FIGURE 5.

The addition of adenine attenuates the inhibitory effect of SMeFM on viral propagation. (A) Inhibition of plaque formation by SMeFM. MDCK cells were infected with the influenza A virus (WSN strain, 20 PFU) and were overlayed with MEM-0.8% agarose containing SMeFM or T-705. After 48 h incubation, the cells were fixed and stained by amido black. (B) Plaque assay with SMeFM and nucleobases. MDCK cells were infected with the influenza A virus (20 PFU) and were overlayed with MEM-0.8% agarose containing 3 μM SMeFM and an indicated nucleobase (20 μM). (C) The plaque size with SMeFM and adenine. The plaque of infected cells overlayed with agarose containing DMSO, both DMSO and 20 μM adenine, 1 μM SMeFM, or both SMeFM and adenine (left panel). The plaque size incubated with DMSO, both DMSO and adenine, SMeFM, or both SMeFM and adenine (n = 30, 30, 18, and 32, respectively) was measured and plotted (right panel). P-values were calculated by Wilcoxon rank sum test and were corrected by Bonferroni method.