Persistence of coxsackievirus B4 infection in rhabdomyosarcoma cells for 30 months. Brief report.

A persistent infection of rhabdomyosarcoma (RD) cells by Coxsackie B4 virus (CBV-4) was established. The persistently infected RD (piRD) cells have been maintained for over 130 passages (30 months) and have released virus continuously without cellular destruction. The production of infectious virus declined three times during the study. After the first decline (third week post infection) a viral variant with a littered cytopathic effect (CPE) and a marked delayed replication cycle on Green Monkey Kidney (GMK) cells, replaced the original viral population. 100-fold diluted cell cultures were recovered from the piRD cells at the 48(th) and 104(th) passage. All 96 cultures from the former whereas 72% from the second dilution showed virus production when tested on GMK cells. Using a streptavidin/biotin immune-staining assay all piRD cells were positively stained. Test for ts mutants showed that the persistence of the CBV-4 strain was not dependent upon incubation temperature and addition of the antiviral compound disoxaril did not cure the piRD cells.