LGTV replicated well in both cell lines, but the titer was 2-3 logs lower in acutely infected ISE6 cells than in Vero cells (Fig. 1B) . Thus, there was a prominent difference in the cellular response to acute LGTV infection between mammalian and tick cells. For subsequent experiments, we selected a time point of 48 hpi as a compromise between virus production and integrity of cellular morphology.