Search results for "capsid"

2021

Parvoviruses are small single-stranded (ss) DNA viruses, which replicate in the nucleoplasm and affect both the structure and function of the nucleus. The nuclear stage of the parvovirus life cycle starts at the nuclear entry of incoming capsids and culminates in the successful passage of progeny capsids out of the nucleus. In this review, we will present past, current, and future microscopy and biochemical techniques and demonstrate their potential in revealing the dynamics and molecular interactions in the intranuclear processes of parvovirus infection. In particular, a number of advanced techniques will be presented for the detection of infection-induced changes, such as DNA modification…

2020

We report that several viruses from the human enterovirus group B cause massive vimentin rearrangements during lytic infection. Comprehensive studies suggested that viral protein synthesis was triggering the vimentin rearrangements. Blocking the host cell vimentin dynamics with β, β'-iminodipropionitrile (IDPN) did not significantly affect the production of progeny viruses and only moderately lowered the synthesis of structural proteins such as VP1. In contrast, the synthesis of the nonstructural proteins 2A, 3C, and 3D was drastically lowered. This led to attenuation of the cleavage of the host cell substrates PABP and G3BP1 and reduced caspase activation, leading to prolonged cell surviva…

Parvovirus capsid disorders cholesterol-rich membranes.

2008

In this study canine parvovirus, CPV, was found to induce disorder in DPPC:cholesterol membranes in acidic conditions. This acidicity-induced fluidizing effect is suggested to originate from the N-terminus of the viral capsid protein VP1. In accordance with the model membrane studies, a fluidizing effect was seen also in the endosomal membranes during CPV infection implying an important functional role of the fluidization in the endocytic entry of the virus.

Serological Follow-Up Study Indicates High Seasonal Coronavirus Infection and Reinfection Rates in Early Childhood

2022

Seasonal human coronaviruses (HCoVs) cause respiratory infections, especially in children. Currently, the knowledge on early childhood seasonal coronavirus infections and the duration of antibody levels following the first infections is limited. Here we analyzed serological follow-up samples to estimate the rate of primary infection and reinfection(s) caused by seasonal coronaviruses in early childhood. Serum specimens were collected from 140 children at ages of 13, 24, and 36 months (1, 2, and 3 years), and IgG antibody levels against recombinant HCoV nucleoproteins (N) were measured by enzyme immunoassay (EIA). Altogether, 84% (118/140) of the children were seropositive for at least one s…

Fibronectin-binding nanoparticles for intracellular targeting addressed by B. burgdorferi BBK32 protein fragments.

2011

Virus-like particles (VLPs) are created by the self-assembly of multiple copies of envelope and/or capsid proteins from many viruses, mimicking the conformation of a native virus. Such noninfectious nanostructures are mainly used as antigen-presenting platforms, especially in vaccine research; however, some of them recently were used as scaffolds in biotechnology to produce targeted nanoparticles for intracellular delivery. This study demonstrates the creation of fusion VLPs using hepatitis B core protein-based system maintaining a fibronectin-binding property from B. burgdorferi BBK32 protein, including the evidence of particles’ transmission to BHK-21 target cells via caveolae/rafts endoc…

Effectiveness of Toki s criteria and determination of variables for identification of HPV L1 protein in oral lesions

2013

Objectives: To evaluate the effectiveness of Toki's criteria in identifying the HPV L1 protein in oral lesions with the use of immunohistochemistry (IHC) and to determine which criteria optimize such identification. Study Design: Retrospective study of 277 cases diagnosed as HPV lesions at 22 years. Tests of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), kappa coefficients, and chi 2 values, as well as two logistic regression analyses ( (p≤0.05), were conducted. Results: Of the lesions studied, 96.4% (267 of 277) were positive for HPV using Toki's criteria and 28.5% (79 of 277) were positive for L1 by IHC. Toki's criteria showed sensitivity=93.67…

SARS‐CoV‐2 N‐antigenemia in critically ill adult COVID‐19 patients: Frequency and association with inflammatory and tissue‐damage biomarkers

2021

Abstract The current study aimed at characterizing the dynamics of SARS‐CoV‐2 nucleocapsid (N) antigenemia in a cohort of critically ill adult COVID‐19 patients and assessing its potential association with plasma levels of biomarkers of clinical severity and mortality. Seventy‐three consecutive critically ill COVID‐19 patients (median age, 65 years) were recruited. Serial plasma (n = 340) specimens were collected. A lateral flow immunochromatography assay and reverse‐transcription polymerase chain reaction (RT‐PCR) were used for SARS‐CoV‐2 N protein detection and RNA quantitation and in plasma, respectively. Serum levels of inflammatory and tissue‐damage biomarkers in paired specimens were …

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…

Molecular Cloning, Expression, Self-Assembly, Antigenicity, and Seroepidemiology of a Genogroup II Norovirus Isolated in France

2003

ABSTRACT Virus-like particles of Dijon171/96 virus, a genogroup II norovirus, were expressed in a baculovirus system and were used for a seroepidemiological study of 1,078 age-stratified human sera collected in Dijon, France. The results showed a seroprevalence of 74.1%. Furthermore, we showed that murine antibodies generated against recombinant Dijon171/96 virus, and human antibodies recognized discontinuous epitopes on the particles.

Human papillomavirus antibody responses among patients with incident cervical carcinoma

1997

The human papillomavirus (HPV) is recognized as a major cause of cervical cancer precursor lesions. HPV serology is a key method in the continuing elucidation of the importance of HPV exposure for cancer development and in predicting HPV-associated diseases. To extend previous HPV serological studies on cervical cancer, serum samples from a consecutive series of 216 women with incident untreated cervical carcinoma and 243 age- and sex-matched healthy blood donors were evaluated for the presence of antibodies against HPV capsids, a marker of past or present HPV exposure, as well as against several cervical cancer-associated defined HPV epitopes. Among the capsid antibody responses, HPV type …