Phase Contrast Cinematography of Cellular Lesion Produced by Poliomyelitis Virus in vitro

Abstract

A previous study of the characteristics of the lesion produced by poliomyelitis virus in vitro in fixed and stained preparations of human adult fibroblasts indicated that an msinophilic area, which becomes soon more precisely outlined, appeared in the perinuclear cytoplasm between 15 and 20 hours after infection( 1). As this eosinophilic mass increased in size in the center of the cell, the nucleus and the cytoplasm, which became increasingly basophilic in content were pushed to the periphery. A t the next stage, the cell progressively emptied itself of its cytoplasm. We have since observed a similar lesion in fixed and stained preparations of fibroblasts derived from human embryonic muscle and of human and monkey kidney epithelial cells, infected with poliomyelitis virus. The increasing basophilia of the virus-infwted cell was found to be associated with a strongly positive and generalized Gomori alkaline phosphatase reaction. The purpose of the present communication is to describe the evolution of the cellular lesion as it was observed by phase contrast cinematography wikhout fixation or staining.Materials and methods. Strains of fibroblasts derived from human ,tonsils were maintained by serial passage in roller tubes for 2 to 3 months before they were used. These cells are 3 to 4 times as large as the average skin-muscle fibroblasts, regular in shape, and remarkably resistant to nonspecific degeneration. Their susceptibility to poliomyelitis virus was reported in a previous communication (2 ) . For examination with the phase contrast microscope explants were prepared by the hanging drop technic. The medium consisted of chicken plasma, human serum free of antibodies for the viruses that were used, bovine amniotic fluid, Hanks' solution and traces of chick embryo extract. The MEFl strain of Type 2 virus and the Mahoney strain of Type 1 poliomyelitis virus were used and it may be noted that the lesions were the same with both. Before transplantation to the hanging drop the cells were mixed with virus suspensions having a titer of 1k5 and left at room temperature for 30 minutes. Observations were carried out at 36-37OC and at 30-31°C. The evolution of the lesion was slower at 30-31°C but otherwise the same at both temperatures. The lower temperature was used more often because the control cells remained in better condition at 30-31°C. The observations were recorded with a Zeiss; Winkel phase contrast microscope at magnifications of 240X, 540X and 9OOX, using a 1OOV tungsten, ribbon lamp for the light source. The moving picture system of the camera was the one designed by J.

Structure and Development of Viruses as Observed in the Electron Microscope

“…18, 19). A similar mechanism has been observed in vital preparations of ECHO virus (17) and poliovirus-infected tissue cultures (3). The foregoing modes of release appear to be variants of a basic mechanism, namely, a weakening of the plasma membrane with resultant discrete or extensive rupture of the cell and extrusion of varying amounts of cytoplasmic material including virus.…”

A Phase Cinematography Study on Morphological Changes of FL‐Line Cells Following the Infection of Poliovirus

“…Changes in the cytoplasm were found to take place in FL cells after the nucleus had undergone considerable distortion. In poliovirus-infected human fibroblastic cells, Barski et al [1] observed that a dense and motionless paranuclear mass appeared 20 hours after the inoculation of virus, whereas in the present study a paranuclear mass of a similar nature appeared as early as 8 hours after inoculation. It is probable that the different results presented in two different series of study may be eventually attributable to the difference in cell lines used for study.…”

Egress of non-enveloped enteric RNA viruses

“…Non-lytic release of poliovirus was first suggested in the 1950s when researchers observed 'bubbling' and vacuolation in infected fibroblasts from adult human tonsils [99].…”

“…Non-lytic release of poliovirus was first suggested in the 1950s when researchers observed ‘bubbling’ and vacuolation in infected fibroblasts from adult human tonsils [99]. A decade later, non-lytic poliovirus release by extracellular vesicles likely derived from the endoplasmic reticulum, the origin of autophagosome membranes, was shown [100].…”