[Formation of transfecting DNA in acute cellular infection with the tick-borne encephalitis virus mediated by an oncogenic virus].

To prove the association of the transfecting activity of nucleic acid from cells co-infected with TBE and SV40 viruses with DNA, experiments were carried out using fractionation of nucleic acid preparations in cesium sulphate gradient an on a column with HAP. The experiments led to a conclusion that the infectivity of the preparations used was associated with double-stranded DNA. Investigation of nucleic acid infectivity form cytochalasine-enucleated cells indicated that the function of the nucleus was necessary for formation of transfecting DNA in mixed TBE and SV40 infection of cell. No formation of transfecting DNA was observed in experiments of blocking replication and transcription of cellular genome. The retention of the transfecting activity of DNA during 6 passages of cells at approximately the same level indicated the lack of selective preferences or inhibition of cells containing transfecting DNA.