Chronic infection of HeLa cells with Japanese encephalitis virus. General characteristics of the system.

Chronic infection of HeLa cells was induced by an attenuated variant of Japanese encephalitis (JE) virus (HeLa-K3 cell line). The chronic infection was characterized by alternating phases of degeneration and recovery of the cell monolayer. JE virus was regularly released into the medium of chronically infected cell cultures and virus-specific antigen was regularly demonstrated in the cytoplasm of 15--25% of cells. JE virus persisting in HeLa-K3 cells was sensitive to pancreatic ribonuclease and resistant to treatment with 4 M urea. HeLa-K3 cells did not undergo cytological or karyological transformation; they were susceptible to superinfection with heterologous viruses but resistant to reinfection with homologous virus.