Here we propose a strategy allowing implementing efficient and practicable large-scale seroepidemiological studies for Zika Virus (ZIKV). It combines screening by a commercial NS1 protein-based Zika ...IgG ELISA, and confirmation by a cytopathic effect-based virus neutralization test (CPE-based VNT). In post-epidemic samples from Martinique Island blood donors (a population with a dengue seroprevalence above 90%), this strategy allowed reaching specificity and sensitivity values over 98%. The CPE-based VNT consists of recording CPE directly under the optical microscope, which is easy to identify with ZIKV strain H/PF/2013 at day 5 pi. Overall, considered that CPE-based VNT is cost effective and widely automatable, the NS1 protein-based Zika IgG ELISA+CPE-based VNT combination strategy represents a convenient tool to expedite ZIKV seroprevalence studies.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Vaccinia virus polymerase holoenzyme is composed of three subunits: E9, the catalytic DNA polymerase subunit; D4, a uracil‐DNA glycosylase; and A20, a protein with no known enzymatic activity. ...The D4/A20 heterodimer is the DNA polymerase cofactor, the function of which is essential for processive DNA synthesis. The recent crystal structure of D4 bound to the first 50 amino acids of A20 (D4/A201–50) revealed the importance of three residues, forming a cation–π interaction at the dimerization interface, for complex formation. These are Arg167 and Pro173 of D4 and Trp43 of A20. Here, the crystal structures of the three mutants D4‐R167A/A201–50, D4‐P173G/A201–50 and D4/A201–50‐W43A are presented. The D4/A20 interface of the three structures has been analysed for atomic solvation parameters and cation–π interactions. This study confirms previous biochemical data and also points out the importance for stability of the restrained conformational space of Pro173. Moreover, these new structures will be useful for the design and rational improvement of known molecules targeting the D4/A20 interface.
The Vaccinia virus D4/A20 complex is the DNA polymerase cofactor. The heterodimer interface has been analysed using three new crystal structures of the complex in which key residues forming a cation–π interaction have been mutated.
Phlebotomine sand flies are known to transmit Leishmania, bacteria, and viruses that affect humans and animals in many countries worldwide. Sand fly-borne viruses belong mainly to the Phlebovirus, ...Vesiculovirus, and Orbivirus genera, and some of them are associated with outbreaks or sporadic human cases in the Mediterranean Europe. Up to now, Toscana virus is the only phlebovirus of medical importance identified in France. To study the diversity of the sand fly population living in the southeastern France, an entomological study was conducted from May to October, 2007. Most of the trapped sand flies belonged to Phlebotomus perniciosus (82.0%) and Sergentomyia minuta (17.3%) species; only three specimens were Phlebotomus ariasi. Molecular characterization of the P. perniciosus specimen based on the mitochondrial cytochrome b gene demonstrated different subpopulations living in the same areas. Most of the specimens belonged to the haplotypes pern01 and pern09, already described in France, but some belonged to original new haplotypes. The detection of one viral sequence clustering with Massilia/Granada virus, and of four sequences corresponding to two potential new phleboviruses (proposed names Olbia and Provencia viruses, respectively), revealed an unexpected diversity of phlebovirus species in France.
Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that causes epidemic fever, rash and polyarthralgia in Africa and Asia. Although it is known since the 1950s, new epidemiological and clinical ...features reported during the recent outbreak in the Indian Ocean can be regarded as the emergence of a new disease. Numerous severe forms of the infection have been described that put emphasis on the lack of efficient antiviral therapy. Among the virus-encoded enzymes, nsP2 constitutes an attractive target for the development of antiviral drugs. It is a multifunctional protein of approximately 90kDa with a helicase motif in the N-terminal portion of the protein while the papain-like protease activity resides in the C-terminal portion. The nsP2 proteinase is an essential enzyme whose proteolytic activity is critical for virus replication.
In this work, a recombinant CHIKV nsP2pro and a C-terminally truncated variant were expressed in Escherichia coli and purified by metal–chelate chromatography. The enzymatic properties of the proteinase were then determined using specific synthetic fluorogenic substrates. This study constitutes the first characterization of a recombinant CHIKV nsP2 cysteine protease, which may be useful for future drug screening.
Rift Valley fever virus, a phlebovirus endemic in Africa, causes serious diseases in ruminants and humans. Due to the high probability of new outbreaks and spread to other continents where competent ...vectors are present, vaccine development is an urgent priority as no licensed vaccines are available outside areas of endemicity. In this study, we evaluated in sheep the protective immunity induced by DNA vaccines encoding the extracellular portion of the Gn antigen which was either or not targeted to antigen-presenting cells. The DNA encoding untargeted antigen was the most potent at inducing IgG responses, although not neutralizing, and conferred a significant clinical and virological protection upon infectious challenge, superior to DNA vaccines encoding the targeted antigen. A statistical analysis of the challenge parameters supported that the anti-eGn IgG, rather than the T-cell response, was instrumental in protection. Altogether, this work shows that a DNA vaccine encoding the extracellular portion of the Gn antigen confers substantial-
-protective immunity in sheep, a natural host with high preclinical relevance, and provides some insights into key immune correlates useful for further vaccine improvements against the Rift Valley fever virus.
Dengue type 3 virus, Saint Martin, 2003-2004 Peyrefitte, Christophe N; Pastorino, Boris A M; Bessaud, Maël ...
Emerging infectious diseases,
05/2005, Letnik:
11, Številka:
5
Journal Article
Recenzirano
Odprti dostop
We describe the spread of a dengue virus during an outbreak in Saint Martin island (French West Indies) during winter 2003-2004. Dengue type 3 viruses were isolated from 6 patients exhibiting ...clinical symptoms. This serotype had not been detected on the island during the preceding 3 years. Genome sequence determinations and analyses showed a common origin with dengue type 3 viruses isolated in Martinique 2 years earlier.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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