Acceleration of Scrapie in Mice by Target-organ Treatment with Interferon Inducers

Interferon inducers were used in the target-organ treatment of scrapie in mice. Intracerebral treatments began 24 hr prior to intracerebral inoculation of 10(4.8) LD50 of the Chandler strain of scrapie agent. The treatments included 30 and 0.3 microgram poly(I:C) given weekly 9 times, 45 microgram statolon given biweekly 7 times, or 1.5 HA units of Sendai virus given biweekly 6 times. All treatments except the lower dose of poly(I:C) accelerated death in scrapie-affected mice. Compared to saline-treated control groups, 30 microgram poly(I:C), given weekly, shortened the mean survival time 13.5 days. Groups treated with statolon or Sendai virus had their mean survival times shortened 18.5 and 21.7 days, respectively. Infected mice were also evaluated for signs of disease at approximately weekly intervals using a numerical scoring method. Acceleration was also apparent using this parameter of disease. When treatment occurred only once, Sendai virus was the only inducer to significantly shorten the survival of mice.