Resistance analysis of an antibody that selectively inhibits dengue virus serotype-1

10.1016/j.antiviral.2012.06.010Antiviral Research953216-223ARSR

Release of Dengue Virus Genome Induced by a Peptide Inhibitor

10.1371/journal.pone.0050995PLoS ONE711e5099

A highly potent human antibody neutralizes dengue virus serotype 3 by binding across three surface proteins

10.1038/ncomms7341Nature Communications

Culture-independent approaches for studying viruses from hypersaline environments

Hypersaline close-to-saturation environments harbor an extremely high concentration of virus-like particles, but the number of haloviruses isolated so far is still very low. Haloviruses can be directly studied from natural samples by using different culture-independent techniques that include transmission electron microscopy, pulsed-field gel electrophoresis, and different metagenomic approaches. Here, we review the findings of these studies, with a main focus on the metagenomic approaches. The analysis of bulk viral nucleic acids directly retrieved from the environment allows estimations of viral diversity, activity, and dynamics and tentative host assignment. Results point to a diverse and active viral community in constant interplay with its hosts and to a “hypersalineness” quality common to viral assemblages present in hypersaline environments that are thousands of kilometers away from each other.Our work on halophilic viral assemblages has been funded by the projects CGL2006-12714-CO2-01, CGL2006-12714-CO2-02, CGL2009-12651-C02-01, and CGL2009-12651-C02-02 from the Spanish Ministry of Science and Innovation that include funds from the European Community (FEDER funding) and by the project ACOMP/2009/155 from the Generalitat Valenciana

The structural basis for serotype-specific neutralization of dengue virus by a human antibody

10.1126/scitranslmed.3003888Science Translational Medicine4139

First insights into the entry process of hyperthermophilic archaeal viruses.

International audienceA decisive step in a virus infection cycle is the recognition of a specific receptor present on the host cell surface, subsequently leading to the delivery of the viral genome into the cell interior. Until now, the early stages of infection have not been thoroughly investigated for any virus infecting hyperthermophilic archaea. Here, we present the first study focusing on the primary interactions between the archaeal rod-shaped virus Sulfolobus islandicus rod-shaped virus 2 (SIRV2) (family Rudiviridae) and its hyperthermoacidophilic host, S. islandicus. We show that SIRV2 adsorption is very rapid, with the majority of virions being irreversibly bound to the host cell within 1 min. We utilized transmission electron microscopy and whole-cell electron cryotomography to demonstrate that SIRV2 virions specifically recognize the tips of pilus-like filaments, which are highly abundant on the host cell surface. Following the initial binding, the viral particles are found attached to the sides of the filaments, suggesting a movement along these appendages toward the cell surface. Finally, we also show that SIRV2 establishes superinfection exclusion, a phenomenon not previously described for archaeal viruses

Characterization of ecologically diverse viruses infecting co-occurring strains of cosmopolitan hyperhalophilic bacteroidetes

Hypersaline environments close to saturation harbor the highest density of virus-like particles reported for aquatic systems as well as low microbial diversity. Thus, they offer unique settings for studying virus-host interactions in nature. However, no viruses have been isolated so far infecting the two most abundant inhabitants of these systems (that is, the euryarchaeon Haloquadratum walsbyi and the bacteroidetes Salinibacter ruber). Here, using three different co-occurring strains, we have isolated eight viruses infecting the ubiquitous S. ruber that constitute three new different genera (named as 'Holosalinivirus', 'Kryptosalinivirus' and 'Kairosalinivirus') according to their genomic traits, different host range, virus-host interaction capabilities and abundances in natural systems worldwide. Furthermore, to get a more complete and comprehensive view of S. ruber virus assemblages in nature, a microcosm experiment was set with a mixture of S. ruber strains challenged with a brine virus concentrate, and changes of viral populations were monitored by viral metagenomics. Only viruses closely related to kairosalinivirus (strictly lytic and wide host range) were enriched, despite their low initial abundance in the natural sample. Metagenomic analyses of the mesocosms allowed the complete recovery of kairosalinivirus genomes using an ad hoc assembly strategy as common viral metagenomic assembly tools failed despite their abundance, which underlines the limitations of current approaches. The increase of this type of viruses was accompanied by an increase in the diversity of the group, as shown by contig recruitment. These results are consistent with a scenario in which host range, not only virus and host abundances, is a key factor in determining virus fate in nature.This research was supported by the Spanish Ministry of Economy projects CLG2015_66686-C3-1 (to JA) and CLG2015_66686-C3-3 (to RRM), which were also supported with European Regional Development Fund (FEDER) funds