Viral superinfection in cells carrying an arenavirus and/or a togavirus.

Four lines of the same L-cell clone were transferred 60 times in parallel: uninfected cells, a line carrying lymphocytic choriomeningitis virus (LCMV), another one carrying tick-borne encephalitis virus (TEV) and one carrying both viruses. In double persistency, LCM and TEV were suppressed and stimulated, respectively. Cell multiplication rates were comparable in all four lines. Single LCMV persistence caused marked resistance of L cells to superinfecting viruses from various taxonomic groups, but this phenomenon was abolished or even reversed to increased sensitivity in the cell line with co-persisting LCMV plus TEV.