TABLE 5.

Susceptibilities of HCV NS3 protease variants to other anti-HCV agents in replicon cells^a

Variant	IFN-α		Ribavirin
	EC50 (U/ml)	Fold change	EC50 (μM)	Fold change
Wild type	11.6 ± 1.1	1.0 ± 0.1	58 ± 18	1.0 ± 0.3
V36M	11.3 ± 5.9	1.0 ± 0.5	33 ± 18	0.6 ± 0.3
V36A	10.3 ± 6.0	0.9 ± 0.5	43 ± 21	0.8 ± 0.4
T54A	3.9 ± 0.5	0.3 ± 0.04	22 ± 11	0.4 ± 0.2
V36M + R155K	10.1 ± 5.9	0.9 ± 0.5	41 ± 6	0.7 ± 0.1
V36A + R155K	6.8 ± 0.5	0.6 ± 0.04	36 ± 2	0.6 ± 0.04
V36M + R155T	3.1 ± 0.2	0.3 ± 0.02	36 ± 1	0.6 ± 0.02
V36A + R155T	3.9 ± 2.1	0.3 ± 0.2	42 ± 22	0.7 ± 0.4

^aStable cell lines containing wild-type and variant HCV subgenomic replicons were generated by using the T7 RNA runoff transcripts from the corresponding high-efficiency Con1 replicon plasmids. The average replicon EC₅₀ values of IFN-α and ribavirin ± SDs were determined for the HCV replicon cell lines in the 48-h assay in three independent experiments. The fold change was determined by dividing the replicon EC₅₀ of a given variant by that of the wild-type HCV replicon.