抄録
Synthesis of interferon (IF) was induced in chick embryo fibroblast (CE) cells by inoculations of Sindbis virus (SDV), and Newcastle disease virus (NDV) on SDV after irradiation of UV (UV-NDV or UV-SDV). However, CE cells infected with live NDV failed to produce IF. The IF production by these agents was found to be strongly inhibited by the superinfection of some live viruses. Following results were obtained.
1. The IF production in CE cells primed with SDV, UV-NDV and UV-SDV was suppressed by 1/8-1/64 fold by superinfection of NDV. Suppression of IF production was also observed in CE cells infected with doubly SDV and UV-NDV.
2. These inhibition were also observed in CE cells infected with UV-NDV or SDV by the superinfection with polio-virus and HVJ, but were not observed when influenza type A virus was employed as superinfecting virus.
3. The higher m. o. i. of superinfecting virus, the stronger the inhibition of the IF productions. However, the inhibition was not observed in CE cells inoculated doubly with UV-NDV, UV-SDV.
4. When superinfecting virus, NDV was introduced within 2 hours after inoculation of UV-NDV, IF synthesis was completely inhibited, however, the addition of NDV at 5 hours after the inoculation of UV-NDV was without effect.
5. The adsorption of UV-NDV to CE cells was not inhibited by the preinfection of SDV, and the synthesis of SDV was enhanced by the addition of UV-NDV to CE cells.
