The Vacuolating Virus of Monkeys

Abstract

The vacuolating virus SV40 has been recognized as an entity for a relatively short time. Sweet and Hilleman (17, 18) summarized some of the characteristics of the virus but there has been available no information regarding its morphology or intracellular distribution. More recent observations (9) have shown that cells infected with the vacuolafing virus often display well marked, intranuclear, inclusion bodies. The inclusions usually appear in advance of cytoplasmic vacuoles and, as a consequence, it seemed probable that the origin of the virus was in the nuclei of infected cells. For that reason, the following observations were directed toward a study of the nuclear events following infection and, more specifically, toward a description of the virus particle and its intracellular distribution. Materials and MethodsVirus.--Two strains of vacuolating virus (SV,0) were studied. One, PA-57, was isolated by one of us from a patas monkey (Erythrocebus paras) kidney culture in 1957 and carried since that time in paras cultures. Two lines of this strain (including two passage levels of one line) were examined.Strain "CA 45-54 (Sweet and Hilleman), obtained through the courtesy of Dr. Hilleman, was received as the first subculture in grivet monkey (Cemopithecus aettdops) kidney cultures.It was carried in paras cultures in this laboratory.Cells.--Cultures of paras monkey kidney and human kidney were prepared as described previously (10). All cells were seeded on coversllps in Leighton tubes.Fixation and Staining.---Cells prepared for light microscope studies were stained as routine with hematoxylin and eosin after fixation in Zenker's solution, as described in the preceding paper. For special purposes, however, preparations were stained with hematoxylin and ensin after fixation in 10 per cent buffered formalin, Camoy's solution, or after Camoy's fixation followed by hydrolysis in hydrochloric acid, as for the Feulgen reaction. The Fenlgen reaction was performed on cells after fixation in Carnoy's solution for varying periods of time, from several minutes to several days, without noticeable differences.

Electron Microscopy

“…The common use of cultures of monkey tissues as in vitro hosts for viruses in research and vaccine production lent emphasis to studies of simian viruses. (155) first reported the morphology and intranuclear replication site of the simian vacuolating agent SV 40. Subsequently Mayor and co-workers have used electron microscopy in biophysical studies (291) of the virus particle and cytological studies (293) of its growth cycle in monkey kidney cell cultures.…”

Studies on the Multiplication of Simian Virus 40 (Vacuolating Virus) by Means of Fluorescent Antibody Technique

“…In parallel with the fluorescent antibody staining each cell monolayer on a coverslip was fixed in Zenker's fluid followed by hematoxylin-eosin staining in the same manner as described by Gaylord et al (1961).…”