Cellular origin and ultrastructure of membranes induced during poliovirus infection

Abstract

Poliovirus RNA replicative complexes are associated with cytoplasmic membranous structures that accumulate during viral infection. These membranes were immunoisolated by using a monoclonal antibody against the viral nonstructural protein 2C. Biochemical analysis of the isolated membranes revealed that several organelles of the host cell (lysosomes, trans-Golgi stack and trans-Golgi network, and endoplasmic reticulum) contributed to the virus-induced membranous structures. Electron microscopy of infected cells preserved by high-pressure freezing revealed that the virus-induced membranes contain double lipid bilayers that surround apparently cytosolic material. Immunolabeling experiments showed that poliovirus proteins 2C and 3D were localized to the same membranes as the cellular markers tested. The morphological and biochemical data are consistent with the hypothesis that autophagy or a similar host process is involved in the formation of the poliovirus-induced membranes.

A Guide to Viral Inclusions, Membrane Rearrangements, Factories, and Viroplasm Produced During Virus Replication

“…The positive-stranded RNA viruses encode nonstructural proteins (NSP) that cause proliferation and modification of membranes of the host secretory pathway. The membranes are thought to provide a physical framework or ''replication complex'' that concentrates the cellular and viral components required for virus replication (Bienz et al, 1987;Egger et al, 2002;Froshauer et al, 1988;Gazina et al, 2002;Magliano et al, 1998;Schlegel et al, 1996;van der Meer et al, 1998). Assembly of the replicase on membranes, rather than the cytosol, may also help viruses evade host defence pathways that monitor cells for double-stranded RNA (dsRNA) intermediates indicative of virus replication.…”

“…The accumulation of large numbers of densely packed membrane vesicles in the cytoplasm is characteristic of a picornavirus infection (Bienz et al, 1983(Bienz et al, , 1987Cho et al, 1994;Dales et al, 1965a;Schlegel et al, 1996;Stuart and Fogh, 1961;Suhy et al, 2000). Studies have suggested that vesicles induced by Poliovirus are derived from the ER, either from COPII-coated vesicles or from ER-derived autophagic double-membraned vacuoles (Bienz et al, 1987;Jackson et al, 2005;Rust et al, 2001;Schlegel et al, 1996;Suhy et al, 2000). However, the detection of ER, Golgi, and lysosomal markers in membranes induced at later stages of infection by Poliovirus suggests that more than one organelle may contribute membranes to the replication complex (Schlegel et al, 1996).…”

“…Studies have suggested that vesicles induced by Poliovirus are derived from the ER, either from COPII-coated vesicles or from ER-derived autophagic double-membraned vacuoles (Bienz et al, 1987;Jackson et al, 2005;Rust et al, 2001;Schlegel et al, 1996;Suhy et al, 2000). However, the detection of ER, Golgi, and lysosomal markers in membranes induced at later stages of infection by Poliovirus suggests that more than one organelle may contribute membranes to the replication complex (Schlegel et al, 1996). In interpreting these studies, it is important to consider if the vesicles observed are involved in replication, or if they represent a bystander response to virus infection.…”

Membrane Origin for Autophagy

“…Factors of the poliovirus RNA-replication complex localize to doublemembrane vesicles that are derived from the ER by the action of viral proteins 2BC and 3A by a mechanism that excludes resident host proteins (Schlegel et al, 1996;Suhy et al, 2000). Importantly, these structures contain LC3/Atg8 and are highlighted with the fluorophore monodansylcadaverine, a dye that specifically stains autophagosomes (Jackson et al, 2005).…”

Rna Viruses Redirect Host Factors to Better Amplify Their Genome

“…RNA synthesis of HCV occurs on membranes of the ER or on a membranous matrix designated membranous web (Moradpour et al, 2003) or lipid raft (detergent-resistant membrane) (Gao et al, 2004). Poliovirus infection leads to the appearance of greatly rearranged vesiculated membranes (Suhy et al, 2000), and poliovirus RNA replication occurs on membranes that contain markers of lysosomes, the Golgi apparatus, and the ER (Egger et al, 2000;Schlegel et al, 1996).…”