Production of Hemagglutinin by Dengue Virus in HeLa Cells

Abstract
Summary Production of hemagglutinin by dengue virus types 1, 2, 3 and 4 has been demonstrated in the fluid phase of HeLa cells infected either with unadapted mouse brain virus or with high passage level HeLa cell adapted virus. Cell cultures inoculated with high passage levels of HeLa cell adapted virus of all 4 types showed the presence of hemagglutinin in infected fluids at the time of the first appearance of the cytopathic effect. High titers of hemagglutinin correlated with high TCD50 titers. Adaptation to in vitro conditions favored the production of hemagglutinin in cell cultures inoculated with dengue types 1, 3 and 4. Under the experimental conditions, type 2 unadapted mouse brain virus yielded higher concentrations of hemagglutinin than did type 2 high passage level HeLa cell adapted virus.