Strategies for Evaluation of Antiviral Agents Against Epstein-Barr Virus in Culture

Evaluation of antiviral agents against Epstein-Barr virus (EBV) has been hampered by the lack of a permissive cell system for the replication of this virus. The extent of EBV replication detected in producer cell lines (P3HR-1 and B95-8) is limited: only a small fraction (<10%) of the cell population spontaneously produces virus at any given time. Attempts to increase the virus yield by manipulation of the culture conditions, such as temperature shifts, exposure to halogenated pyrimidines, such as BUdR and IUdR, and X-ray, have not been very successful. Superinfection of Raji (a nonvirus-producer line) cells with P3HR-1 virus enhances EBV replication and provides a more efficient system for evaluation of antiviral drugs. However, this method requires infection with virus isolated from a large quantity of culture fluids of P3HR-1 cells The virus yield varies from preparation to preparation. In addition, the system is not practical for large-scale drug screening.