scholarly journals Recombinant Hepatitis A Virus Antigen: Improved Production and Utility in Diagnostic Immunoassays

1998 ◽  
Vol 36 (7) ◽  
pp. 2014-2018 ◽  
Author(s):  
F. D. LaBrecque ◽  
D. R. LaBrecque ◽  
D. Klinzman ◽  
S. Perlman ◽  
J. B. Cederna ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Neutralizing Antibodies ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Limit Of Detection ◽  
Current Method ◽  
Recombinant Antigen ◽  
Enzyme Linked Immunosorbent Assay ◽  
Culture Methods ◽  
Recombinant Vaccinia

Hepatitis A virus (HAV) immunoassays use cell culture-derived HAV antigen to detect HAV-specific antibodies. The current method of production of HAV antigen in tissue culture is time-consuming and expensive. We previously expressed the HAV open reading frame in recombinant vaccinia viruses (rV-ORF). The recombinant HAV polyprotein was accurately processed and was assembled into subviral particles. These particles were bound by HAV-neutralizing antibodies and were able to elicit antibodies which were detected by commercial immunoassays. The present investigation compared the production of HAV antigen by standard tissue culture methods to the production of HAV antigen with the recombinant vaccinia virus system. In addition, HAV and rV-ORF antigens were assessed for their utility in diagnostic immunoassays. Serum or plasma samples from HAV antibody-positive and antibody-negative individuals were evaluated by immunoassay that used either HAV or rV-ORF antigen. All samples (86 of 86) in which HAV antibody was detected by a commercial enzyme-linked immunosorbent assay (ELISA) also tested positive by the recombinant antigen-based immunoassay (VacRIA). Similarly, all samples (50 of 50) that were HAV antibody negative also tested negative by the VacRIA. The lower limit of detection of HAV antibody was similar among immunoassays with either HAV or rV-ORF antigen. Thus, in the population studied, the sensitivity and specificity of the VacRIA were equivalent to those of the commercial ELISA. Since production of recombinant antigen is faster and less expensive than production of traditional HAV antigen, the development of diagnostic HAV antibody tests with recombinant HAV antigen appears warranted.

Detection of Hepatitis a Virus and other Enteroviruses in Wastewater and Surface Water Samples by Gene Probe Assay

1991 ◽  
Vol 24 (2) ◽  
pp. 267-272 ◽  
Author(s):  
S. Dubrou ◽  
H. Kopecka ◽  
J. M. Lopez Pila ◽  
J. Maréchal ◽  
J. Prévot
Keyword(s):  
Surface Water ◽  
Cell Cultures ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Limit Of Detection ◽  
Blot Hybridization ◽  
Noncoding Region ◽  
Gene Probe ◽  
Dot Blot ◽  
Lower Efficiency

Enteroviruses were specifically detected by dot blot hybridization when using poliovirus type 1 (PV1) derived subgenomic radiolabeled cRNA probes (riboprobes) in environmental water specimens and in the cell cultures in which the viruses were amplificated. The riboprobe corresponding to the 5' noncoding sequence detected the majority of enteroviruses. Hepatitis A virus (HAV) was specifically detected by an HAV cRNA probe corresponding to the 5' noncoding region of its genome. By this test, the limit of detection of coxsackievirus B5 and echovirus 7 seeded in mineral water was 103 to 104 PFU/spot. In cell cultures, positive signals were observed in the lysates of cells infected by one PFU. Higher positive signals were obtained with a short PV1 probe (nt 221-670) corresponding to the 5' noncoding region, which is a well preserved sequence among the enteroviruses, than with PV1 genomic probe. Hybridization allowed a good detection of enteroviral RNAs in wastewater specimens, but with a lower efficiency in surface water. In this case, amplification of viruses in the cell cultures gave significant hybridization results.

