DETECTION OF THE PUTATIVE-E2 PROTEIN OF HEPATITIS-C VIRUS IN HUMAN LIVER

The question was asked whether a predicted envelope protein, considere d to be processed from the polyprotein precursor encoded by the putati ve E2/NS1 region of the hepatitis C virus (HCV) genome, may be observe d in HCV-infected humans. Two polyclonal antibodies against recombinan t E2/NS1 proteins were prepared and their reactivity tested against li ver extracts from HCV-infected patients by immunoblotting analysis. A band corresponding to a size of 44 kDa was detected in liver extracts from patients who were positive for the HCV-specific antibody anti-C10 0-3 but not in liver extracts from patients who did not have anti-C100 -3 antibody. Additionally, no band was detected using preimmune sera o r antisera which had been preabsorbed with recombinant E2/NS1 proteins . Deglycosylation studies demonstrated that the 44 kDa protein was a g lycosylated form of a 38 kDa protein which corresponds to the predicte d molecular weight of the putative E2/NS1 protein. These results sugge st that the 44 kDa protein is a product of the E2/NS1 region. Frequent observation of the 44 kDa band in cases of chronic active hepatitis C suggests a correlation between the expression of this protein and the progression of hepatitiS. (C) 1994 Wiley-Liss, Inc.