RT Journal Article SR Electronic(1) A1 Mirchamsy, H. A1 Rapp, F.YR 1969 T1 Role of Interferon in Replication of Virulent and Attenuated Strains of Measles Virus JF Journal of General Virology, VO 4 IS 4 SP 513 OP 522 DO https://doi.org/10.1099/0022-1317-4-4-513 PB Microbiology Society, SN 1465-2099, AB Summary Small concentrations of actinomycin D increased the yields of both virulent and attenuated strains of measles virus in cultures of the stable simian BSC-1 cell line by as much as five- to tenfold. The edmonston virulent strain of measles virus did not induce detectable levels of interferon in these cells but interferon was induced by the schwarz vaccine (attenuated) strain of virus over a wide range of virus input. Actinomycin D suppressed the induction of interferon in BSC-1 cells. Interferon produced in BSC-1 cells by the attenuated virus was able to protect both these cells and Vero (another stable line of green monkey kidney) cells against vesicular stomatitis virus. Plaques produced by the virulent and attenuated virus in Vero cells were approximately the same size, in contrast to variations observed in BSC-1 cells. This was correlated with the failure of the Vero cells to produce interferon when inoculated with either the virulent or attenuated strain of virus and the failure of actinomycin D to affect yields of infectious virus. The results suggest that the effect of actinomycin D on virus yields and on plaque size in BSC-1 cells is a result of inhibition of induction of interferon., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-4-4-513