Formation and characterization of an intertypic lymphocytic choriomeningitis recombinant virus

An intertypic reassortant arenavirus has been obtained from co-infection of BHK-21 cells by two strains of lymphocytic choriomeningitis virus (LCM virus), WE and Armstrong (ARM), having the large/small (L/S) viral RNA genotype of WE/ARM. The two parental viruses have different virulence characteristics in hamsters and guniea-pigs. The reassortant virus induces LCM-WE-type plaques in Vero cell monolayers, but has the avirulent characteristics of LCM-ARM in hamsters and two strains of guniea-pigs. These results suggest that the LCM plaque phenotype is determined by L RNA gene products, while the pathogenic potential in guinea-pigs may be determined by S RNA gene products.