Enhanced intracellular calcium concentration during poliovirus infection

Abstract

The infection of human fibroblasts by poliovirus leads to a notable increase in the intracellular calcium concentration, [Ca2؉ ] i , measured by microfluorimetry or by flow cytometry. [Ca 2؉ ] i increases from 2 to 3 h postinfection, and by the fifth hour there is a 5-to 10-fold increase in [Ca 2؉ ] i . At this time postinfection there is active viral protein synthesis. The modifications in [Ca 2؉ ] i are not observed in the presence of cycloheximide, guanidine, or Ro 09-0179, indicating that virus gene expression is required for the increase in [Ca 2؉ ] i . Attempts to identify the source of the intracellular Ca 2؉ by using different inhibitors of calcium fluxes suggest that calcium enters from the culture medium through voltage-sensitive calcium channels.

Poliovirus infection induces apoptosis in CaCo-2 cells

“…Poliovirus-induced apoptosis in CaCo-2 cells could be linked to the activation of several mechanisms such as the modulation of intracellular calcium concentration. It has been reported previously that intracellular calcium concentration greatly increases during the course of poliovirus infection [Irurzun et al, 1995]. Thus, virus cytopathic effect could be mediated by an increase in intracellular Ca ++ induced by the synthesis of a viral product, the 2BC protein.…”

Viral calciomics: Interplays between Ca2+ and virus

“…The single-stranded, plus-sense RNA genome encodes 4 structural proteins (VP1-4) and 10 nonstructural proteins (2A pro , 2B, 2C, 3A, 3B, 3C pro , 3D pol , 2BC, 3AB, and 3CD pro ) that are produced by a proteolytic processing cascade from a single translational precursor. Among these, the 2BC polypeptide of poliovirus has been shown to induce an increase of [Ca 2+ ] CYT at 2-4 hpi [75,76]. This time point is coincident with a period during which the viral proteins are actively synthesized.…”

Cellular origin and ultrastructure of membranes induced during poliovirus infection

“…Cellular translation (30), transcription (17)(18)(19), and protein secretion (25) are inhibited. During the course of poliovirus infection, intracellular calcium concentrations increase greatly (44) and lysosomal enzymes redistribute into the cytosol (39). Starting at approximately 2 h postinfection, membranous structures begin to accumulate in the cytoplasm of poliovirus-infected cells; these structures were described 30 years ago by Dales et al as small, membrane-enclosed bodies (21) that range from 50 to 400 nm in size (16).…”