IFN-β or poly IC treatment restricted the progression of Timer-CVB3 infection in HeLa cells at low multiplicities of infection.

<p><i>(A)</i> HeLa cells treated with IFN-β or Poly IC showed fewer signs of cytopathic effects and fewer green cells by fluorescence microscopy following infection with Timer-CVB3 as compared to untreated cultures at 24 hours PI. For HeLa cells given a relatively low amount of viral inoculum (moi = 0.01), untreated cultures showed the highest percentage of green cells. By 32 hours PI, the number of cells exhibiting cytopathic effects was similar across the three conditions, and the percentage of cells expressing green “fluorescent timer” protein was similar between the untreated and the poly IC-treated cultures. In contrast IFN- β -treated HeLa cells continued to show reduced numbers of green cells. By 48 hours PI, the majority of the infected HeLa cells expressed both early and late viral proteins (yellow signal), and no significant differences were observed between the three conditions. <i>(B)</i> The effects of IFN- β and poly IC were minimized at higher moi. <i>(C)</i>, <i>(D)</i> Viral titers were similar between treatments at both the low and high moi.