MAVS and infection: To determine whether RSV NS2 is involved in NS1-MAVS interaction, A549 cells were infected with rA2 or rA2ΔNS2 (0.1MOI) and at 12 h post-infection (p.i.), cells were stained with the mitochondrial stain CMXRos (red), Alexa 488-conjugated anti-His6-NS1(green), and Alexa 647-conjugated anti-MAVS antibody (purple)and visualized using the Leica TCS SP2 laser scanning confocal microscope(Fig. 4A & B).Merged images of NS1with mitochondria and NS1 with MAVS are shown in figure 4A.