea; Feces; Female; Gastroenteritis; HIV Infections; HIV-1; Humans; Male; Mamastrovirus; Picornaviridae; Prospective Studies; Viruses
PubMed: 8099429
DOI: 10.1056/NEJM199307013290103 -
Journal of Virology Nov 1992Norwalk virus capsid protein was produced by expression of the second and third open reading frames of the Norwalk virus genome, using a cell-free translation system and...
Norwalk virus capsid protein was produced by expression of the second and third open reading frames of the Norwalk virus genome, using a cell-free translation system and baculovirus recombinants. Analysis of the expressed products showed that the second open reading frame encodes a protein with an apparent molecular weight of 58,000 (58K protein) and that this protein self-assembles to form empty viruslike particles similar to native capsids in size and appearance. The antigenicity of these particles was demonstrated by immunoprecipitation and enzyme-linked immunosorbent assays of paired serum samples from volunteers who developed illness following Norwalk virus challenge. These particles also induced high levels of Norwalk virus-specific serum antibody in laboratory animals following parenteral inoculation. A minor 34K protein was also found in infected insect cells. Amino acid sequence analysis of the N terminus of the 34K protein indicated that the 34K protein was a cleavage product of the 58K protein. The availability of large amounts of recombinant Norwalk virus particles will allow the development of rapid, sensitive, and reliable tests for the diagnosis of Norwalk virus infection as well as the implementation of structural studies.
Topics: Antibody Formation; Antigens, Viral; Baculoviridae; Capsid; Cell-Free System; DNA, Recombinant; DNA, Viral; Molecular Weight; Norwalk virus; Open Reading Frames; Transcription, Genetic
PubMed: 1328679
DOI: 10.1128/JVI.66.11.6527-6532.1992 -
Microbes and Infection Mar 2016
Topics: Aedes; Animals; Disease Outbreaks; Disease Transmission, Infectious; Global Health; Humans; Insect Vectors; Mosquito Control; Zika Virus Infection
PubMed: 26706817
DOI: 10.1016/j.micinf.2015.12.003 -
Indian Journal of Public Health 1994
Review
Topics: Acute Disease; Child, Preschool; Developing Countries; Diarrhea; Enterobacteriaceae Infections; Fluid Therapy; Humans; India; Infant; Infant, Newborn; Intestinal Diseases, Parasitic; Rotavirus Infections
PubMed: 7835992
DOI: No ID Found -
Journal of Food Protection Dec 2012Human noroviruses (NoVs) are a leading cause of acute gastroenteritis and are frequently transmitted by contaminated food, water, hands, and environmental surfaces....
Human noroviruses (NoVs) are a leading cause of acute gastroenteritis and are frequently transmitted by contaminated food, water, hands, and environmental surfaces. Little is known about their environmental stability and/or which alternative microorganisms can serve as effective surrogates. To examine whether Escherichia coli and male-specific coliphage MS2 can be appropriate surrogates for NoVs, approximately 6.8 log genomic equivalent copies of Norwalk virus (NV), and 6.0 to 6.5 log PFU or CFU of MS2 and E. coli, respectively, were inoculated onto stainless steel coupons and held at 4°C, room temperature (RT), or 37°C over a period of 75 min (E. coli and MS2) to 4 weeks. These three microorganisms were also seeded into phosphate-buffered saline (PBS) and sampled at different time intervals for up to 6 weeks. MS2 and E. coli survived approximately 15 min at 37°C, 45 min at RT, and 60 min at 4°C on the stainless steel surfaces. In contrast, NV RNA titers were reduced by only 2.4 log at 37°C, 1.5 log at RT, and 0.9 log at 4°C after 4 weeks. MS2 and E. coli were able to survive at least 5 weeks in PBS at 4°C and RT, and NV was stable in PBS at 4°C and RT for at least 6 weeks. However, E. coli, MS2, and NV were completely inactivated after 1-, 4-, and 5-week incubations in PBS at 37°C, respectively. These findings indicate that NoVs are highly persistent on environmental surfaces and in PBS solution at different temperatures. While E. coli does not appear to be an appropriate surrogate for NoVs, MS2 could be more relevant for modeling the environmental persistence of NoVs under wet conditions, but not under dry conditions.
Topics: Coliphages; Consumer Product Safety; Equipment Contamination; Escherichia coli; Food Contamination; Food Microbiology; Humans; Hydrogen-Ion Concentration; Models, Biological; Norwalk virus; Stainless Steel; Temperature; Time Factors
PubMed: 23212011
DOI: 10.4315/0362-028X.JFP-12-197 -
Journal of Virology Sep 2013Passive immunoprophylaxis or immunotherapy with norovirus-neutralizing monoclonal antibodies (MAbs) could be a useful treatment for high-risk populations, including...
Passive immunoprophylaxis or immunotherapy with norovirus-neutralizing monoclonal antibodies (MAbs) could be a useful treatment for high-risk populations, including infants and young children, the elderly, and certain patients who are debilitated or immunocompromised. In order to obtain antinorovirus MAbs with therapeutic potential, we stimulated a strong adaptive immune response in chimpanzees to the prototype norovirus strain Norwalk virus (NV) (genogroup I.1). A combinatorial phage Fab display library derived from mRNA of the chimpanzees' bone marrow was prepared, and four distinct Fabs reactive with Norwalk recombinant virus-like particles (rVLPs) were recovered, with estimated binding affinities in the subnanomolar range. Mapping studies showed that the four Fabs recognized three different conformational epitopes in the protruding (P) domain of NV VP1, the major capsid protein. The epitope of one of the Fabs, G4, was further mapped to a specific site involving a key amino acid residue, Gly365. One additional specific Fab (F11) was recovered months later from immortalized memory B cells and partially characterized. The anti-NV Fabs were converted into full-length IgG (MAbs) with human γ1 heavy chain constant regions. The anti-NV MAbs were tested in the two available surrogate assays for Norwalk virus neutralization, which showed that the MAbs could block carbohydrate binding and inhibit hemagglutination by NV rVLP. By mixing a single MAb with live Norwalk virus prior to challenge, MAbs D8 and B7 neutralized the virus and prevented infection in a chimpanzee. Because chimpanzee immunoglobulins are virtually identical to human immunoglobulins, these chimpanzee anticapsid MAbs may have a clinical application.
