Search results for "Parvovirus B19"
showing 10 items of 27 documents
Parvovirus B19V Nonstructural Protein NS1 Induces Double-Stranded Deoxyribonucleic Acid Autoantibodies and End-Organ Damage in Nonautoimmune Mice
2018
Abstract Background Viral infection is implicated in development of autoimmunity. Parvovirus B19 (B19V) nonstructural protein, NS1, a helicase, covalently modifies self double-stranded deoxyribonucleic acid (dsDNA) and induces apoptosis. This study tested whether resulting apoptotic bodies (ApoBods) containing virally modified dsDNA could induce autoimmunity in an animal model. Methods BALB/c mice were inoculated with (1) pristane-induced, (2) B19V NS1-induced, or (3) staurosporine-induced ApoBods. Serum was tested for dsDNA autoantibodies by Crithidia luciliae staining and enzyme-linked immunosorbent assay. Brain, heart, liver, and kidney pathology was examined. Deposition of self-antigens…
Extinct type of human parvovirus B19 persists in tonsillar B cells
2017
Parvovirus B19 (B19V) DNA persists lifelong in human tissues, but the cell type harbouring it remains unclear. We here explore B19V DNA distribution in B, T and monocyte cell lineages of recently excised tonsillar tissues from 77 individuals with an age range of 2–69 years. We show that B19V DNA is most frequent and abundant among B cells, and within them we find a B19V genotype that vanished from circulation >40 years ago. Since re-infection or re-activation are unlikely with this virus type, this finding supports the maintenance of pathogen-specific humoral immune responses as a consequence of B-cell long-term survival rather than continuous replenishment of the memory pool. Moreover, we …
Increased seroprevalence of parvovirus B 19 IgG in complex regional pain syndrome is not associated with antiendothelial autoimmunity
2005
The etiology of complex regional pain syndrome (CRPS) is unclear yet. Recently autoantibodies and antecedent viral infections have been discussed to be involved in the pathogenesis of CRPS. We investigated sera from 39 CRPS patients and healthy controls for parvovirus B19 IgG and the occurrence of antiendothelial autoantibodies (AECA). CRPS patients showed a higher seroprevalence of parvovirus B19 IgG than controls (p < 0.01). All CRPS 2 patients were positive. 10.2% of the CRPS patients and 10.0% of the controls had AECA (n.s.) and AECA were not associated with parvovirus B19 seropositivity. Our findings suggest the involvement of parvovirus B19, but not autoantibody-mediated endothelial c…
T helper cell-mediated interferon-gamma expression after human parvovirus B19 infection: persisting VP2-specific and transient VP1u-specific activity.
2005
SummaryHuman parvovirus B19 is a small non-enveloped DNA virus with an icosahedral capsid consisting of proteins of only two species, the major protein VP2 and the minor protein VP1. VP2 is contained within VP1, which has an additional unique portion (VP1u) of 227 amino acids. We determined the ability of eukaryotically expressed parvovirus B19 virus-like particles consisting of VP1 and VP2 in the ratio recommended for vaccine use, or of VP2 alone, to stimulate, in an HLA class II restricted manner, peripheral blood mononuclear cells (PBMC) to proliferate and to secrete interferon gamma (IFN-γ) and interleukin (IL)-10 cytokines among recently and remotely B19 infected subjects. PBMC reactiv…
Purification and analysis of polyhistidine-tagged human parvovirus B19 VP1 and VP2 expressed in insect cells
2008
Human parvovirus B19 is an autonomously replicating human pathogen with a specific tropism for human erythroid progenitor cells. There is an interest in producing empty nucleocapsids of B19 as they can be used as tools in molecular biology and diagnostics. Native B19 virus particles are formed from two structural viral proteins, VP1 and VP2. The VP2 protein alone is able to self assemble and consequently form virus-like particles (VLPs) in heterologous expression systems. Purification of recombinant VLPs has been conducted using various traditional methods. These include laborious and time-consuming, e.g. cesium chloride or sucrose gradient ultracentrifugation steps, allowing limited workin…
Biosensor Analysis of β2-Glycoprotein I–Reactive Autoantibodies: Evidence for Isotype-Specific Binding and Differentiation of Pathogenic from Infecti…
2007
Abstract Background: For the laboratory diagnosis of the antiphospholipid syndrome (APS) we developed a biosensor with the ability to distinguish between disease-relevant anti-β2-glycoprotein I (β2GPI) autoantibodies (anti-β2GPI) and pathogen-specific β2GPI cross-reactive antibodies that occur transiently during infections. Methods: We used a surface plasmon resonance (SPR) biosensor device. For the detection of anti-β2GPI in serum samples, affinity-purified human β2GPI was covalently attached to a functionalized n-alkanethiol self-assembling monolayer on the biosensor chip. After verifying the specificity of the biosensor system with a panel of monoclonal antibodies to β2GPI, we analyzed s…
Risk factors associated with adverse fetal outcomes in pregnancies affected by Coronavirus disease 2019 (COVID-19): a secondary analysis of the WAPM …
2020
Abstract Objectives To evaluate the strength of association between maternal and pregnancy characteristics and the risk of adverse perinatal outcomes in pregnancies with laboratory confirmed COVID-19. Methods Secondary analysis of a multinational, cohort study on all consecutive pregnant women with laboratory-confirmed COVID-19 from February 1, 2020 to April 30, 2020 from 73 centers from 22 different countries. A confirmed case of COVID-19 was defined as a positive result on real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of nasal and pharyngeal swab specimens. The primary outcome was a composite adverse fetal outcome, defined as the presence of either abortion (pre…
Parvovirus B19 nonstructural protein-induced damage of cellular DNA and resultant apoptosis.
2010
Parvovirus B19 is a widespread virus with diverse clinical presentations. The viral nonstructural protein, NS1, binds to and cleaves the viral genome, and induces apoptosis when transfected into nonpermissive cells, such as hepatocytes. We hypothesized that the cytotoxicity of NS1 in such cells results from chromosomal DNA damage caused by the DNA-nicking and DNA-attaching activities of NS1. Upon testing this hypothesis, we found that NS1 covalently binds to cellular DNA and is modified by PARP, an enzyme involved in repairing single-stranded DNA nicks. We furthermore discovered that the DNA nick repair pathway initiated by poly(ADPribose)polymerase and the DNA repair pathways initiated by …
Parvovirus B19 Genotype Specific Amino Acid Substitution in NS1 Reduces the Protein's Cytotoxicity in Culture
2010
A clinical association between idiopathic liver disease and parvovirus B19 infection has been observed. Fulminant liver failure, not associated with other liver-tropic viruses, has been attributed to B19 in numerous reports, suggesting a possible role for B19 components in the extensive hepatocyte cytotoxicity observed in this condition. A recent report by Abe and colleagues (Int J Med Sci. 2007;4:105-9) demonstrated a link between persistent parvovirus B19 genotype I and III infection and fulminant liver failure. The genetic analysis of isolates obtained from these patients demonstrated a conservation of key amino acids in the nonstructural protein 1 (NS1) of the disease-associated genotyp…