The Growth of Rabbitpox Virus in Tissue Culture

Abstract

The growth of rabbitpox virus has been studied in monolayer cultures of HeLa (ERK) cells. At 36[degree], virus was adsorbed to cells at about one-tenth of the theoretical collision rate. The adsorbed virus penetrated the cells exponentially, the time for half penetration being about 1 hr. New infective virus began to appear at 5 hr, and the final yield at 24 hr was about 100 pfu per cell. The synthesis of viral antigen began 1 1/2 hr after infection of the cultures; this was 1 hr before the earliest appearance of viral DNA. When virus growth was complete, over 20 separate antigens could sometimes be detected in extracts of infected cells. The yield of antigens was not reduced when virus multiplication was completely inhibited by bromodeoxyuridine. It was concluded that the synthesis of viral antigens was directed by the DNA of the infecting virus, and not by the DNA formed during virus growth.