Studies on the Etiology of Marek's Disease. I. Propagation of the Agent in Cell Culture

Summary

A focal cytopathic effect (CPE) was observed in duck embryo fibroblast (DEF) cultures 11-25 days postinoculation with blood from the JM strain of Marek's disease (MD). All cell suspensions from such cultures reproduced MD when inoculated into chicks, while all of the morphologically normal DEF cultures were noninfectious. The CPE and infectivity were maintained in DEF cultures for 182 days. Both the induction of CPE in cell cultures and MD in chickens required intact cells in the inoculum. These data indicate that the JM strain of MD was successfully propagated in DEF cultures and produced a characteristic CPE.