Novel Surrogate Neutralizing Assay Supports Parvovirus B19 Vaccine Development for Children with Sickle Cell Disease.
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ABSTRACT:
SUBMITTER: Penkert RR
PROVIDER: S-EPMC8402426 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Infections caused by human parvovirus B19 are known to be controlled mainly by neutralizing antibodies. To analyze the immune reaction against parvovirus B19 proteins, four cell lines secreting human immunoglobulin G monoclonal antibodies (MAbs) were generated from two healthy donors and one human immunodeficiency virus type 1-seropositive individual with high serum titers against parvovirus. One MAb is specific for nonstructural protein NS1 (MAb 1424), two MAbs are specific for the unique region of minor capsid protein VP1 (MAbs 1418-1 and 1418-16), and one MAb is directed to major capsid protein VP2 (MAb 860-55D). Two MAbs, 1418-1 and 1418-16, which were generated from the same individual have identity in the cDNA sequences encoding the variable domains, with the exception of four base pairs resulting in only one amino acid change in the light chain. The NS1- and VP1-specific MAbs interact with linear epitopes, whereas the recognized epitope in VP2 is conformational. The MAbs specific for the structural proteins display strong virus-neutralizing activity. The VP1- and VP2-specific MAbs have the capacity to neutralize 50% of infectious parvovirus B19 in vitro at 0.08 and 0.73 microgram/ml, respectively, demonstrating the importance of such antibodies in the clearance of B19 viremia. The NS1-specific MAb mediated weak neutralizing activity and required 47.7 micrograms/ml for 50% neutralization. The human MAbs with potent neutralizing activity could be used for immunotherapy of chronically B19 virus-infected individuals and acutely infected pregnant women. Furthermore, the knowledge gained regarding epitopes which induce strongly neutralizing antibodies may be important for vaccine development.
| S-EPMC104439 | biostudies-literature
Project description:BACKGROUND AND PURPOSE:Case-control studies suggest that acute infection transiently increases the risk of childhood arterial ischemic stroke. We hypothesized that an unbiased pathogen discovery approach utilizing MassTag-polymerase chain reaction would identify pathogens in the blood of childhood arterial ischemic stroke cases. METHODS:The multicenter international VIPS study (Vascular Effects of Infection in Pediatric Stroke) enrolled arterial ischemic stroke cases, and stroke-free controls, aged 29 days through 18 years. Parental interview included questions on recent infections. In this pilot study, we used MassTag-polymerase chain reaction to test the plasma of the first 161 cases and 34 controls enrolled for a panel of 28 common bacterial and viral pathogens. RESULTS:Pathogen DNA was detected in no controls and 14 cases (8.7%): parvovirus B19 (n=10), herpesvirus 6 (n=2), adenovirus (n=1), and rhinovirus 6C (n=1). Parvovirus B19 infection was confirmed by serologies in all 10; infection was subclinical in 8. Four cases with parvovirus B19 had underlying congenital heart disease, whereas another 5 had a distinct arteriopathy involving a long-segment stenosis of the distal internal carotid and proximal middle cerebral arteries. CONCLUSIONS:Using MassTag-polymerase chain reaction, we detected parvovirus B19-a virus known to infect erythrocytes and endothelial cells-in some cases of childhood arterial ischemic stroke. This approach can generate new, testable hypotheses about childhood stroke pathogenesis.
