title: Sequence analysis of hepatitis B virus DNA in immunologically negative infection.
abstract: It was previously demonstrated that the serum of some patients without immunological evidence of HBV infection contains the virus. Here we demonstrated by sequence analysis that the serum of such a patient contained a mixed HBV population. In comparison with HBV genomes of different genotypes twenty-two nucleotide variations were found in all clones sequenced in parallel. One nucleotide variation was identified within the enhancer I. Twelve of the twenty-two nucleotide variations caused altogether fifteen changes of amino acid sequence in known or predicted viral proteins. The proteins of the P open reading frame, which are most important for viral replication, were affected by nine amino acid substitutions. Three amino acid substitutions concerned the product of the X gene, a transcriptional transactivator of various viral and cellular promoters. Three mutations were only observed in some of the clones. One point mutation affected the direct repeats of the enhancer II. It occurred together with an 8 bp-deletion involving the C promoter region and the X gene. The third mutation was a single insertion, causing a fusion of the X and C gene. One or several of the identified mutations could be responsible for the diminished rate of replication and consequently for the low-titred, immunologically negative HBV infection.
authors.affiliation: Abteilung für Hepatologie und Gastroenterologie, Albert-Ludwig-Universität, Freiburg, Federal Republic of Germany.
authors.forename: S
authors.initials: S
authors.lastname: Preisler-Adams
authors.forename: H J
authors.initials: HJ
authors.lastname: Schlayer
authors.forename: T
authors.initials: T
authors.lastname: Peters
authors.forename: F
authors.initials: F
authors.lastname: Hettler
authors.forename: W
authors.initials: W
authors.lastname: Gerok
authors.forename: J
authors.initials: J
authors.lastname: Rasenack
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000737:chemistry; D004279:DNA, Viral / Q000737:chemistry* / Q000302:isolation & purification; D014644:Genetic Variation; D016679:Genome, Viral; D006509:Hepatitis B / Q000276:immunology / Q000382:microbiology*; D006511:Hepatitis B Antigens / Q000235:genetics; D006512:Hepatitis B Core Antigens / Q000235:genetics; D006514:Hepatitis B Surface Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D015534:Trans-Activators / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics; D054334:Viral Regulatory and Accessory Proteins; D014779:Virus Replication / Q000235:genetics
chemical_list: D017931:DNA Primers; D004279:DNA, Viral; D006511:Hepatitis B Antigens; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D015534:Trans-Activators; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C057628:hepatitis B virus X protein