Detection of Hepatitis a Virus in Drinking Water by Enzyme -Immunoassay Using Ultracentrifugation for Virus Concentration

1985 ◽  
Vol 17 (10) ◽  
pp. 39-41 ◽  
Author(s):  
A. Schnattinger
Keyword(s):  
Membrane Filtration ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Solid Phase ◽  
Phosphate Buffer Solution ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Concentration ◽  
Buffer Solution ◽  
Solution Ph ◽  
Two Stage

Ten litres of tapwater were seeded with 200 µl (8×108 HAV particles) of a commercial (Organon Teknika) suspension of hepatitis A virus. Following WALTER and RÜDIGER (1981), the contaminated tapwater was treated with a two-stage technique for concentration of viruses from solutions with low virus titers. The two-stage technique consists of aluminium hydroxideflocculation (200 mg/l Al2(SO4)3. 18 H2O, pH 5,4-5,6) as first stage, the second stage of a lysis of aluminium hydroxidegel with citric acid/sodium citrate-buffer (pH 4,7; 1 ml/l sample), separation of viruses from the lysate by ultracentrifugation and suspension in 1 ml phosphate buffer solution (pH 7,2). A commercial solid phase enzyme-linked immunosorbent assay (ELISA) was used for the detection of HAV. HAV was detecterl in the 10.000:1 concentrates, but not in the seeded 101 samples. Approximately 4×108 of the inoculated 8×108 HAV particles were found in the 1 ml concentrates. The efficiency of detection is about 50%, the virus concentration 5000-fold. Although the percentage loss of HAV in comparison with concentration by means of membrane filtration is similar, the ultracentrifugation method yields a larger sample/concentrate ratio, so that smaller amounts of HAV can be detected more efficiently because of the smaller end-volume.

scholarly journals Quantification of Hepatitis A Virus in Shellfish by Competitive Reverse Transcription-PCR with Coextraction of Standard RNA

1999 ◽  
Vol 65 (1) ◽  
pp. 322-326 ◽  
Author(s):  
Charlotte Arnal ◽  
Virginie Ferre-Aubineau ◽  
Berangere Mignotte ◽  
Berthe Marie Imbert-Marcille ◽  
Sylviane Billaudel
Keyword(s):  
Tissue Culture ◽  
Reverse Transcription ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Internal Standard ◽  
Wild Type ◽  
Rt Pcr ◽  
Reverse Transcription Pcr ◽  
Reproducible Method ◽  
Dna Enzyme Immunoassay

ABSTRACT To quantify hepatitis A virus (HAV) in experimentally contaminated mussels, we developed an internal standard RNA with a 7-nucleotide deletion for competitive reverse transcription (RT)-PCR. Deposited directly into the sample, this standard was used both as extraction control and as quantification tool. After coextraction and competitive RT-PCR, standard and wild-type products were detected by differential hybridization with specific probes and a DNA enzyme immunoassay. The quantifiable range with this reproducible method was 104 to 107 copies of HAV/gram or 400 to 106 50% tissue culture infective doses/ml.

scholarly journals A Novel Marsupial Hepatitis A Virus Corroborates Complex Evolutionary Patterns Shaping the Genus Hepatovirus

2018 ◽  
Vol 92 (13) ◽  
Author(s):  
Ianei de Oliveira Carneiro ◽  
Anna-Lena Sander ◽  
Namá Silva ◽  
Andres Moreira-Soto ◽  
Andrea Normann ◽  
...  
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Genome Structure ◽  
Northeastern Brazil ◽  
Enzyme Linked Immunosorbent Assay ◽  
Evolutionary Patterns ◽  
Host Switch ◽  
Content Type ◽  
Evolutionary Origins ◽  
Phylogenetic Reconstructions

