Replication of the Trichoplusia ni granulosis and nuclear polyhedrosis viruses in cell cultures.

Newly established Trichoplusia ni (cabbage looper) embryonic cell lines were infected with T. ni granulosis virus (TnGV) and T. ni nuclear polyhedrosis virus (TnSNPV). Infection of cultured cells with TnGV was ascertained by peroxidase-antiperoxidase staining, DNA slot-blot hybridization, and transmission electron microscopy. Initially, 15 cell lines supported TnGV replication, the percentage of infected cells ranging from 1 to 50%.However, susceptibility of the 15 cell lines to TnGV infection either decreased or was lost within 20 to 25 passages from the initial primary culture. Infection of cells with TnSNPV was determined by phase contrast and electron microscopy. TnSNPV infected 29 36 cell lines tested, the percentage of infected cells ranging from 1 to 60%.