Abstract
The nature of tubular structures (TS) specifically found in cells infected with herpes simplex virus type 2 (HSV-2) was investigated by studying the appearance of TS in mixed infections with herpes simplex virus type 1 (HSV-1) and HSV-2 in Vero cells. Mixed infections with HSV-1 and HSV-2 resulted in a notable reduction in TS appearance. Accumulation of TS in cells infected with u.v.-irradiated HSV-2 was decreased by superinfection with HSV-1. The majority of progeny viruses obtained from mixed infection with HSV-1 and HSV-2 was neutralized by type-specific anti-HSV-2 serum, but not by type-specific anti-HSV-1 serum. Analysis of the genotype of the progeny revealed that the yield from mixed infection contained both HSV-1 and HSV-2 genotypes. These observations indicate that the majority of HSV-1 progeny of mixed infection is phenotypically mixed and make it possible to propose that TS are materials related to the type-specific antigen for HSV-2 which can be utilized by superinfection with HSV-1, producing phenotypically HSV-2 particles.