ABSTRACT The discovery of highly diverse nonprimate hepatoviruses illuminated the evolutionary origins of hepatitis A virus (HAV) ancestors in mammals other than primates. Marsupials are ancient mammals that diverged from other Eutheria during the Jurassic. Viruses from marsupials may thus provide important insight into virus evolution. To investigate Hepatovirus macroevolutionary patterns, we sampled 112 opossums in northeastern Brazil. A novel marsupial HAV (MHAV) in the Brazilian common opossum ( Didelphis aurita ) was detected by nested reverse transcription-PCR (RT-PCR). MHAV concentration in the liver was high, at 2.5 × 10 9 RNA copies/g, and at least 300-fold higher than those in other solid organs, suggesting hepatotropism. Hepatovirus seroprevalence in D. aurita was 26.6% as determined using an enzyme-linked immunosorbent assay (ELISA). Endpoint titers in confirmatory immunofluorescence assays were high, and marsupial antibodies colocalized with anti-HAV control sera, suggesting specificity of serological detection and considerable antigenic relatedness between HAV and MHAV. MHAV showed all genomic hallmarks defining hepatoviruses, including late-domain motifs likely involved in quasi-envelope acquisition, a predicted C-terminal pX extension of VP1, strong avoidance of CpG dinucleotides, and a type 3 internal ribosomal entry site. Translated polyprotein gene sequence distances of at least 23.7% from other hepatoviruses suggested that MHAV represents a novel Hepatovirus species. Conserved predicted cleavage sites suggested similarities in polyprotein processing between HAV and MHAV. MHAV was nested within rodent hepatoviruses in phylogenetic reconstructions, suggesting an ancestral hepatovirus host switch from rodents into marsupials. Cophylogenetic reconciliations of host and hepatovirus phylogenies confirmed that host-independent macroevolutionary patterns shaped the phylogenetic relationships of extant hepatoviruses. Although marsupials are synanthropic and consumed as wild game in Brazil, HAV community protective immunity may limit the zoonotic potential of MHAV. IMPORTANCE Hepatitis A virus (HAV) is a ubiquitous cause of acute hepatitis in humans. Recent findings revealed the evolutionary origins of HAV and the genus Hepatovirus defined by HAV in mammals other than primates in general and in small mammals in particular. The factors shaping the genealogy of extant hepatoviruses are unclear. We sampled marsupials, one of the most ancient mammalian lineages, and identified a novel marsupial HAV (MHAV). The novel MHAV shared specific features with HAV, including hepatotropism, antigenicity, genome structure, and a common ancestor in phylogenetic reconstructions. Coevolutionary analyses revealed that host-independent evolutionary patterns contributed most to the current phylogeny of hepatoviruses and that MHAV was the most drastic example of a cross-order host switch of any hepatovirus observed so far. The divergence of marsupials from other mammals offers unique opportunities to investigate HAV species barriers and whether mechanisms of HAV immune control are evolutionarily conserved.

scholarly journals Biliary Secretion of Quasi-Enveloped Human Hepatitis A Virus

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Asuka Hirai-Yuki ◽  
Lucinda Hensley ◽  
Jason K. Whitmire ◽  
Stanley M. Lemon
Keyword(s):  
Life Cycle ◽  
Bile Acids ◽  
Neutralizing Antibodies ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Acute Infection ◽  
Cell Culture Supernatant ◽  
Particle Type ◽  
Human Bile

ABSTRACTHepatitis A virus (HAV) is an unusual picornavirus that is released from cells cloaked in host-derived membranes. These quasi-enveloped virions (eHAV) are the only particle type circulating in blood during infection, whereas only nonenveloped virions are shed in feces. The reason for this is uncertain. Hepatocytes, the only cell type known to support HAV replicationin vivo, are highly polarized epithelial cells with basolateral membranes facing onto hepatic (blood) sinusoids and apical membranes abutting biliary canaliculi from which bile is secreted to the gut. To assess whether eHAV and nonenveloped virus egress from cells via vectorially distinct pathways, we studied infected polarized cultures of Caco-2 and HepG2-N6 cells. Most (>99%) progeny virions were released apically from Caco-2 cells, whereas basolateral (64%) versus apical (36%) release was more balanced with HepG2-N6 cells. Both apically and basolaterally released virions were predominantly enveloped, with no suggestion of differential vectorial release of eHAV versus naked virions. Basolateral to apical transcytosis of either particle type was minimal (<0.02%/h) in HepG2-N6 cells, arguing against this as a mechanism for differences in membrane envelopment of serum versus fecal virus. High concentrations of human bile acids converted eHAV to nonenveloped virions, whereas virus present in bile from HAV-infectedIfnar1−/−Ifngr1−/−andMavs−/−mice banded over a range of densities extending from that of eHAV to that of nonenveloped virions. We conclude that nonenveloped virions shed in feces are derived from eHAV released across the canalicular membrane and stripped of membranes by the detergent action of bile acids within the proximal biliary canaliculus.IMPORTANCEHAV is a hepatotropic, fecally/orally transmitted picornavirus that can cause severe hepatitis in humans. Recent work reveals that it has an unusual life cycle. Virus is found in cell culture supernatant fluids in two mature, infectious forms: one wrapped in membranes (quasi-enveloped) and another that is nonenveloped. Membrane-wrapped virions circulate in blood during acute infection and are resistant to neutralizing antibodies, likely facilitating HAV dissemination within the liver. On the other hand, virus shed in feces is nonenveloped and highly stable, facilitating epidemic spread and transmission to naive hosts. Factors controlling the biogenesis of these two distinct forms of the virus in infected humans are not understood. Here we characterize vectorial release of quasi-enveloped virions from polarized epithelial cell cultures and provide evidence that bile acids strip membranes from eHAV following its secretion into the biliary tract. These results enhance our understanding of the life cycle of this unusual picornavirus.

