Hepatitis delta virus (HDV) and woodchuck hepatitis virus (WHV) nucleic acids in tissues of HDV-infected chronic WHV carrier woodchucks

Abstract

The molecular forms of genomic and antigenomic hepatitis delta virus (HDV) RNA and of woodchuck hepatitis virus (WHV) DNA and WHV RNA were studied in nonneoplastic liver (NL) tissues, hepatocellular carcinoma (HCC) tissues, and several extrahepatic tissues of chronic WHV carrier woodchucks acutely (two animals) and chronically (six animals) superinfected with HDV. HDV was shown to replicate in all NL and HCC tissues but not in any of the extrahepatic tissues analyzed, which included spleen, peripheral blood lymphocytes, kidney, ovary, testis, thymus, lung, and stomach. HDV RNA was present as species with molecular weights consistent with those of monomers, dimers, and trimers of both strand polarities, supporting the rolling circle model proposed for HDV RNA replication. WHV DNA levels in NL, HCC, spleens, and serum were 10- to 100-fold lower than the levels typically observed in chronic WHV carrier woodchucks not infected with HDV. WHV DNA replicative intermediates were rarely observed and only at very low levels, representing less than 10% of the total WHV DNA. By contrast, WHV RNA transcription was not significantly depressed and both primary WHV RNA transcripts, 2.3 and 3.6 kilobases, were observed in NL, HCC, spleens, and in one of the kidney tissues. In addition, a 2.6-kilobase WHV RNA transcript was found in the majority of the NL tissues.