Heterotypic exclusion between vesicular stomatitis viruses of the New Jersey and Indiana serotypes

Co-infection of cells with vesicular stomatitis viruses of the Indiana and New Jersey serotypes results in interference. Using specifically-labelled immunofluorescent antibodies, it was demonstrated that within any one co-infected cell, one virus serotype replicated to the relative exclusion of the other serotype. This result was further substantiated by an examination of the virus serotypes released by infectious centres co-infected with both viruses. Dominance of one serotype over the other was shown to be a function of the relative multiplicity of the two viruses. Superinfection by the second serotype at a higher multiplicity resulted in dominance by the second virus during the early period (up to 1-5 h) post-infection. After this time, the minority virus was able to overcome this dominance. Dominance of the majority virus was also abolished by u.v; inactivation. Cell protein synthesis appeared to be less affected in cells infected with both serotypes than when infection was with a single serotype.