Interferon inducibility in mice treated with Corynebacterium parvum.

Mice were given single intraperitoneal (i.p.) injections of Corynebacterium parvum, followed, after different time intervals, by i.p. injections of the interferon inducers polyinosinic-polycytidylic acid (poly-I:poly-C), 10-carboxymethyl-9-acridanone (CMA) or herpes simplex virus. With all three inducers production of interferon in the peritoneal cavity was enhanced in C. parvum-pretreated mice. Production of circulating interferon in C. parvum-pretreated mice was enhanced with CMA and depressed with poly-I:poly-C as inducers. This modulation of the interferon response was prominent for at least 10 weeks after C. parvum injection and then gradually reverted. The increased local interferon production seemed to be caused by macrophages still activated several weeks after treatment with C. parvum.