Arenavirus-induced cytopathic effect in MDCK cells : A model for the persistent infection of the mouse

Abstract

Arenaviruses kill Madin-Oarby canine kidney (MOCK) cells as shown by cloning in the presence of neutralizing antibody. Three strains (USC, WCP, and Traub) of lymphocytic choriomeningitis virus (LCM), as well as Pichinde virus, exhibited this phenomenon. Although single hit kinetics were observed with LCM virus, the cell killing reached only a maximum of 80%. After exposure to defective interfering (DI) LCM virus, MOCK cells became refractory to the killing potential of standard LCM virus. This was a dose-dependent effect. The "modified" MOCK cells that survived the standard virus infection because of pretreatment with DI virus had the following properties: division at a normal rate, resistance to standard virus challenge as shown both by cloning efficiency and PFU yields, and possession of viral specific antigens as shown by fluorescent antibody staining. Thus, DI virus prevention of the cytolytic potential of arenaviruses may be a key factor in the establishment and maintenance of arenavirus persistent infections in vitro as well as in vivo.