Coxsackievirus infection in skeletal muscles of mice An electron microscopic study I. Cell- and nucleus alterations

Abstract

SummaryCell-and nucleus alterations of coxsackievirus A 1 infected striated muscles of newborn mice are described: The first signs of an infection are always found in the nucleus, where the chromatin becomes condensed at the periphery. Swelling of the perinuclear space is followed by the development of vacuoles and channels formed by the nuclear membrane. This membrane coates also deep invaginations into the lobed nucleus. Electron-light areas of the nucleus contain granular and fibrillar inclusions. Only after the beginning of nuclear alteration, cytoplasmic degeneration is noted, starting with vacuolisation of the ER and going on with the disintegration of the contractile material followed by the formation of islets of organelles (vacuoles, mitochondria etc.) in large areas of completely disorganized filaments. The last stages are characterized by complete nuclear breakdown, loss of sarcolemm and immigration of phagocytes. These observations are compared with those made by other authors in genetic muscle dystrophies. The mechanisms of the cellular damage are discussed.

Morphogenesis of the Nodamura virus in the larvae of the lepidopteranGalleria mellonella (L.)

“…The pathogenesis and morphogenesis of the Nodamura virus observed in the larvae of G. rnellonella are similar to those described for the picornaviruses of vertebrates (7,9,13,14,15) or of invertebrates (3,25,30). The difference resides mainly in the variety of the hosts, both vertebrates and invertebrates, and in the tissue sensitivity to the Nodamura virus.…”

“…Similar filaments have also been observed in muscle cells of mice infected with the Coxsackie A virus (9), but not in the hemocytes or moulting glands of the larvae of G. mellonella infected with the Nodamura virus nor in cells infected in vitro with vertebrate picornaviruses. I t is possible that they correspond to the contractile filaments arising from the disorganization of the fibers and fibrils or that this material is synthesized de novo under the influence of the viral genome (9). However, in the Nodamura virus-infected G. metloneUa the presence and progressive accumulation of this material inside the basal membranes, as well as its particular structure lend support to the second interpretation.…”

“…The nucleus does not seem to play as an important role as in the infection with some picornaviruses (2,7,8,9).…”

“…In a. mellonella the disorganization of muscular tissue corresponds to that observed in newborn mice infected with the Nodamura virus (20) or the Coxsackie viruses (9).…”

Two Membrane-Associated Regions within the Nodamura Virus RNA-Dependent RNA Polymerase Are Critical for both Mitochondrial Localization and RNA Replication

“…The source of the membranes varies with the virus: many viral RCs are associated with modified membranes derived from the endoplasmic reticulum (ER), including members of the arteri-, bromo-, corona-, flavi-, and picornavirus families (20)(21)(22)(23)(24)(25)(26)(27)(28)(29). However, the RCs of other virus families localize to membranes derived from other organelles, including chloroplasts and peroxisomes (tombusviruses), endosomes and lysosomes (togaviruses), and mitochondria (tombus-and nodaviruses) (30)(31)(32)(33)(34).…”