Selection and characterization of virus-resistant L cell mutants with changed interferon gene expression

A study was carried out on the relationship between the antiviral behaviour and changes in interferon (IFN) gene expression of virus-resistant cell mutants. Three virus-resistant L cell mutants were selected by mutagen-selection method. These mutant cell lines were found to show marked changes in their behaviour in both IFN induction and IFN action systems. An accelerated IFN induction response was observed in mutant cell cultures when they were exposed to NDV. Induced mutant cells synthesized IFN mRNA more quickly, and the IFN titers after induction with poly I:C were higher in mutant cell lines than those in the parent cell line. The virus-resistant L cell mutants appeared to be more sensitive to the anticell-division activity caused by ppp A2'p5'A2'p5'A. The results obtained suggest that changes in IFN gene expression may account for the antiviral behaviour of these cell mutants.