| S-EPMC5614850 | biostudies-literature
Project description:BackgroundHuman parvovirus B19 is the etiologic agent of erythema infectiosum in children. It is also associated with other clinical manifestations in different target groups. Patients with chronic hemolytic anemia are at high risk of developing acute erythroblastopenia following infection by the virus. They usually become highly viremic and pose an increased risk of virus transmission. Close monitoring of such high risk groups is required for epidemiologic surveillance and disease prevention activities. Here we report a molecular epidemiological study on B19 virus infection in Tunisian patients with chronic hemolytic anemia.MethodsThis study was conducted on 92 young chronic hemolytic anemia patients who attended the same ward at the National Bone Marrow Transplantation Center of Tunis and 46 controls from a different hospital. Screening for IgM and IgG anti-B19 antibodies was performed using commercially available enzyme immunoassays and B19 DNA was detected by nested PCR in the overlapping VP1/VP2 region. DNA was sequenced using dideoxy-terminator cycle sequencing technology.ResultsAnti-parvovirus B19 IgG antibodies were detected in 26 of 46 sickle-cell anemia patients, 18 of 46 beta-thalassemia and 7 of 46 controls. Anti-parvovirus B19 IgM antibodies were detected only in 4 of the sickle-cell anemia patients: two siblings and two unrelated who presented with acute erythroblastopenia at the time of blood collection for this study and had no history of past transfusion. B19 DNA was detected only in sera of these four patients and the corresponding 288 bp nested DNA amplicons were sequenced. The sequences obtained were all identical and phylogenetic analysis showed that they belonged to a new B19 virus strain of Genotype1.ConclusionA new parvovirus B19 strain of genotype1 was detected in four Tunisian patients with sickle-cell anemia. Virus transmission appeared to be nosocomial and resulted in acute erythroblastopenia in the four patients. The possibility of independent transmission of this B19 variant to the patients is unlikely in light of the present epidemiological data. However this possibility cannot be ruled out because of the low genetic variability of the virus.
| S-EPMC2151067 | biostudies-literature
Project description:BackgroundParvovirus B19 (B19 V) infection had been reported to be more frequent with serious clinical outcomes in patients with sickle cell disease (SCD) than in the general population. There is a wide variation in data among the existing literature regarding the seroprevalence of B19 V in patients with SCD. These data require further summary and analyses for better accuracy. This systematic review and meta-analysis was done to estimate the seroprevalence of B19 V in patients with SCD.MethodsThis study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The databases of MEDLINE/PubMed, Virtual Health Library (VHL), ScienceDirect, Google Scholar, and OpenGrey were used for the systematic search. The random-effects model was used to estimate the pooled prevalence with the corresponding 95% confidence interval (CI) using OpenMeta Analyst software. Publication bias was estimated based on Begg's test, Egger's test, and examination of the funnel plot. Subgroup analyses and metaregression were used to explore the moderators of heterogeneity between studies.ResultsA total of 18 studies including 2890 patients were analyzed. The overall IgG seroprevalence of B19 V infection among patients with SCD was found to be 48.8% (95% CI 39.5%-58.0%). Evidence of publication bias was not detected. Evidence of acute viral infection detected by positive IgM antibodies among the screened SCD patients was found in 8.30% (95% CI 5.20%-11.4%) of them. There was a statistically significant association between seroprevalence of B19 V and geographical areas.ConclusionThere was a high prevalence of B19 V in patients with SCD. Healthcare providers need to be aware of the magnitude of B19 V infection in patients with SCD to ensure effective management. This review could provide a comprehensive view of B19 V prevalence in this susceptible population.
| S-EPMC6925911 | biostudies-literature
Project description:Three genotypes have been identified within the parvovirus B19 species (B19V), and such genetic diversity may have significant implications for the development of molecular detection assays. In the present study, B19V genetic variability has been examined on a subset of genomic sequences available in the NCBI nucleotide database, and a quantitative PCR (qPCR) assay able to detect, differentiate, and quantify all viral variants has been established. The designed primers and probes have been used for the development of alternative detection formats, based on a combined use of intercalating dye and genotype-specific hydrolysis probes. The qPCR assay analytical performances have been determined on the 1st WHO International Reference Panel for Parvovirus B19 Genotypes. The developed qPCR protocols allow for the detection of genotypes 1 to 3 with equal accuracy, and with a limit of detection (LOD) of 200 IU/ml. A comparison of routine performance was carried out with respect to a previously established assay specifically validated on B19V genotype 1. For 130 clinical samples analyzed, 126 showed concordant results (31 positive and 97 negative), while 4 showed discordant results. Overall, the genotype-specific qPCR assay showed a sensitivity of 93.94% and a specificity of 97.94%, with an agreement rate of 96.92%. The proposed qPCR assay and the alternative protocols developed, each with robust performance, may allow choice with respect to operational systems and diagnostic requirements and might contribute to provide a more reliable diagnostic service and epidemiological surveillance of B19 virus.
