Capsid-deficient alphaviruses generate propagative infectious microvesicles at the plasma membrane.

Capsid-deficient alphaviruses generate propagative infectious microvesicles at the plasma membrane. Cell Mol Life Sci. 2016 Apr 27; Authors: Ruiz-Guillen M, Gabev E, Quetglas JI, Casales E, Ballesteros-Briones MC, Poutou J, Aranda A, Martisova E, Bezunartea J, Ondiviela M, Prieto J, Hernandez-Alcoceba R, Abrescia NG, Smerdou C Abstract Alphavirus budding is driven by interactions between nucleocapsids assembled in the cytoplasm and envelope proteins present at the plasma membrane. So far, the expression of capsid and envelope proteins in infected cells has been considered an absolute requirement for alphavirus budding and propagation. In the present study, we show that Semliki Forest virus and Sindbis virus lacking the capsid gene can propagate in mammalian and insect cells. This propagation is mediated by the release of infectious microvesicles (iMVs), which are pleomorphic and have a larger size and density than wild-type virus. iMVs, which contain viral RNA inside and viral envelope proteins on their surface, are released at the plasma membrane and infect cells using the endocytic pathway in a similar way to wild-type virus. iMVs are not pathogenic in immunocompetent mice when injected intravenously, but can infect different organs like lungs and heart. Finally, we also show that alphavirus genomes without capsid can mediate the propagation of heterologous genes, making these vectors potentially interesting for gene therapy or vac...
Source: Cellular and Molecular Life Sciences : CMLS - Category: Cytology Authors: Tags: Cell Mol Life Sci Source Type: research