title: TT virus-derived apoptosis-inducing protein induces apoptosis preferentially in hepatocellular carcinoma-derived cells.
abstract: TT virus (TTV) is widespread among the global population. Its pathogenic nature is still unclear but TTV seems to be more prevalent in cases of hepatitis than in healthy individuals. TTV harbours similarities to chicken anaemia virus (CAV). Here, the apoptotic potential of a putative TTV-derived 105 aa protein and of the main apoptosis-inducing agent of CAV, Apoptin, is compared. As the putative protein induced apoptosis in various human hepatocellular carcinoma (HCC) cell lines, it was named TTV-derived apoptosis-inducing protein (TAIP). The apoptotic activity of TAIP in HCC lines was comparable with that of Apoptin. Conversely, unlike Apoptin, TAIP induced only low-level apoptosis in several non-HCC human cancer cell lines. The data suggest that TAIP acts in a different way to Apoptin as it is selective to a certain degree for HCC lines. This activity of TAIP, coupled with the heterogeneity of TTV isolates, may help to explain the variable reports of TTV pathogenicity.
authors.affiliation: Leadd BV, Leiden, The Netherlands.
authors.forename: Klaas
authors.initials: K
authors.lastname: Kooistra
authors.affiliation: BFSC, Leiden Institute of Chemistry, Leiden University, PO Box 9503, 2300 RA Leiden, The Netherlands.|Leadd BV, Leiden, The Netherlands.
authors.forename: Ying-Hui
authors.initials: YH
authors.lastname: Zhang
authors.affiliation: Leadd BV, Leiden, The Netherlands.
authors.forename: Niek V
authors.initials: NV
authors.lastname: Henriquez
authors.affiliation: Research Laboratories of Schering AG, Berlin, Germany.
authors.forename: Bertram
authors.initials: B
authors.lastname: Weiss
authors.affiliation: Research Laboratories of Schering AG, Berlin, Germany.
authors.forename: Dominik
authors.initials: D
authors.lastname: Mumberg
authors.affiliation: BFSC, Leiden Institute of Chemistry, Leiden University, PO Box 9503, 2300 RA Leiden, The Netherlands.|Leadd BV, Leiden, The Netherlands.
authors.forename: Mathieu H M
authors.initials: MHM
authors.lastname: Noteborn
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D019556:COS Cells; D036022:Capsid Proteins / Q000502:physiology; D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D045744:Cell Line, Tumor; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology*; D008969:Molecular Sequence Data; D022783:Torque teno virus / Q000472:pathogenicity*; D014764:Viral Proteins / Q000502:physiology*
chemical_list: D036022:Capsid Proteins; C091717:VP3 protein, Chicken anemia virus; D014764:Viral Proteins