Brief Communication: Detection of Mason-Pfizer Virus Infection With Human KC Cells Carrying Rous Virus Genome2

Abstract

Human KC cells carrying the Rous sarcoma virus (RSV) genome formed massive syncytia when cocultivated with cells infected by the Mason-Pfizer monkey virus (M-PMV). Syncytia were also induced when a concentrated M-PMV preparation was added directly to the KC cells. Syncytia were not observed when 118 MG cells (parent KC cells free of RSV) or XC cells were cocultivated with M-PMV-infected cells. The KC test was as sensitive as viral polymerase or immunofluorescence tests for detection of M-PMV infections. Syncytia induced by cellfree M-PMV disappeared on serial passage of the KC culture, and a chronic M-PMV infection was established. This culture then lost its capacity to form syncytia when superinfected with M-PMV or cocultivated with M-PMV infected cells.