Prof. Dr. Ethel-Michele de Villiers

Mechanisms under investigation for a role of TT viruses in the pathogenesis of disease.

TT viruses (TTV) represent single-stranded circular DNA viruses which persist episomally. They are found globally in the serum of the majority of humans. These infections have not yet been linked to any disease. We recently identified re-arranged TTV molecules, in part as microTTVs (the smallest ones represent only 10% of the viral genome), in part as chimeric molecules between TTV and host cell DNA. These molecules are replicating autonomously, independent of complete TTV genomes. Such episomally persisting molecules contain novel open reading frames which, upon translation, reveal peptide signature motifs similar to reactive components in autoimmune diseases (e.g. celiac disease, rheumatoid arthritis, multiple sclerosis). Chimeric molecules containing TTV and cellular DNA contain in part components of genes influencing cell proliferation. For these reasons we are investigating the possible role of these re-arranged molecules in autoimmune diseases and human cancers.