[Clone cells obtained from continuous cultures and differing in their sensitivity to tick-borne encephalitis viruses].

Studies on cloning of continuous HEp-2 and SPEV cell lines were carried out. The sensitivity of the resulting clones to tick-borne encephalitis virus was determined and the clone lines were shown to be heterologous in their sensitivity to TBE virus by means of the immunofluorescence and virological methods. Among 47 clones of HEp-2 line virus reproduction was observed in 30 clones, no reproduction was demonstrated in 17 clones. The maximum number of cells simultaneously synthesizing virus antigen did not exceed 35% of the population which was conformity with the results obtained in the study of the original HEp-2 cell line. Twenty-nine clones derived from the continuous SPEV cell line were examined. Reproduction of the virus was observed in all of them. However, according to the maximum number of cells involved in the process of antigen synthesis, all the clones could be divided into two groups which differed also by the dynamics of cell involvement in antigen synthesis. The results of the study of clones derived from chronically TBE-infected Hep-2-Soph cell line are presented. In 13 out of 15 clones, the infectious virus and antigen synthesis were demonstrated which suggested that the majority of cells of the parental HEp-2-Soph line had been infected with TBE virus.