[Comparative study of B-lymphocyte activity in the spleen of mice infected with viruses of the tick-borne encephalitis complex].

Most arbovirus infections are characterized by multiplication of the causative agent in tissues of the reticuloendothelial system. In this study, the effect of some viruses of the tick-borne encephalitis complex on the reaction of B-cells of mouse spleens was investigated by the hemolysin-producing activity (number of plaque-forming cells). To equal small doses of a highly virulent (Pan), naturally attenuated (Tp-21) and experimentally attenuated (Tp-21-237) strains the immunocompetent cells of mouse spleens responded by active reactions. The immunocompetence of these cells after primary introduction of the antigens persists and revaccination response occurs after a secondary infection with the same viruses. Under these experimental conditions the active response of spleen cells to the antigenic stimulation correlates with formation of the specific resistance and does not correlate with the level of antihemagglutinins in the blood.