DIFFERENTIAL PATTERN OF SEQUENCE HETEROGENEITY IN THE HEPATITIS-C VIRUS E1 AND E2 NS1 PROTEINS/

The E1 and E2/NS1 genes, encoding the putative hepatitis C virus envel ope proteins, show a high rate of sequence variations. We analyzed the degree and distribution of sequence heterogeneity in serum samples fr om hepatitis C virus-infected subjects. The mutations in the E1 region were mainly type-specific and the rate of variability was apparently not linked to the clinical phase of the infection. The sequence evolut ion of the E1 region during interferon treatment was low, regardless o f the response to therapy. In contrast, an increased degree of variati on, apparently related to the stage of viral replication, was present in E2 region derived from patients undergoing interferon treatment. Th ese results are consistent with the hypothesis that the E2 protein rep resents a major target of the immune response. (C) Journal of Hepatolo gy.