FIG. 7.
siRNAs combined with cidofovir are strongly synergistic against VACV-WR replication in HEL cells. (A to C) Isobolograms showing the effect of a combination of cidofovir with either siB1R-2 (A), siG7L-1 (B), or siD5R-2 (C) against VACV-WR growth in HEL cells. The numbers on the axes represent normalized FIC values (see Materials and Methods). The diagonal line connecting the FICsiRNA of 1 on the ordinate axis with the FICcidofovir of 1 on the abscissa axis corresponds to the line of additivity (unity line). Experimental data points located below, on, and above the unity line indicate synergy, additivity, and antagonism, respectively. Combination measurements were done in three independent experiments, and the most representative data are shown.