The Relationship Between Cytotoxicity and Interferon Induction in L-M Strain Mouse Fibroblasts

Summary

The incidence of cell damage in L-M cell cultures exposed to DEAE-dextran increased with an increase in the concentration of the polycation. Poly I:C alone exerted a toxic effect which could be neutralized by 10 μg DEAE-dextran/ml. Cytotoxicity, however, was potentiated by poly I:C at higher DEAE-dextran concentrations. The plaque reducing activity of the supernates from cultures exposed to poly I:C and DEAE-dextran increased with an increase in the incidence of cell damage. The antiviral substance, when induced by 10 μg/ml poly I:C and 400 μg/ml DEAE-dextran, was evident after an exposure of one hour. The potency of the material increased with the duration of exposure. The material was characterized as an interferon by its pH stability and trypsin sensitivity.

The authors acknowledge the excellent technical assistance of Mrs. Patrica Thomson. This work was supported by U.S. Public Health Service Grant GM-T-505 and a Biomedical Science Support Grant from Rutgers University.