scholarly journals Determinants of Hepatitis A Vaccine Immunity in a Cohort of Human Immunodeficiency Virus-Infected Children Living in Switzerland

2012 ◽  
Vol 19 (11) ◽  
pp. 1751-1757 ◽  
Author(s):  
Pierre Alex Crisinel ◽  
Klara Maria Posfay-Barbe ◽  
Christoph Aebi ◽  
Jean-Jacques Cheseaux ◽  
Christian Kahlert ◽  
...  
Keyword(s):  
T Cell ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Geometric Mean ◽  
Vaccine Dose ◽  
High Rate ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Children ◽  
Vaccine Responses ◽  
Cell Counts

ABSTRACTVaccination in HIV-infected children is often less effective than in healthy children. The goal of this study was to assess vaccine responses to hepatitis A virus (HAV) in HIV-infected children. Children of the Swiss Mother and Child HIV Cohort Study (MoCHiV) were enrolled prospectively. Recommendations for initial, catch-up, and additional HAV immunizations were based upon baseline antibody concentrations and vaccine history. HAV IgG was assessed by enzyme-linked immunosorbent assay (ELISA) with a protective cutoff value defined as ≥10 mIU/ml. Eighty-seven patients were included (median age, 11 years; range, 3.4 to 21.2 years). Forty-two patients were seropositive (48.3%) for HAV. Among 45 (51.7%) seronegative patients, 36 had not received any HAV vaccine dose and were considered naïve. Vaccine responses were assessed after the first dose in 29/35 naïve patients and after the second dose in 33/39 children (25 initially naïve patients, 4 seronegative patients, and 4 seropositive patients that had already received 1 dose of vaccine). Seroconversion was 86% after 1 dose and 97% after 2 doses, with a geometric mean concentration of 962 mIU/ml after the second dose. A baseline CD4+T cell count below 750 cells/μl significantly reduced the post-2nd-dose response (P= 0.005). Despite a high rate of seroconversion, patients with CD4+T cell counts of <750/μl had lower anti-HAV antibody concentrations. This may translate into a shorter protection time. Hence, monitoring humoral immunity may be necessary to provide supplementary doses as needed.

Evaluation of a Sensitive Reverse Transcription PCR–Enzyme-Linked Immunosorbent Assay for Detection of Hepatitis A Virus in Oysters (Saccostrea glomerata) on the East Coast of the Gulf of Thailand

2014 ◽  
Vol 77 (5) ◽  
pp. 859-863 ◽  
Author(s):  
URAIWAN INTAMASO ◽  
SITTHISAK KETKHUNTHOD
Keyword(s):  
Immunosorbent Assay ◽  
Reverse Transcription ◽  
Hepatitis A ◽  
East Coast ◽  
Hepatitis A Virus ◽  
Detection Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Gulf Of Thailand ◽  
Rt Pcr ◽  
The Gulf Of Thailand