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Project description:Coxsackievirus A6 (CV-A6) is one of pathogens causing hand, foot and mouth disease (HFMD) and becomes a new challenge to HFMD control. In this study, we first built a single-round pseudovirus infection system for CV-A6, and then developed a pseudovirus luciferase assay (PVLA) for anti-CV-A6 neutralizing antibody (NtAb) quantification. Since cytopahtic effect (CPE) is considered as the gold standard test for anti-enterovirus NtAb detection, a comparison study has been performed using 318 clinical serum samples, as measured both by PVLA and CPE. The sensitivity and specificity of PVLA was 94.9% (95% CI between 90.8-97.5%) and 92.7% (95% CI between 86.6-96.6%), respectively. Statistical analysis revealed that PVLA and CPE were highly correlated (spearman r = 0.931, P < 0.0001) and in good agreement (94.0%, 95% CI between 90.8-96.4%), showing that PVLA could be used as a surrogate assay for anti-CV-A6 NtAb detection and served as a valuable tool for CV-A6 vaccine evaluation and CV-A6 epidemiological surveillance.
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Project description:Ancient human parvovirus B19 in Eurasia reveals its long-term association with humans
| PRJEB26712 | ENA
Project description:Parvovirus B19 (B19V) is a human pathogenic virus of clinical relevance, characterized by a selective tropism for erythroid progenitor cells in bone marrow. Relevant information on viral characteristics and lifecycle can be obtained from experiments involving engineered genetic systems in appropriate in vitro cellular models. Previously, a B19V genome of defined consensus sequence was designed, synthesized and cloned in a complete and functional form, able to replicate and produce infectious viral particles in a producer/amplifier cell system. Based on such a system, we have now designed and produced a derived B19V minigenome, reduced to a replicon unit. The genome terminal regions were maintained in a form able to sustain viral replication, while the internal region was clipped to include only the left-side genetic set, containing the coding sequence for the functional NS1 protein. Following transfection in UT7/EpoS1 cells, this minigenome still proved competent for replication, transcription and production of NS1 protein. Further, the B19V minigenome was able to complement B19-derived, NS1-defective genomes, restoring their ability to express viral capsid proteins. The B19V genome was thus engineered to yield a two-component system, with complementing functions, providing a valuable tool for studying viral expression and genetics, suitable to further engineering for purposes of translational research.
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Project description:Human parvovirus B19 is the only parvovirus known to be a human pathogen. The structure of recombinant B19-like particles has been determined to approximately 3.5-A resolution by x-ray crystallography and, to our knowledge, represents the first near-atomic structure of an Erythrovirus. The polypeptide fold of the major capsid protein VP2 is a "jelly roll" with a beta-barrel motif similar to that found in many icosahedral viruses. The large loops connecting the strands of the beta-barrel form surface features that differentiate B19 from other parvoviruses. Although B19 VP2 has only 26% sequence identity to VP3 of adeno-associated virus, 72% of the C(alpha) atoms can be aligned structurally with a rms deviation of 1.8 A. Both viruses require an integrin as a coreceptor, and conserved surface features suggest a common receptor-binding region.
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Project description:Noroviruses (NoVs) are the main pathogens responsible for sporadic and epidemic nonbacterial gastroenteritis, causing an estimated 219,000 deaths annually worldwide. There is no commercially available vaccine for NoVs, due partly to the difficulty in establishing NoV cell culture models. The histo-blood group antigen (HBGA) blocking assay is used extensively to assess the protective potential of candidate vaccine-elicited antibodies, but there is still no widely used cellular evaluation model. In this study, we have established a cell line-based NoV vaccine evaluation model through the construction of human α1,2-fucosyltransferase 2-overexpressing 293T (293T-FUT2) cell lines. The 293T-FUT2 cells stably expressed H type 2 and Lewis y antigens. Virus-like particles (VLPs) of the NoV prototype strain genogroup I.1 (GI.1) and the predominant strains GII.4 and GII.17 could attach to the cell line efficiently in a dose-dependent manner. Importantly, antisera against these NoV VLPs could inhibit the attachment of the VLPs, where the inhibitory effects measured by the attachment inhibition assay correlated significantly with the antibody levels determined by the HBGA blocking assay. Collectively, our attachment inhibition assay could serve as a surrogate neutralization assay for the evaluation of NoV vaccines at the cellular level.
| S-EPMC5795440 | biostudies-literature