抄録
Cytopathic effect in Vero cultures caused by the two representative laboratory strains of rubella virus was investigated from the point of view whether the CPE is virus specific or not. Serologically, the CPE was neutralized by rubella convalescent patients' sera to high titers whereas no neutralization was observed by various kinds of heterologous virus antisera. Rabbit immune sera prepared in this laboratory against the Vero-grown rubella viruses did not neutralize heterologous viruses covering various groups except HVJ against which the preimmunization rabbit sera were found to be neutralizing, too. Hemagglutinin against goose erythrocytes was produced in the infected Vero cultures. Using this hemagglutinin hemagglutinin-inhibition tests were performed on the rubella patients' paired sera, anti-rubella virus sera obtained from other laboratories and the above-mentioned homologous and heterologous immune sera in parallel tests with BHK-21 produced hemagglutinin. Comparable results were obtained with both HA antigens, so that specificity of the hemagglutinin produced in Vero was acceptable.
Neither cytoplasmic nor intranuclear inclusion bodies were found in the hematoxylin-eosin stained preparations of infected Vero cells. No hemadsorption of guinea pig erythrocytes was observed in the infected cultures. No production of hemagglutinin for chicken red blood cells in allantoic fluid occurred after allantoic inoculation of embryonated chicken eggs with the Vero grown viruses. New born mice survived without showing any symptoms after intracerebral inoculation with the agent. Sensitivity to chloroform and RNA type of the agent as determined by IUDR inhibition test of virus growth were also proved. Filtration tests using Millipore membranes gave suggestive results of around 50mμ diameter of particle size of the CPE agents. Rapid inactivation by 1:4000 formalin at 37°C was demonstrated with the Vero grown viruses as tested in Vero cultures for residual infectivity.
These results do not contradict the reported properties of rubella virus and can exclude a wide range of heterologous viruses as the CPE-causing agent for Vero cells or as contaminating viruses in the virus stocks tested by us. If follows that the cell line, Vero, can be used as one of the suitable CPE system for rubella virus study.
