Induction of cytokines by tilorone hydrochloride.

Tilorone hydrochloride, an interferon inducer in small laboratory animals, was demonstrated to elicit formation of macrophage migration affecting and microbial growth inhibitory cytokines after peroral drug administration to mice. Serum kinetics of the migration inhibitory cytokine resembled those of interferon, exhibiting a peak after about 24 h, whereas the bactericidal cytokine showed a steady increase up to 48 h after drug treatment. Both the factors were found to have molecular weights of 10,000--30,000 daltons as determined by Sephadex G-200 chromatography, to be stable at pH 2 and at 56 degrees C for 30 min, sensitive to chymotrypsin and resistant to RNase digestion. The migration enhancing serum activity could not finally be characterized so far. The physicochemical data are discussed in comparison to those of lymphocyte-derived cytokines. It is suggested that cytokine production may be, at least partially, responsible for the immunological effects of tilorone and possibly contribute to its antiviral action.