Search results for "Viruses"
showing 10 items of 1182 documents
Highly efficient transport of carboxyfluorescein diacetate succinimidyl ester into COS7 cells using human papillomavirus-like particles
2003
AbstractHuman papillomavirus virus-like particles (VLPs) have recently been used to deliver genes into mammalian cells in vitro and in vivo. Here, we investigated whether VLPs may serve as an efficient carrier of low molecular weight compounds (e.g. hormones, vitamins, peptides etc.) into cells. COS7 cells were incubated with recombinant HPV-16L1/L2 VLPs labelled with the fluorescence dye carboxyfluorescein diacetate succinimidyl ester. Using flow cytometry, we demonstrate that labelled VLPs can specifically bind to the cell surface followed by their complete internalisation. Our results indicate that VLPs are promising vehicles for highly efficient delivery of low molecular weight compound…
HPV in semen: evaluation of the link among infection, sperm parameters and viral genome integration
2016
Human papillomaviruses (HPVs) are agents of the most common sexually transmitted diseases. Both in men and in women, HPVs cause a variety of clinical symptoms ranging from warts to cancer. It has been shown that infection with oncogenic HPV is the major cause of development of cervical cancer in women and less frequently of penile cancers in men. HPV infects epithelial cells and can bind other cell types. Its presence in semen is widely known, but the effects on fertility and reproductive function are still controversial. Partners of women with high-grade squamous intraepithelial lesions were enrolled. From each subject seminal parameters were evaluated. HPV was detected and genotyped both …
AAV Vector–mediated RNAi of Mutant Huntingtin Expression Is Neuroprotective in a Novel Genetic Rat Model of Huntington's Disease
2008
We report the characterization of a new rapid-onset model of Huntington's disease (HD) generated by adeno-associated virus (AAV) vector–mediated gene transfer of N-terminal huntingtin (htt) constructs into the rat striatum. Expression of exon 1 of mutant htt containing 70 CAG repeats rapidly led to neuropathological features associated with HD. In addition, we report novel data relating to neuronal transduction of AAV vectors that modulated the phenotype observed in this model. Quantitative reverse transcriptase–polymerase chain reaction (RT–PCR) revealed that AAV vector–mediated expression in the striatum increased by >100-fold as compared to the endogenous htt level. Moreover, AAV vectors…
Monitoring human parvovirus B19 virus-like particles and antibody complexes in solution by fluorescence correlation spectroscopy
2004
AbstractFluorescence correlation spectroscopy (FCS) was used in monitoring human parvovirus B19 virus-like particle (VLP) antibody complexes from acute phase and pastimmunity serum samples. The Oregon Green 488-labeled VLPs gave an average diffusion coefficient of 1.7x10exp-7 cm(2)s(-1) with an apparent hydrodynamic radius of 14 nm. After incubation of the fluorescent VLPs with an acute phase serum sample, the mobility information obtained from the fluorescence intensity fluctuation by autocorrelation analysis showed an average diffusion coefficient of 1.5x10exp-8 cm(2)s(-1), corresponding to an average radius of 157 nm. In contrast, incubation of the fluorescent VLPs with a pastimmunity se…
Closely Related Archaeal Haloarcula hispanica Icosahedral Viruses HHIV-2 and SH1 Have Nonhomologous Genes Encoding Host Recognition Functions
2012
Studies on viral capsid architectures and coat protein folds have revealed the evolutionary lineages of viruses branching to all three domains of life. A widespread group of icosahedral tailless viruses, the PRD1-adenovirus lineage, was the first to be established. A double -barrel fold for a single major capsid protein is characteristic of these viruses. Similar viruses carrying genes coding for two major capsid proteins with a more complex structure, such as Thermus phage P23-77 and haloarchaeal virus SH1, have been isolated. Here, we studied the host range, life cycle, biochemical composition, and genomic sequence of a new isolate, Haloarcula hispanica icosahedral virus 2 (HHIV-2), which…
Mutilation of RNA phage Qβ virus-like particles: from icosahedrons to rods
2000
Icosahedral virus-like particles (VLPs) of RNA phage Qbeta are stabilized by four disulfide bonds of cysteine residues 74 and 80 within the loop between beta-strands F and G (FG loop) of the monomeric subunits, which determine the five-fold and quasi-six-fold symmetry contacts of the VLPs. In order to reduce the stability of Qbeta VLPs, we mutationally converted the amino acid stretch 76-ANGSCD-81 within the FG loop into the 76-VGGVEL-81 sequence. It led to production in Escherichia coli cells of aberrant rod-like Qbeta VLPs, along with normal icosahedral capsids. The length of the rod-like particles exceeded 4-30 times the diameter of icosahedral Qbeta VLPs.
Viral evolution and Immune responses
2019
Antiviral responses are activated rapidly after viral infection in order to control and prevent dissemination of the virus. Different pathways are activated in the immune system, including innate and adaptive responses. On the other hand, viruses have evolved specifi c strategies to evade these responses. Due to the high viral evolutionary rates, escape variants can emerge and spread fast in the population. The co-evolution between viruses and their host is a constant arms race, and is of special interest to understand the viral escape mechanisms that may guide the future development of antiviral treatments and vaccines.
Recombinant virus-like particles as a carrier of B- and T-cell epitopes of hepatitis C virus (HCV)
2005
The major aim of the project was the development of virus-like particles (VLP) displaying B- and T-cell epitopes of hepatitis C virus (HCV) proteins. To this end, hepatitis B virus core (HBc) particles were used as a carrier of HCV epitopes. Fragments of HCV genes encoding core (aa 98) and NS3 (aa 155) proteins were fused to the 3' terminus of the truncated HBV core gene. All recombinant plasmids led to relatively high levels of expression of chimeric proteins in E. coli, which resulted in the formation of complete "mature" VLP. Chimeric HBc/HCV VLPs were purified by combination of gel filtration and sucrose gradient centrifugation, and used for immunogenicity studies in mice. All variants …
Nasal immunization of mice with a rotavirus DNA vaccine that induces protective intestinal IgA antibodies
2004
International audience; DNA vaccination using a plasmid encoding the rotavirus inner capsid VP6 has been explored in the mouse model of rotavirus infection. BALB/c mice were immunized with a VP6 DNA vaccine by the intramuscular, nasal and oral routes. VP6 DNA vaccination by the nasal and oral routes induced the production of anti-VP6 IgA antibodies by intestinal lymphoid cells. Intramuscular DNA injection stimulated the production of serum anti-VP6 IgG but not serum anti-VP6 IgA antibodies. Protection against shedding of rotaviruses in stools after oral challenge with the murine EDIM rotavirus strain was investigated in the immunized mice. A significant reduction in the level of rotavirus a…
An L2 SUMO interacting motif is important for PML localization and infection of human papillomavirus type 16
2014
Summary Human papillomaviruses (HPV) induce warts and cancers on skin and mucosa. The HPV16 capsid is composed of the proteins L1 and L2. After cell entry and virus disassembly, the L2 protein accompanies the viral DNA to promyelocytic leukaemia nuclear bodies (PML-NBs) within the host nuclei enabling viral transcription and replication. Multiple components of PML-NBs are regulated by small ubiquitin-like modifiers (SUMOs) either based on covalent SUMO modification (SUMOylation), or based on non-covalent SUMO interaction via SUMO interacting motifs (SIMs). We show here that the HPV16 L2 comprises at least one SIM, which is crucial for the L2 interaction with SUMO2 in immunoprecipitation and…