Selective resistance to togaviral superinfection in mice with tolerant lymphocytic choriomeningitis virus infection.

Mice infected neonatally with lymphocytic choriomeningitis virus (LCMV) developed partial and complete resitance to cerebral superinfection with tick-borne encephalitis virus (TEV) in 10 and 20 days after birth, respectively. This resistance lasted at least till the age of 40 days. LCMV tolerant mice neither succumbed to TEV infection, nor circulated TEV in their blood. Moderate, gradually decreasing TEV titres were detected in the brains and TEV-induced brain interferon was lower than in control mice of the same age. TEV superinfection caused a significant depression of the blood titre of tolerated LCMV while the titres in the brains remained equal to those in tolerant but not superinfected mice. LCMV tolerant mice showed a similar resistance to another togavirus (chikungunya) but not to encephalitogenic picorna-, herpes- and rhabdoviruses.