Topics: Amino Acid Sequence; Animals; Antibodies, Monoclonal; Antibodies, Neutralizing; Antibody Specificity; Caliciviridae Infections; Epitope Mapping; Gastroenteritis; Humans; Immunization, Passive; Immunoglobulin Fab Fragments; Models, Molecular; Molecular Sequence Data; Mutagenesis, Site-Directed; Norwalk virus; Pan troglodytes; Peptide Library; Protein Conformation; Sequence Homology, Amino Acid; Species Specificity; Viral Structural Proteins
PubMed: 23785216
DOI: 10.1128/JVI.01376-13 -
Expert Review of Vaccines 2015Human norovirus infection causes significant medical and financial costs in the USA and abroad. Some populations, including young children, the elderly, and the... (Review)
Review
Human norovirus infection causes significant medical and financial costs in the USA and abroad. Some populations, including young children, the elderly, and the immunocompromised, are at heightened risk of infection with this virus and subsequent complications, while others, such as healthcare workers and food handlers are at increased risk of transmitting it, and some are at risk of both. Human noroviruses are heterogeneous with new strains emerging periodically. In addition to viral diversity, incompletely understood characteristics, such as virus-host cell binding and duration of immunity after infection add to the challenges of creating a norovirus vaccine. Although much progress has been made in recent years, many questions remain to be answered. In this review, we discuss the important areas and relevant literature in considering human norovirus vaccine development and potential targets for implementation.
Topics: Caliciviridae Infections; Drug Discovery; Gastroenteritis; Global Health; Health Services Needs and Demand; Humans; Norovirus; Viral Vaccines
PubMed: 26224658
DOI: 10.1586/14760584.2015.1073110 -
PloS One Sep 2009Freshwater lakes and ponds present an ecological interface between humans and a variety of host organisms. They are a habitat for the larval stage of many insects and...
Freshwater lakes and ponds present an ecological interface between humans and a variety of host organisms. They are a habitat for the larval stage of many insects and may serve as a medium for intraspecies and interspecies transmission of viruses such as avian influenza A virus. Furthermore, freshwater bodies are already known repositories for disease-causing viruses such as Norwalk Virus, Coxsackievirus, Echovirus, and Adenovirus. While RNA virus populations have been studied in marine environments, to this date there has been very limited analysis of the viral community in freshwater. Here we present a survey of RNA viruses in Lake Needwood, a freshwater lake in Maryland, USA. Our results indicate that just as in studies of other aquatic environments, the majority of nucleic acid sequences recovered did not show any significant similarity to known sequences. The remaining sequences are mainly from viral types with significant similarity to approximately 30 viral families. We speculate that these novel viruses may infect a variety of hosts including plants, insects, fish, domestic animals and humans. Among these viruses we have discovered a previously unknown dsRNA virus closely related to Banna Virus which is responsible for a febrile illness and is endemic to Southeast Asia. Moreover we found multiple viral sequences distantly related to Israeli Acute Paralysis virus which has been implicated in honeybee colony collapse disorder. Our data suggests that due to their direct contact with humans, domestic and wild animals, freshwater ecosystems might serve as repositories of a wide range of viruses (both pathogenic and non-pathogenic) and possibly be involved in the spread of emerging and pandemic diseases.
Topics: Databases, Genetic; Ecology; Fresh Water; Genetic Techniques; Genetic Variation; Genome, Viral; Maryland; Phylogeny; RNA Viruses; Sequence Alignment; Software; Water Microbiology
PubMed: 19787045
DOI: 10.1371/journal.pone.0007264 -
Virology Oct 2015Noroviruses are the most common cause of acute gastroenteritis in humans. Development of an effective vaccine is required for reducing their outbreaks. In order to...
Noroviruses are the most common cause of acute gastroenteritis in humans. Development of an effective vaccine is required for reducing their outbreaks. In order to develop a GI norovirus vaccine, Newcastle disease virus vectors, rLaSota and modified rBC, were used to express VP1 protein of Norwalk virus. Co-expression of VP1 and VP2 proteins by Newcastle disease virus vectors resulted in enhanced expression of Norwalk virus VP1 protein and self-assembly of VP1 protein into virus-like particles. Furthermore, the Norwalk virus-specific IgG response induced in mice by Newcastle disease virus vectors was similar to that induced by baculovirus-expressed virus-like particles in mice. However, the modified rBC vector in the presence of VP2 protein induced significantly higher levels of cellular and mucosal immune responses than those induced by baculovirus-expressed VLPs. These results indicate that Newcastle disease virus has great potential for developing a live Norwalk virus vaccine by inducing humoral, cellular and mucosal immune responses in humans.
Topics: Animals; Antibodies, Viral; Capsid Proteins; Female; Genetic Vectors; Immunity, Cellular; Immunity, Mucosal; Immunoglobulin G; Mice, Inbred BALB C; Newcastle disease virus; Norwalk virus; Treatment Outcome; Vaccines, Subunit; Vaccines, Synthetic; Vaccines, Virus-Like Particle; Viral Vaccines
PubMed: 26099695
DOI: 10.1016/j.virol.2015.06.003