Cellular origin and ultrastructure of membranes induced during poliovirus infection

TLDR

Poliovirus RNA replicative complexes associate with cytoplasmic membranous structures that accumulate during infection. The authors isolated virus‑induced membranes using a monoclonal antibody against protein 2C and biochemically showed that lysosomes, the trans‑Golgi network, and the ER contribute to these structures. Electron microscopy revealed double‑bilayer membranes enclosing cytosolic material, and immunolabeling showed viral proteins 2C and 3D co‑localize with cellular markers, supporting a role for autophagy or a related host process in membrane formation.

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.