Genetic reassortants of lymphocytic choriomeningitis virus: unexpected disease and mechanism of pathogenesis.

Reassortant viruses of different strains of lymphocytic choriomeningitis viruses cause lethal disease after inoculation into neonatal BALB/c WEHI mice, but, in contrast, parental strains or reciprocal reassortants do not cause lethal disease. The disease is characterized by inhibition of growth and death. The pathogenic mechanism is the induction of interferon combined with higher virus titers and subsequent liver necrosis. The generation of lethal reassortants from nonlethal parent viruses likely has implications for understanding the outbreaks of unanticipated virulent disease within a viral family.