Cells Persistently Infected with Newcastle Disease Virus

Abstract

A comparison of the replication patterns in L cells and in chick embryo (CE) cell cultures was carried out with the Herts strain of Newcastle disease virus (NDVO) and with a mutant (NDVpi) isolated from persistently infected L cells. A significant amount of virus progeny, 11 plaque-forming units (PFU)/cell, was synthesized in L cells infected with NDV0, but the infectivity remained cell-associated and disappeared without being detectable in the medium. In contrast, in L cells