Figure 3

HFRS-causing hantaviruses do not have the same capability as TULV to inhibit ERK1/2 activity. To assess the ability of hantaviruses other than TULV to inhibit ERK1/2, Vero E6 cells were mock-infected with fresh cell culture medium or infected with TULV, PUUV, TOPV and SEOV at a multiplicity of infection of 0.01 for 14 and 25 days. Cell lysates (50 μg protein) were immunoblotted for detection of phosphorylated ERK1/2 (p-ERK1/2) or total ERK1/2 (A). Bands were subjected to intensity analysis (ImageJ software; http://rsb.info.nih.gov/ij) and the amount of p-ERK1/2 related to mock sample at 14 and 25 days post infection. To investigate the correlation between ERK1/2 inhibition and the amount viral replication, virus titers were determined as focus forming units (FFU) from conditioned media of cell cultures and plotted together with fold inhibition of ERK1/2 activity in respective cells (B). Error bars for virus-titer measurements represent standard deviation. p.i. post infection.