Construction and biological activity of a full-length molecular clone of human Torque teno virus (TTV) genotype 6

Laura Kakkola, Johanna Tommiska, Linda C Boele, Simo Miettinen, Tea Blom, Tuija Kekarainen, Jianming Qiu, David Pintel, Rob C Hoeben, Klaus Hedman, Maria Söderlund-Venermo

Research output: Contribution to journalArticleScientificpeer-review


Torque teno virus (TTV) is a non-enveloped human virus with a circular negative-sense (approximately 3800 nucleotides) ssDNA genome. TTV resembles in genome organization the chicken anemia virus, the animal pathogen of the Circoviridae family, and is currently classified as a member of a new, floating genus, Anellovirus. Molecular and cell biological research on TTV has been restricted by the lack of permissive cell lines and functional, replication-competent plasmid clones. In order to examine the key biological activities (i.e. RNA transcription and DNA replication) of this still poorly characterized ssDNA virus, we cloned the full-length genome of TTV genotype 6 and transfected it into cells of several types. TTV mRNA transcription was detected by RT-PCR in all the cell types: KU812Ep6, Cos-1, 293, 293T, Chang liver, Huh7 and UT7/Epo-S1. Replicating TTV DNA was detected in the latter five cell types by a DpnI-based restriction enzyme method coupled with Southern analysis, a novel approach to assess TTV DNA replication. The replicating full-length clone, the cell lines found to support TTV replication, and the methods presented here will facilitate the elucidation of the molecular biology and the life cycle of this recently identified human virus.
Original languageEnglish
JournalThe FEBS Journal
Issue number18
Pages (from-to)4719-4730
Number of pages12
Publication statusPublished - 2007
MoE publication typeA1 Journal article-refereed

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