Transfer of interferon-producing macrophages: new approach to viral chemotherapy.

Mice were protected from infection with Semliki Forest virus and encephalomyocarditis virus by the transfer of peritoneal macrophages that were stimulated to produce interferon in vitro by exposure to a nonreplicating virus. This method of therapy was also utilized in animals infected with encephalomy-ocarditis virus after onset of clinical signs. Of these animals 40 percent recovered, but only 9 percent of the control group recovered.