In this study, we tested whether treatment of CKII inhibitor could reduce virus production of genotype 1a HCV as efficiently as genotype 2a virus. Although many significant findings were made possible due to the development of genotype 2a JFH1 infectious clone, direct application of such findings in clinical trials should await further validation especially in genotype 1a cell 4431-01-0 culture system considering the aforementioned significant differences among the HCV genotypes. The effect of DMAT on the abundance of NS3 of H77S.3/4SA mutant was specifically surprising since such a substantial increase has never been found in any other mutant constructs. We tested ectopic expression of NS3 in the presence of DMAT by transfecting NS3 and NS3/4A expression plasmids. However, the abundance of NS3 protein decreased when the concentration of DMAT increased, thus excluding any stabilizing effect of NS3 protein in the presence of DMAT. This result is very MCE Company KJ Pyr 9 opposite to our previous data obtained with DMAT chemical inhibitor. However, the titer of JFH1 virus decreased whether the cells are either treated with DMAT or transfected by siRNA for CKII. The discrepancy between genetic inhibition and chemical inhibition data with H77S.3 virus suggests that the enhancement of H77S virus production in the presence of DMAT could be due to nonspecific target effect of this inhibitor and that this nonspecific effect is exclusive with this genotype 1a virus. We do not know which viral factor was affected nonspecifically by DMAT. Certainly, NS2 and NS5A domain III are not the targets of this effect since the two viruses which contain the same NS2 and NS5A domain III showed the opposite outcome upon DMAT treatment. Whatever is responsible for such nonspecific target effect, it seems to be strong enough to negate a small negative effect on H77S virus production by specific CKII inhibition. Since the nonspecific target effect of DMAT that we observed might be unique with this compound, we tried another CKII inhibitor, -3- acrylic acid. Both DMAT and TBCA are compounds derived from TBB, but TBCA has a better selectivity for CKII. Huh7.5 cells were transfected by HCV RNA and 6 hours after transfection, TBCA was added to the culture medium and maintained for 48 hours. Three days after transfection, culture supernatants were collected for virus titration. Although even higher concentration of TBCA was required to observe the effect on virus production, very similar results were obtained compared to those of DMAT. H77S.3 virus titer increased but JFH1 virus titer decreased when the concentration of TBCA increased. Most of the currently tested antivirals against HCV infection are targeted to viral proteins, specifically NS3 protease, NS5A, and NS5B. However, there are othe