ANALYSIS OF THE CELL TROPISM OF HCV BY USING IN-VITRO HCV-INFECTED HUMAN-LYMPHOCYTES AND HEPATOCYTES

Background/Methods: We recently established two hepatitis C virus (HCV ) replication systems, using MT-2, a human T-cell leukemia virus type I-infected human T-cell line, and PH5CH, a non-neoplastic human hepato cyte line immortalized with simian virus 40 large T antigen, These HCV replication systems were used to assess the infective potencies of se ven sera containing more than 10(6) HCV genomes per mi obtained from H CV-positive blood donors, Results: The results showed that these sera had different infectivities for MT-2 and PH5CH cells, One of the seven sera, 1B-1, was more infective for MT-2 cells than PH5CH cells, where as all the sera except serum 1B-1 were more infective for PH5CH cells than for MT-2 cells, Intracellular HCV RNA could be detected at least 30 days after inoculation with three of the sera, These findings sugge sted that the infective potency of each serum depends on the type of t arget cells, To further investigate HCV replication in these cells, we examined the hypervariable region 1 (HVR1) populations of HCV recover ed from both MT-2 and PH5CH cells at 8 days postinoculation, The resul ts revealed that the shift to limited HVR1 populations from the quasi- species of HVR1 populations in both cells usually occurred within 8 da ys after virus inoculation, Furthermore, in two of four sera, the pred ominant HVR1 populations in MT-2 and PH5CH cells appeared to be differ ent, Conclusion: These results suggest that HCV exhibits cell tropism.