| 1. |
- Lozach, Pierre-Yves, et al.
(författare)
-
Entry of bunyaviruses into mammalian cells
- 2010
-
Ingår i: Cell host & microbe. - : Elsevier BV. - 1934-6069 .- 1931-3128. ; 7:6, s. 488-499
-
Tidskriftsartikel (refereegranskat)abstract
- The Bunyaviridae constitute a large family of enveloped animal viruses, many members of which cause serious diseases. However, early bunyavirus-host cell interactions and entry mechanisms remain largely uncharacterized. Investigating Uukuniemi virus, a bunyavirus of the genus Phlebovirus, we found that virus attachment to the cell surface was specific but inefficient, with 25% of bound viruses being endocytosed within 10 min, mainly via noncoated vesicles. The viruses entered Rab5a+ early endosomes and, subsequently, Rab7a+ and LAMP-1+ late endosomes. Acid-activated penetration, occurring 20-40 min after internalization, required maturation of early to late endosomes. The pH threshold for viral membrane fusion was 5.4, and entry was sensitive to temperatures below 25 degrees C. Together, our results indicate that Uukuniemi virus penetrates host cells by acid-activated membrane fusion from late endosomal compartments. This study also highlights the importance of the degradative branch of the endocytic pathway in facilitating entry of late-penetrating viruses.
|
|
| 2. |
- Sotiriou, Georgios A., et al.
(författare)
-
Hybrid, Silica-Coated, Janus-Like Plasmonic-Magnetic Nanoparticles
- 2011
-
Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 23:7, s. 1985-1992
-
Tidskriftsartikel (refereegranskat)abstract
- Hybrid plasmonic-magnetic nanoparticles possess properties that are attractive in bioimaging, targeted drug delivery, in vivo diagnosis, and therapy. The stability and toxicity, however, of such nanoparticles challenge their safe use today. Here, biocompatible, SiO(2)-coated, Janus-like Ag/Fe(2)O(3) nanoparticles are prepared by one-step, scalable flame aerosol technology. A nanothin SiO(2) shell around these multifunctional nanoparticles leaves intact their morphology and magnetic and plasmonic properties but minimizes the release of toxic Ag(+) ions from the nanosilver surface and its direct contact with live cells. Furthermore, this silica shell hinders flocculation and allows for easy dispersion of such nanoparticles in aqueous and biological buffer (PBS) solutions without any extra fiinctionalization step. As a result, these hybrid particles exhibited no cytotoxicity during bioimaging and remained stable in suspension with no signs of agglomeration and sedimentation or settling. Their performance as biomarkers was explored by selectively binding them with live tagged Raji and HeLa cells enabling their detection under dark-field illumination. Therefore, these SiO(2)-coated Ag/Fe(2)O(3) nanoparticles do not exhibit the limiting physical properties of each individual component but retain their desired functionalities facilitating thus, the safe use of such hybrid nanoparticles in bioapplications.
|
|
| 3. |
- Uckeley, Zina M., et al.
(författare)
-
Quantitative Proteomics of Uukuniemi Virus-host Cell Interactions Reveals GBF1 as Proviral Host Factor for Phleboviruses
- 2019
-
Ingår i: Molecular & Cellular Proteomics. - : American Society for Biochemistry and Molecular Biology. - 1535-9476 .- 1535-9484. ; 18:12, s. 2401-2417
-
Tidskriftsartikel (refereegranskat)abstract
- Novel tick-borne phleboviruses in the Phenuiviridae family, which are highly pathogenic in humans and all closely related to Uukuniemi virus (UUKV), have recently emerged on different continents. How phleboviruses assemble, bud, and exit cells remains largely elusive. Here, we performed high-resolution, label-free mass spectrometry analysis of UUKV immunoprecipitated from cell lysates and identified 39 cellular partners interacting with the viral envelope glycoproteins. The importance of these host factors for UUKV infection was validated by silencing each host factor by RNA interference. This revealed Golgi-specific brefeldin A-resistance guanine nucleotide exchange factor 1 (GBF1), a guanine nucleotide exchange factor resident in the Golgi, as a critical host factor required for the UUKV life cycle. An inhibitor of GBF1, Golgicide A, confirmed the role of the cellular factor in UUKV infection. We could pinpoint the GBF1 requirement to UUKV replication and particle assembly. When the investigation was extended to viruses from various positive and negative RNA viral families, we found that not only phleboviruses rely on GBF1 for infection, but also Flavi-, Corona-, Rhabdo-, and Togaviridae. In contrast, silencing or blocking GBF1 did not abrogate infection by the human adenovirus serotype 5 and immunodeficiency retrovirus type 1, the replication of both requires nuclear steps. Together our results indicate that UUKV relies on GBF1 for viral replication, assembly and egress. This study also highlights the proviral activity of GBF1 in the infection by a broad range of important zoonotic RNA viruses. Ticks are important vectors of infectious emerging diseases and tick-borne phleboviruses represent a growing threat to humans globally. We employed here a high-resolution, label-free mass spectrometry and RNA interference screen approach to reveal the host cell protein GBF1 as a proviral factor, not only for tick-borne phleboviruses, but also for many other important zoonotic RNA viruses. This study lays the basis for the development of innovative antiviral strategies against a broad range of human pathogenic viruses.
|
|
