A modified lysosomal organelle mediates nonlytic egress of reovirus.

Autor:	Fernández de Castro I; Cell Structure Laboratory, National Center for Biotechnology, Spanish National Research Council, Madrid, Spain., Tenorio R; Cell Structure Laboratory, National Center for Biotechnology, Spanish National Research Council, Madrid, Spain., Ortega-González P; Cell Structure Laboratory, National Center for Biotechnology, Spanish National Research Council, Madrid, Spain., Knowlton JJ; Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN.; Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA., Zamora PF; Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN.; Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA., Lee CH; Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA.; Center for Microbial Pathogenesis, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA., Fernández JJ; Department of Macromolecular Structures, National Center for Biotechnology, Spanish National Research Council, Madrid, Spain., Dermody TS; Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA.; Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA.; Center for Microbial Pathogenesis, UPMC Children's Hospital of Pittsburgh, Pittsburgh, PA., Risco C; Cell Structure Laboratory, National Center for Biotechnology, Spanish National Research Council, Madrid, Spain.
Jazyk:	angličtina
Zdroj:	The Journal of cell biology [J Cell Biol] 2020 Jul 06; Vol. 219 (7).
DOI:	10.1083/jcb.201910131
Abstrakt:	Mammalian orthoreoviruses (reoviruses) are nonenveloped viruses that replicate in cytoplasmic membranous organelles called viral inclusions (VIs) where progeny virions are assembled. To better understand cellular routes of nonlytic reovirus exit, we imaged sites of virus egress in infected, nonpolarized human brain microvascular endothelial cells (HBMECs) and observed one or two distinct egress zones per cell at the basal surface. Transmission electron microscopy and 3D electron tomography (ET) of the egress zones revealed clusters of virions within membrane-bound structures, which we term membranous carriers (MCs), approaching and fusing with the plasma membrane. These virion-containing MCs emerged from larger, LAMP-1-positive membranous organelles that are morphologically compatible with lysosomes. We call these structures sorting organelles (SOs). Reovirus infection induces an increase in the number and size of lysosomes and modifies the pH of these organelles from ∼4.5-5 to ∼6.1 after recruitment to VIs and before incorporation of virions. ET of VI-SO-MC interfaces demonstrated that these compartments are connected by membrane-fusion points, through which mature virions are transported. Collectively, our results show that reovirus uses a previously undescribed, membrane-engaged, nonlytic egress mechanism and highlights a potential new target for therapeutic intervention. (© 2020 Fernández de Castro et al.)
Databáze:	MEDLINE
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