Replication dynamics of tick-borne encephalitis virus in, and glycolytic activity of, human diploid cells.

Tick-borne encephalitis (TBE) virus (Western subtype) strains replicated very rapidly in human diploid embryonic lung (HDEL) cells, namely within the first 24 hours of infection. Greater amounts of both intra- and extracellular virus were produced after inoculation of a virulent than of an attenuated strain. With the virulent strain, more infectious virus was found in the medium than in the cells: the opposite was true for the attenuated strain. No cytopathic effect was observed during the period studied. The rates of glucose uptake and lactate production by cells were markedly influenced by the infection. Lactate production was retarded by both virus strains to a comparable degree. Glucose uptake was markedly increased, appreciably more so after infection by the virulent than the attenuated strain. A method for differentiating between attenuated and virulent strains based on the determination of glucose conthe medium was developed.