Abstract
The defective adenovirus-associated viruses produce infectious progeny only in cells co-infected with an unrelated helper adenovirus. However, the adenovirus-associated viruses produce antigen detectable by immunofluorescence but not infectious virus in cells co-infected with herpes simplex virus. This incomplete helper effect provided by herpes simplex virus was studied in Hep-2 cells by quantitative kinetic procedures. Dose response studies showed that a single infectious adenovirus associated virus-1 particle and a single infectious herpes simplex virus particle were sufficient to initiate adenovirus-associated virus antigen synthesis. Adenovirus-associated virus-1 antigen was formed 6 hr after infection with both viruses, and at a time before the production of infectious herpes simplex virus. Co-infected cells, deprived of arginine, formed adenovirus-associated virus-1 antigen while undergoing an abortive herpes simplex virus infection in which infectious herpes simplex virus was not produced.
Sequential inoculation studies showed that the 6 hr latent period for adenovirus-associated virus antigen formation was lengthened, rather than shortened, by pre-infection with herpes simplex virus. Cytosine arabinoside treatment of co-infected cells within 4 to 6 hr after infection prevented adenovirus-associated virus antigen formation.