Hepatitis A virus (HAV) contamination in food can lead to major health problems. We developed a combination reverse transcription (RT) PCR method plus enzyme-linked immunosorbent assay (ELISA) to detect HAV in fresh oysters harvested along the east coast of the Gulf of Thailand. Viral nucleic acid was extracted via the glycine–arginine–polyethylene glycol method followed by RT-PCR amplification with specifically designed primers against HAV and an ELISA to detect the digoxigenin-labeled RT-PCR products. The ELISA in concert with the RT-PCR protocol further increased the detection sensitivity by 100-fold for the HAV genome and 10-fold in artificially contaminated oysters. The overall sensitivity of the RT-PCR in combination with the ELISA was 31.88 pg and 16 PFU/g, respectively. The ELISA increases the specificity of the RT-PCR assay for detecting naturally occurring HAV in oysters. This combined RT-PCR-ELISA approach is a practical and sensitive method for HAV detection and can be utilized in routine screening for HAV in shellfish.

scholarly journals Hepatitis A Virus-Specific Immunoglobulin A Mediates Infection of Hepatocytes with Hepatitis A Virus via the Asialoglycoprotein Receptor

2000 ◽  
Vol 74 (23) ◽  
pp. 10950-10957 ◽  
Author(s):  
Andreas Dotzauer ◽  
Ulrike Gebhardt ◽  
Karen Bieback ◽  
Ulrich Göttke ◽  
Anja Kracke ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Neutralizing Antibodies ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Immunoglobulin A ◽  
Asialoglycoprotein Receptor ◽  
Primary Hepatocytes ◽  
Mouse Hepatocyte ◽  
Specific Immunoglobulin ◽  
Bile Fluid

ABSTRACT The mechanisms underlying the hepatotropism of hepatitis A virus (HAV) and the relapsing courses of HAV infections are unknown. In this report, we show for a mouse hepatocyte model that HAV-specific immunoglobulin A (IgA) mediates infection of hepatocytes with HAV via the asialoglycoprotein receptor, which binds and internalizes IgA molecules. Proof of HAV infection was obtained by detection of HAV minus-strand RNA, which is indicative for virus replication, and quantification of infectious virions. We demonstrate that human hepatocytes also ingest HAV–anti-HAV IgA complexes by the same mechanism, resulting in infection of the cells, by using the HepG2 cell line and primary hepatocytes. The relevance of this surrogate receptor mechanism in HAV pathogenesis lies in the fact that HAV, IgA, and antigen-IgA complexes use the same pathway within the organism, leading from the gastrointestinal tract to the liver via blood and back to the gastrointestinal tract via bile fluid. Therefore, HAV-specific IgA antibodies produced by gastrointestinal mucosa-associated lymphoid tissue may serve as carrier and targeting molecules, enabling and supporting HAV infection of IgA receptor-positive hepatocytes and, in the case of relapsing courses, allowing reinfection of the liver in the presence of otherwise neutralizing antibodies, resulting in exacerbation of liver disease.

scholarly journals Solid-phase enzyme-linked immunosorbent assay for detection of hepatitis A virus

1978 ◽  
Vol 8 (3) ◽  
pp. 277-282 ◽  
Author(s):  
S A Locarnini ◽  
S M Garland ◽  
N I Lehmann ◽  
R C Pringle ◽  
I D Gust
Keyword(s):  
Immunosorbent Assay ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Solid Phase ◽  
Field Work ◽  
Enzyme Linked Immunosorbent Assay ◽  
Technical Equipment ◽  
Immune Electron Microscopy ◽  
Naked Eye ◽  
Household Contacts

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of hepatitis A virus in human fecal specimens. Investigations with 88 fecal specimens from 77 patients with suspected viral hepatitis and 8 of their household contacts showed that ELISA was as specific and sensitive as radioimmunoassay and almost as sensitive as immune electron microscopy. The ELISA is quick and simple to perform, does not require sophisticated technical equipment, and can be read with the naked eye, making it suitable for field work and rapid diagnosis.

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